A Comparison of Chain Saws, Brushcutters, and Machetes in Thinning a Young Conifer Plantation in the Sierra Nevada

Abstract Chain saws, power brushcutters, and machetes were used in thinning an 8-year-old, 14.5 ac mixed conifer plantation in the Sierra Nevada. A comparison of production rates indicated no significant difference between chainsaws and machetes, with brushcutter production rates significantly lower than the other two tools. Differences in production rates were not attributable to tree size or number of trees per acre. Inefficiency of brushcutters was attributable to greater maintenance and downtime as compared to the other two tools. Further comparisons of these tools could be useful in determining the least expensive method of conducting precommercial thinnings in young mixed conifer plantations. West. J. Appl. For. 4(2):60-62, April 1989.

Download Full-text

Opportunities for winter prescribed burning in mixed conifer plantations of the Sierra Nevada

Fire Ecology ◽

10.1186/s42408-021-00120-5 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Robert A. York ◽

Jacob Levine ◽

Kane Russell ◽

Joseph Restaino

Keyword(s):

Sierra Nevada ◽

Pinus Ponderosa ◽

Prescribed Burning ◽

Winter Season ◽

Basal Area ◽

Weather Conditions ◽

Shrub Cover ◽

Mixed Conifer ◽

Planted Forests ◽

Conifer Plantations

Abstract Background Young, planted forests are particularly vulnerable to wildfire. High severity effects in planted forests translate to the loss of previous reforestation investments and the loss of future ecosystem service gains. We conducted prescribed burns in three ~35-year-old mixed conifer plantations that had previously been masticated and thinned during February in order to demonstrate the effectiveness of winter burning, which is not common in the Sierra Nevada, California. Results On average, 59% of fine fuels were consumed and the fires reduced shrub cover by 94%. The average percent of crown volume that was damaged was 25%, with no mortality observed in overstory trees 1 year following the fires. A plot level analysis of the factors of fire effects did not find strong predictors of fuel consumption. Shrub cover was reduced dramatically, regardless of the specific structure that existed in plots. We found a positive relationship between crown damage and the two variables of Pinus ponderosa relative basal area and shrub cover. But these were not particularly strong predictors. An analysis of the weather conditions that have occurred at this site over the past 20 years indicated that there have consistently been opportunities to conduct winter burns. On average, 12 days per winter were feasible for burning using our criteria. Windows of time are short, typically 1 or 2 days, and may occur at any time during the winter season. Conclusions This study demonstrates that winter burning can be an important piece of broader strategies to reduce wildfire severity in the Sierra Nevada. Preparing forest structures so that they can be more feasible to burn and also preparing burn programs so that they can be nimble enough to burn opportunistically during short windows are key strategies. Both small landowners and large agencies may be able to explore winter burning opportunities to reduce wildfire severity.

Download Full-text

Fuel treatment effects on stand-level carbon pools, treatment-related emissions, and fire risk in a Sierra Nevada mixed-conifer forestPublication No. 143 of the National Fire and Fire Surrogate Project.

Canadian Journal of Forest Research ◽

10.1139/x09-081 ◽

2009 ◽

Vol 39 (8) ◽

pp. 1538-1547 ◽

Cited By ~ 60

Author(s):

Scott L. Stephens ◽

Jason J. Moghaddas ◽

Bruce R. Hartsough ◽

Emily E.Y. Moghaddas ◽

Nicholas E. Clinton

Keyword(s):

Sierra Nevada ◽

Prescribed Fire ◽

Fire Risk ◽

C Sequestration ◽

Mixed Conifer ◽

Management Actions ◽

C Stocks ◽

Significant Difference ◽

Live Tree ◽

And Control

Policies have been enacted to encourage carbon (C) sequestration through afforestation, reforestation, and other silvicultural practices; however, the effects of wildfires on forest C stocks are poorly understood. We present information from Sierran mixed-conifer forests regarding how control, mechanical, prescribed-fire, and mechanical followed by prescribed-fire treatments affected C pools. Secondly, we report CO2 emissions from machinery and burning associated with the treatments. Lastly, the effects of treatments on the potential for C loss to wildfire are presented. The amount of aboveground C in live trees was significantly reduced in mechanical-only and mechanical plus fire treatments; C contained in dead trees was not significantly different. There was no significant difference in aboveground live and dead tree C between the fire-only and control treatments. Fire-only and mechanical plus fire treatments emitted significantly more CO2 than the mechanical treatment and control. Modeling results for the control demonstrated 90% of the live tree C had a high (>75%) chance of being killed in a wildfire; in contrast, all three active treatments had low vulnerabilities to C loss. With wildfire severity increasing in most Sierran forests, management actions designed to increase fire resistance are justified for long-term C sequestration.

Download Full-text

Damage and mortality patterns in young mixed conifer plantations following prescribed fires in the Sierra Nevada, California

Forest Ecology and Management ◽

10.1016/j.foreco.2016.05.049 ◽

2016 ◽

Vol 376 ◽

pp. 193-204 ◽

Cited By ~ 6

Author(s):

Robin S. Bellows ◽

Ariel C. Thomson ◽

Kate J. Helmstedt ◽

Robert A. York ◽

Matthew D. Potts

Keyword(s):

Sierra Nevada ◽

Prescribed Fires ◽

Mixed Conifer ◽

Conifer Plantations

Download Full-text

Opportunities for winter prescribed burning in mixed conifer plantations of the Sierra Nevada

10.21203/rs.3.rs-423745/v1 ◽

2021 ◽

Author(s):

Robert York ◽

Jacob Levine ◽

Kane Russell ◽

Joseph Restaino

Keyword(s):

Sierra Nevada ◽

Pinus Ponderosa ◽

Prescribed Burning ◽

Winter Season ◽

Basal Area ◽

Weather Conditions ◽

Shrub Cover ◽

Mixed Conifer ◽

Planted Forests ◽

Conifer Plantations

Abstract Background Young, planted forests are particularly vulnerable to wildfire. High severity effects in planted forests translate to the loss of previous reforestation investments and the loss of future ecosystem service gains. We conducted prescribed burns in three ~ 35 year-old mixed conifer plantations during February in order to demonstrate the effectiveness of winter burning, which is not common in the Sierra Nevada, California. Results On average, 59% of fine fuels were consumed and the fires reduced shrub cover by 94%. The average percent of crown volume that was damaged was 25%, with no mortality observed in overstory trees one year following the fires. A plot-level analysis of the factors of fire effects did not find strong predictors of fuel consumption. Shrub cover was reduced dramatically, regardless of the specific structure that existed in plots. We found a positive relationship between crown damage and the two variables of Pinus ponderosa relative basal area and shrub cover. But these were not particularly strong predictors. An analysis of the weather conditions that have occurred at this site over the past 20 years indicated that there has consistently been opportunities to conduct winter burns. Windows of time are short, typically one or two days, and may occur at any time during the winter season. Conclusions This study demonstrates that winter burning can be an important piece of broader strategies to reduce wildfire severity in the Sierra Nevada. Preparing forest structures so that they can be feasible to burn and also preparing burn programs so that they can be nimble enough to burn opportunistically during short windows during the winter are key strategies.

Download Full-text

Writing in Aphasia Rehabilitation: Cursive vs Manuscript

Journal of Speech and Hearing Disorders ◽

10.1044/jshd.4104.523 ◽

1976 ◽

Vol 41 (4) ◽

pp. 523-529 ◽

Cited By ~ 3

Author(s):

Daniel R. Boone ◽

Harold M. Friedman

Keyword(s):

Correct Response ◽

The Other ◽

Read Aloud ◽

Writing Style ◽

Reading And Writing ◽

Manual Responses ◽

Significant Difference ◽

Written Form ◽

The Individual ◽

Read Number

Reading and writing performance was observed in 30 adult aphasic patients to determine whether there was a significant difference when stimuli and manual responses were varied in the written form: cursive versus manuscript. Patients were asked to read aloud 10 words written cursively and 10 words written in manuscript form. They were then asked to write on dictation 10 word responses using cursive writing and 10 words using manuscript writing. Number of words correctly read, number of words correctly written, and number of letters correctly written in the proper sequence were tallied for both cursive and manuscript writing tasks for each patient. Results indicated no significant difference in correct response between cursive and manuscript writing style for these aphasic patients as a group; however, it was noted that individual patients varied widely in their success using one writing form over the other. It appeared that since neither writing form showed better facilitation of performance, the writing style used should be determined according to the individual patient’s own preference and best performance.

Download Full-text

Multi-Center Study of Thromboplastin Calibration Precision – Influence of Reagent Species, Composition, and International Sensitivity Index (ISI)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651544 ◽

1993 ◽

Vol 69 (01) ◽

pp. 035-040 ◽

Cited By ~ 12

Author(s):

A M H P van den Besselaar ◽

R M Bertina

Keyword(s):

Oral Anticoagulants ◽

International Normalized Ratio ◽

The Other ◽

World Health ◽

Rabbit Brain ◽

Sensitivity Index ◽

Bovine Plasma ◽

Significant Difference ◽

The Mean ◽

International Sensitivity Index

SummaryFour thromboplastin reagents were tested by 18 laboratories in Europe, North-America, and Australasia, according to a detailed protocol. One thromboplastin was the International Reference Preparation for ox brain thromboplastin combined with adsorbed bovine plasma (coded OBT/79), and the second was a certified reference material for rabbit brain thromboplastin, plain (coded CRM 149R). The other two thromboplastin reagents were another rabbit plain brain thromboplastin (RP) with a lower ISI than CRM 149R and a rabbit brain thromboplastin combined with adsorbed bovine plasma (RC). Calibration of the latter two reagents was performed according to methods recommended by the World Health Organization (W. H. O.).The purpose of this study was to answer the following questions: 1) Is the calibration of the RC reagent more precise against the bovine/combined (OBT/79) than against the rabbit/plain reagent (CRM 149R)? 2) Is the precision of calibration influenced by the magnitude of the International Sensitivity Index (ISI)?The lowest inter-laboratory variation of ISI was observed in the calibration of the rabbit/plain reagent (RP) against the other rabbit/plain reagent (CRM 149R) (CV 1.6%). The highest interlaboratory variation was obtained in the calibration of rabbit/plain (RP) against bovine/combined (OBT/79) (CV 5.1%). In the calibration of the rabbit/combined (RC) reagent, there was no difference in precision between OBT/79 (CV 4.3%) and CRM 149R (CV 4.2%). Furthermore, there was no significant difference in the precision of the ISI of RC obtained with CRM 149R (ISI = 1.343) and the rabbit/plain (RP) reagent with ISI = 1.14. In conclusion, the calibration of RC could be performed with similar precision with either OBT/79 or CRM 149R, or RP.The mean ISI values calculated with OBT/79 and CRM 149R were practically identical, indicating that there is no bias in the ISI of these reference preparations and that these reference preparations have been stable since their original calibration studies in 1979 and 1987, respectively.International Normalized Ratio (INR) equivalents were calculated for a lyophilized control plasma derived from patients treated with oral anticoagulants. There were small but significant differences in the mean INR equivalents between the bovine and rabbit thromboplastins. There were no differences in the interlaboratory variation of the INR equivalents, when the four thromboplastins were compared.

Download Full-text

IMMUNOLOGICAL REACTIVITY OF INSULIN IN HUMAN SERUM

Acta Endocrinologica ◽

10.1530/acta.0.0530673 ◽

1966 ◽

Vol 53 (4) ◽

pp. 673-680 ◽

Cited By ~ 5

Author(s):

Torsten Deckert ◽

Kai R. Jorgensen

Keyword(s):

Normal Subjects ◽

The Other ◽

Human Pancreas ◽

Porcine Pancreas ◽

Crystalline Insulin ◽

Endogenous Insulin ◽

Significant Difference ◽

Human Sera ◽

Normal Human ◽

The One

ABSTRACT The purpose of this study was to investigate whether a difference could be demonstrated between crystalline insulin extracted from normal human pancreas, and crystalline insulin extracted from bovine and porcine pancreas. Using Hales & Randle's (1963) immunoassay no immunological differences could be demonstrated between human and pig insulin. On the other hand, a significant difference was found, between pig and ox insulin. An attempt was also made to determine whether an immunological difference could be demonstrated between crystalline pig insulin and crystalline human insulin from non diabetic subjects on the one hand and endogenous, circulating insulin from normal subjects, obese subjects and diabetic subjects on the other. No such difference was found. From these experiments it is concluded that endogenous insulin in normal, obese and diabetic human sera is immunologically identical with human, crystalline insulin from non diabetic subjects and crystalline pig insulin.

Download Full-text

Pengaruh Luka Iris Pada Tikus Dengan Paparan Hidrogen Peroxida 3% terhadap Epitelisasi dan Pembentukan Eksudat pada Permukaan Epitel Kulit.

Hang Tuah Medical journal ◽

10.30649/htmj.v17i2.438 ◽

2020 ◽

Vol 17 (2) ◽

pp. 172

Author(s):

HARMAN AGUSAPUTRA ◽

MARIA SUGENG ◽

AYLY SOEKAMTO ◽

ATIK WULANDARI

Keyword(s):

Hydrogen Peroxide ◽

Wound Healing ◽

The Other ◽

Delayed Wound Healing ◽

Peroxide Group ◽

Hemostatic Effect ◽

Significant Difference ◽

Negative Effect ◽

Wound Healing Effect ◽

Epithelial Growth

AbstractBackground: Hydrogen peroxide (H2O2) as antiseptic has been used frequently to clean woundsin in hospitals and clinics. Hydrogen peroxide has the effectof strong oxidative that can kill pathogens. It can clean up debris and necrotic tissuesin wounds. Hydrogen peroxidealso has hemostatic effect that can help to stop bleeding. Besides antiseptic effects, hydrogen peroxide i s suspected of having negative effect in wound healing. Hydrogen peroxide presumably could cause delayed wound healing by exudate formation and delayed epithelial growth.Method: This study was conducted in the laboratory using 48 white mice that were divided into 2 groups. All the mice were purposely wounded. Afterwards in one group the wounds were clean up using hydrogen peroxide, while in the other group without hydrogen peroxide as control. The wounds of both groups were observed on day 1, day 3 and day 7. On day 1 and day 3, both groups did not show significant difference.Result : on day 7 showed that the wound healing in hydrogen peroxide group were delayed. Fifty percent of them had the formation of exudate and 62.5% of them showed delayed epithelial growth.Conclusion : This study could show hydrogen peroxide as wound antiseptic has delayed wound healing effect.Keyword: hydrogen peroxide, wound healing

Download Full-text

Comparative Evaluation of Immediate Bond Strength to Bleached Enamel Following Application of Various Antioxidant Solutions

Dental Journal of Advance Studies ◽

10.1055/s-0038-1672088 ◽

2017 ◽

Vol 05 (02) ◽

pp. 084-089

Author(s):

Alisha Dhingra ◽

Ashu Gupta ◽

Anshu Minocha ◽

Nayantara Sen

Keyword(s):

Bond Strength ◽

Shear Bond Strength ◽

Grape Seed Extract ◽

Grape Seed ◽

Seed Extract ◽

The Other ◽

Sodium Ascorbate ◽

Group V ◽

Group I ◽

Significant Difference

Abstract Aim: The aim of this study was to compare the reversal of shear bond strength of composite to bleached enamel immediately after bleaching followed by application of various antioxidant solutions. Material and Methods: Seventy central incisors were divided into seven groups. Groups I and II served as unbleached and bleached controls respectively. Groups III, IV, V, VI and VII served as the experimental groups and were subjected to 37.5% hydrogen peroxide bleaching followed by 10 min application of 10% sodium ascorbate, 25% alpha-tocopherol, 6.5% grape seed extract, 5% lycopene and 5% green tea extract respectively. Following composite bonding, shear bond strength was determined and the results were analyzed using ANOVA followed by Post Hoc Multiple Comparisons test. Results: The bond strength values for Group I (positive control) were maximum and significantly different than all the other groups except Grape seed extract group (Group V). When compared to Group II (bleached control), all the groups showed significantly higher bond strength. Significant difference in the bond strength values were seen between Group III (10% sodium ascorbate) and Group V. Also values for Group V were significantly different from Group VI (5% lycopene). All the other values showed insignificantly different results. Conclusion: All the antioxidant solutions improved the shear bond strength values after bleaching but only Grape seed extract application reversed the values to the non bleached levels. Lycopene was least effective. Other antioxidants showed comparable results.

Download Full-text

Energy Balance Indicators during the Transition Period and Early Lactation of Purebred Holstein and Simmental Cows and Their Crosses

Animals ◽

10.3390/ani11020309 ◽

2021 ◽

Vol 11 (2) ◽

pp. 309

Author(s):

Deise Aline Knob ◽

André Thaler Neto ◽

Helen Schweizer ◽

Anna C. Weigand ◽

Roberto Kappes ◽

...

Keyword(s):

Energy Balance ◽

Milk Yield ◽

Milk Composition ◽

Negative Energy ◽

The Other ◽

Negative Energy Balance ◽

Metabolic Energy ◽

Genetic Groups ◽

Significant Difference ◽

Fat Thickness

Crossbreeding in dairy cattle has been used to improve functional traits, milk composition, and efficiency of Holstein herds. The objective of the study was to compare indicators of the metabolic energy balance, nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, body condition score (BCS) back fat thickness (BFT), as well as milk yield and milk composition of Holstein and Simmental cows, and their crosses from the prepartum period until the 100th day of lactation at the Livestock Center of the Ludwig Maximilians University (Munich, Germany). In total, 164 cows formed five genetic groups according to their theoretic proportion of Holstein and Simmental genes as follows: Holstein (100% Holstein; n = 9), R1-Hol (51–99% Holstein; n = 30), first generation (F1) crossbreds (50% Holstein, 50% Simmental; n = 17), R1-Sim (1–49% Holstein; n = 81) and Simmental (100% Simmental; n = 27). The study took place between April 2018 and August 2019. BCS, BFT blood parameters, such as BHBA, glucose, and NEFA were recorded weekly. A mixed model analysis with fixed effects breed, week (relative to calving), the interaction of breed and week, parity, calving year, calving season, milking season, and the repeated measure effect of cow was used. BCS increased with the Simmental proportion. All genetic groups lost BCS and BFT after calving. Simmental cows showed lower NEFA values. BHBA and glucose did not differ among genetic groups, but they differed depending on the week relative to calving. Simmental and R1-Sim cows showed a smaller effect than the other genetic groups regarding changes in body weight, BCS, or back fat thickness after a period of a negative energy balance after calving. There was no significant difference for milk yield among genetic groups, although Simmental cows showed a lower milk yield after the third week after calving. Generally, Simmental and R1-Simmental cows seemed to deal better with a negative energy balance after calving than purebred Holstein and the other crossbred lines. Based on a positive heterosis effect of 10.06% for energy corrected milk (ECM), the F1, however, was the most efficient crossbred line.

Download Full-text