Forest floor fuel dynamics in mixed-oak forests of south-eastern Ohio

2006 ◽  
Vol 15 (4) ◽  
pp. 479 ◽  
Author(s):  
John B. Graham ◽  
Brian C. McCarthy
Keyword(s):  
Repeated Measures ◽  
Forest Floor ◽  
Fire Regime ◽  
Woody Debris ◽  
Oak Forests ◽  
Fuel Loading ◽  
South Eastern ◽  
Silvicultural Treatments ◽  
Fuel Dynamics ◽  
Over Time

Silvicultural treatments alter fuel dynamics in forested systems, which may alter fire regime. Effects of thinning and prescribed fire on forest-floor fuels were studied in mixed-oak forests of south-eastern Ohio to examine fuel dynamics over time. Fuel characteristics were measured before, immediately after, and 3 years following fire and thinning treatments along 20-m transects (n = 432) following Brown’s planar intersect method. Measurements were taken to determine litter, duff, 1-h, 10-h, 100-h, and 1000-h sound (1000S) or rotten (1000R) fuel mass. Coarse woody debris (CWD) was sampled on 432 additional 80-m2 belt-transects. Repeated-measures analysis of variance with post-hoc Bonferonni comparisons was used to analyse the change in the fuels over time. The specific effects of silvicultural treatments varied over time with changes in larger, sound fuels (1000S and CWD) persisting longer than changes to finer (litter, duff, 1-h, 10-h, and 100-h) or less-sound (1000R) fuels, which appear to be more transient. Unlike in western North America where fuels accumulate over time, decomposition and productivity appear comparable in eastern mixed-oak forests. Aside from their impact on decomposition or productivity rates, silvicultural treatments appear to have little impact on fine-fuel loading in these systems.

scholarly journals Post-fire fuel succession in a rare California, USA, closed-cone conifer

Fire Ecology ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Bret A. McNamara ◽  
Jeffrey M. Kane ◽  
David F. Greene
Keyword(s):  
Moisture Content ◽  
Short Interval ◽  
Fire Behavior ◽  
Fire Regimes ◽  
Stand Age ◽  
Fuel Loading ◽  
Cone Production ◽  
Time Since Fire ◽  
Fuel Dynamics ◽  
Over Time

Abstract Background Increasing frequency and size of wildfires over the past few decades have prompted concerns that populations of obligate seeding species may be vulnerable to repeat, short-interval fires that occur prior to these species reaching maturity. The susceptibility of populations to this risk is partially dependent on the amount and characteristics of fuel loading over time and their influence on fire behavior and effects. This study characterized fuel dynamics and modeled fire behavior across a time-since-fire chronosequence in stands of the rare, serotinous conifer, Baker cypress (Hesperocyparis bakeri [Jeps.] Bartel), ranging in age between 3 and 147 years post fire. Results Litter and fine woody fuel loading (1- to 100-hour) were highest in the 10-year-old and 147-year-old stands, while coarse fuel loading (1000-hour) peaked in the 10-year-old stand and subsequently decreased with time since fire. Duff loading consistently increased with time since fire. Cone production had not occurred in the first 10 yr of stand development. Foliar moisture content in Baker cypress was inversely correlated with stand age, and older foliage had lower moisture content than younger foliage. Modeled surface fire behavior was highest in the 10-year-old and 107-year-old stands in accordance with higher litter, fine woody fuel, or shrub fuel accumulation. While foliar moisture content was higher in younger stands and influenced the critical fireline intensity, we did not observe changes in fire type. Conclusions Fine-fuel loading in Baker cypress stands followed a U-shaped pattern over time (first decreasing, then stable, then increasing), consistent with findings in other forests with stand-replacing fire regimes. Our results indicated that early-successional stages of Baker cypress forests have sufficient fuels to allow for the spread of wildfire and 10-year-old stands could burn with substantive fire behavior prior to cone production. Whenever possible, we recommend suppressing wildfire in stands less than 20 yr old to avoid substantial decreases or local extirpation of these rare Baker cypress populations. Our results highlight the importance of knowing the cone production patterns, fuel dynamics, and corresponding fire behavior over the development of obligate-seeder species to assess the risk of population loss due to short-interval fires.

scholarly journals Clinical characterization of dysautonomia in long COVID-19 patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicolas Barizien ◽  
Morgan Le Guen ◽  
Stéphanie Russel ◽  
Pauline Touche ◽  
Florent Huang ◽  
...  
Keyword(s):  
Mixed Models ◽  
Repeated Measures ◽  
Physical Medicine ◽  
Persistent Symptoms ◽  
Index Changes ◽  
Changes Over Time ◽  
And Control ◽  
Testing Group ◽  
Over Time

AbstractIncreasing numbers of COVID-19 patients, continue to experience symptoms months after recovering from mild cases of COVID-19. Amongst these symptoms, several are related to neurological manifestations, including fatigue, anosmia, hypogeusia, headaches and hypoxia. However, the involvement of the autonomic nervous system, expressed by a dysautonomia, which can aggregate all these neurological symptoms has not been prominently reported. Here, we hypothesize that dysautonomia, could occur in secondary COVID-19 infection, also referred to as “long COVID” infection. 39 participants were included from December 2020 to January 2021 for assessment by the Department of physical medicine to enhance their physical capabilities: 12 participants with COVID-19 diagnosis and fatigue, 15 participants with COVID-19 diagnosis without fatigue and 12 control participants without COVID-19 diagnosis and without fatigue. Heart rate variability (HRV) during a change in position is commonly measured to diagnose autonomic dysregulation. In this cohort, to reflect HRV, parasympathetic/sympathetic balance was estimated using the NOL index, a multiparameter artificial intelligence-driven index calculated from extracted physiological signals by the PMD-200 pain monitoring system. Repeated-measures mixed-models testing group effect were performed to analyze NOL index changes over time between groups. A significant NOL index dissociation over time between long COVID-19 participants with fatigue and control participants was observed (p = 0.046). A trend towards significant NOL index dissociation over time was observed between long COVID-19 participants without fatigue and control participants (p = 0.109). No difference over time was observed between the two groups of long COVID-19 participants (p = 0.904). Long COVID-19 participants with fatigue may exhibit a dysautonomia characterized by dysregulation of the HRV, that is reflected by the NOL index measurements, compared to control participants. Dysautonomia may explain the persistent symptoms observed in long COVID-19 patients, such as fatigue and hypoxia. Trial registration: The study was approved by the Foch IRB: IRB00012437 (Approval Number: 20-12-02) on December 16, 2020.

scholarly journals Acute Comparative Effect of Foam Rolling and Static Stretching on Range of Motion in Rowers

2021 ◽  
Vol 13 (7) ◽  
pp. 3631
Author(s):  
Alfonso Penichet-Tomas ◽  
Basilio Pueo ◽  
Marta Abad-Lopez ◽  
Jose M. Jimenez-Olmedo
Keyword(s):  
Range Of Motion ◽  
Repeated Measures ◽  
Static Stretching ◽  
Foam Rolling ◽  
Significant Difference ◽  
Post Test ◽  
Alternating Treatment Design ◽  
Stroke Amplitude ◽  
Treatment Design ◽  
Over Time

Rowers’ anthropometric characteristics and flexibility are fundamental to increase stroke amplitude and optimize power transfer. The aim of the present study was to analyze the effect of foam rolling and static stretching on the range of motion over time. Eight university rowers (24.8 ± 3.4 yrs., height 182.3 ± 6.5 cm, body mass 79.3 ± 4.6 kg) participated in an alternating treatment design study with two-way repeated measures ANOVA. The sit and reach test was used to measure the range of motion. Both in the foam rolling and in the static stretching method, a pre-test (T0), a post-test (T1), and a post-15-min test (T2) were performed. A significant effect was observed on the range of motion over time (p < 0.001), but not for time x method interaction (p = 0.680). Significant differences were found between T0 and T1 with foam rolling and static stretching (p < 0.001, d = 0.4); p < 0.001, d = 0.6). The differences between T0 and T2 were also significant with both methods (p = 0.001, d = 0.4; p < 0.001, d = 0.4). However, no significant difference was observed between T1 and T2 (p = 1.000, d = 0.1; p = 0.089, d = 0.2). Foam roller and static stretching seem to be effective methods to improve the range of motion but there seems to be no differences between them.

scholarly journals PSVIII-17 Assessment of conformational changes across three parities in sows

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 221-222
Author(s):  
Melanie D Trenhaile-Grannemann ◽  
Ronald M Lewis ◽  
Stephen D Kachman ◽  
Kenneth J Stalder ◽  
Benny E Mote
Keyword(s):  
Body Size ◽  
Body Length ◽  
Conformational Changes ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Random Effect ◽  
Joint Angles ◽  
Body Depth ◽  
Conformation Changes ◽  
Over Time

Abstract Conformation-based sow selection is performed prior to reaching mature size, yet little is known about how conformation changes as growth continues. To assess conformation changes, 9 conformational traits were objectively measured at 12 discrete time points between 112 d of age and parity 3 weaning on 622 sows in 5 cohorts. The 9 traits included 5 body size traits (body length, body depth at the shoulder and flank, and height at the shoulder and flank) and 4 joint angles (knee, hock, and front and rear pastern). Data were analyzed with a repeated measures model (SAS V 9.4) including cohort and time point as fixed effects, sire as a random effect, and heterogeneous compound symmetry as the covariance structure. Sire variance ranged from 0.16 (body depth shoulder) to 2.00 (body length) cm2 for body size traits and 2.28 (rear pastern) to 4.22 (front pastern) degrees2 for joint angles. Cohort had an effect on all traits (P &lt; 0.05). All traits displayed changes over time (P &lt; 0.001). Size traits increased between 112 d of age and parity 3 weaning (64.16 vs. 107.57 cm, 26.62 vs. 44.14 cm, 23.32 vs. 36.92 cm, 46.10 vs. 73.55 cm, 49.36 vs. 77.47 cm for body length, body depth shoulder and flank, and height shoulder and flank, respectively); however, they fluctuated within parity by increasing during gestation and decreasing at weaning. Knee angle decreased (164.12 vs. 150.72 degrees) while fluctuating within parity by decreasing in the second half of gestation and increasing after weaning. Front and rear pastern angles decreased over time (60.89 vs. 53.74 degrees and 64.64 vs. 55.50 degrees for front and rear pastern, respectively), while biologically negligible change was observed in hock angle (148.63 vs. 147.48 degrees). Sow conformation changes throughout life, and these changes may require consideration when making selection decisions.

Mass and nutrient content of woody debris and forest floor in western red cedar and western hemlock forests on northern Vancouver Island

1993 ◽  
Vol 23 (6) ◽  
pp. 1052-1059 ◽  
Author(s):  
Rodney J. Keenan ◽  
Cindy E. Prescott ◽  
J.P. Hamish Kimmins
Keyword(s):  
Forest Floor ◽  
Forest Type ◽  
Woody Debris ◽  
Nutrient Content ◽  
Vancouver Island ◽  
Western Hemlock ◽  
N Availability ◽  
Red Cedar ◽  
The Mean ◽  
Western Red Cedar

Biomass and C, N, P, and K contents of woody debris and the forest floor were surveyed in adjacent stands of old-growth western red cedar (Thujaplicata Donn)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH type), and 85-year-old, windstorm-derived, second-growth western hemlock–amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA type) at three sites on northern Vancouver Island. Carbon concentrations were relatively constant across all detrital categories (mean = 556.8 mg/g); concentrations of N and P generally increased, and K generally decreased, with increasing degree of decomposition. The mean mass of woody debris was 363 Mg/ha in the CH and 226 Mg/ha in the HA type. The mean forest floor mass was 280 Mg/ha in the CH and 211 Mg/ha in the HA stands. Approximately 60% of the forest floor mass in each forest type was decaying wood. Dead woody material above and within the forest floor represented a significant store of biomass and nutrients in both forest types, containing 82% of the aboveground detrital biomass, 51–59% of the N, and 58–61% of the detrital P. Forest floors in the CH and HA types contained similar total quantities of N, suggesting that the lower N availability in CH forests is not caused by greater immobilization in detritus. The large accumulation of forest floor and woody debris in this region is attributed to slow decomposition in the cool, wet climate, high rates of detrital input following windstorms, and the large size and decay resistance of western red cedar boles.

scholarly journals Mood and Global Symptom Changes among Psychotherapy Clients with Depressive Personality

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Rachel E. Maddux ◽  
Lars-Gunnar Lundh
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
Psychological Symptoms ◽  
Self Report ◽  
Treatment Results ◽  
Repeated Measures Analysis ◽  
Depressive Personality ◽  
Symptom Changes ◽  
Psychotherapy Clients ◽  
Over Time

The present study assessed the rate of depressive personality (DP), as measured by the self-report instrument depressive personality disorder inventory (DPDI), among 159 clients entering psychotherapy at an outpatient university clinic. The presenting clinical profile was evaluated for those with and without DP, including levels of depressed mood, other psychological symptoms, and global severity of psychopathology. Clients were followed naturalistically over the course of therapy, up to 40 weeks, and reassessed on these variables again after treatment. Results indicated that 44 percent of the sample qualified for DP prior to treatment, and these individuals had a comparatively more severe and complex presenting disposition than those without DP. Mixed-model repeated-measures analysis of variance was used to examine between-groups changes on mood and global severity over time, with those with DP demonstrating larger reductions on both outcome variables, although still showing more symptoms after treatment, than those without DP. Only eleven percent of the sample continued to endorse DP following treatment. These findings suggest that in routine clinical situations, psychotherapy may benefit individuals with DP.

Association between ibrutinib treatment and hypertension

Heart ◽  
2021 ◽  
pp. heartjnl-2021-319110
Author(s):  
Dae Hyun Lee ◽  
Fahad Hawk ◽  
Kieun Seok ◽  
Matthew Gliksman ◽  
Josephine Emole ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Repeated Measures ◽  
Treatment Initiation ◽  
Kinase Inhibitor ◽  
Pressure Change ◽  
Exact Test ◽  
N 93 ◽  
Pressure Changes ◽  
Over Time

BackgroundIbrutinib is a tyrosine kinase inhibitor most commonly associated with atrial fibrillation. However, additional cardiotoxicities have been identified, including accelerated hypertension. The incidence and risk factors of new or worsening hypertension following ibrutinib treatment are not as well known.MethodsWe conducted a retrospective study of 144 patients diagnosed with B cell malignancies treated with ibrutinib (n=93) versus conventional chemoimmunotherapy (n=51) and evaluated their effects on blood pressure at 1, 2, 3 and 6 months after treatment initiation. Descriptive statistics were used to compare baseline characteristics for each treatment group. Fisher’s exact test was used to identify covariates significantly associated with the development of hypertension. Repeated measures analyses were conducted to analyse longitudinal blood pressure changes.ResultsBoth treatments had similar prevalence of baseline hypertension at 63.4% and 66.7%, respectively. There were no differences between treatments by age, sex and baseline cardiac comorbidities. Both systolic and diastolic blood pressure significantly increased over time with ibrutinib compared with baseline, whereas conventional chemoimmunotherapy was not associated with significant changes in blood pressure. Baseline hypertensive status did not affect the degree of blood pressure change over time. A significant increase in systolic blood pressure (defined as more than 10 mm Hg) was noted for ibrutinib (36.6%) compared with conventional chemoimmunotherapy (7.9%) at 1 month after treatment initiation. Despite being hypertensive at follow-up, 61.2% of patients who were treated with ibrutinib did not receive adequate blood pressure management (increase or addition of blood pressure medications). Within the ibrutinib group, of patients who developed more than 20 mm Hg increase in systolic blood pressure, only 52.9% had hypertension management changes.ConclusionsIbrutinib is associated with the development of hypertension and worsening of blood pressure. Cardiologists and oncologists must be aware of this cardiotoxicity to allow timely management of blood pressure elevations.

Classification Based on Multivariate Repeated Measures with Time Effect on Mean Vector and an AR (1) Correlation Structure on the Repeated Measures

2005 ◽  
Vol 57 (1-2) ◽  
pp. 49-66 ◽  
Author(s):  
Anuradba Roy ◽  
Ravindra Khattree
Keyword(s):  
Maximum Likelihood ◽  
Repeated Measures ◽  
Likelihood Estimation ◽  
Covariance Matrices ◽  
Time Effect ◽  
Population Parameters ◽  
Time Effects ◽  
Mean Vectors ◽  
Mean Vector ◽  
Over Time

In repeated measures studies how observations change over time is often of prime interest. Modelling this time effect in the context of discrimination, is the objective of this article. We study the problem of classification with multiple q-variate observations with time effect on each individual. The covariance matrices as well as mean vectors are mordelled respectively to accommodate the correlation between the successive repeated measures and to describe the time effects. Computation schemes for maximum likelihood estimation of required population parameters are provided.

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