A consensus genetic map for Pinus taeda and Pinus elliottii and extent of linkage disequilibrium in two genotype-phenotype discovery populations of Pinua taeda

Treesearch

Jared W. Westbrook; Vikram E. Chhatre; Le-Shin Wu; Srikar Chamala; Leandro Gomide Neves; Patricio Munoz; Pedro J. Martinez-Garcia; David B. Neale; Matias Kirst; Keithanne Mockaitis; C. Dana Nelson; Gary F. Peter; John M. Davis; Craig S. Echt

2015-01-01

A consensus genetic map for Pinus taeda (loblolly pine) and Pinus elliottii (slash pine) was constructed by merging three previously published P. taeda maps with a map from a pseudo-backcross between P. elliottii and P. taeda. The consensus map positioned 3856 markers via...

Leaf-level gas-exchange uniformity and photosynthetic capacity among loblolly pine (Pinus taeda L.) genotypes of contrasting inherent genetic variation

Treesearch

Michael J. Aspinwall; John S. King; Steven E. McKeand; Jean-Christophe Domec

2011-01-01

Variation in leaf-level gas exchange among widely planted genetically improved loblolly pine (Pinus taeda L.) genotypes could impact stand-level water use, carbon assimilation, biomass production, C allocation, ecosystem sustainability and biogeochemical cycling under changing environmental conditions. We examined uniformity in leaf-level light-saturated photosynthesis...

Soil C02 efflux across four age classes of plantation loblolly pine (Pinus taeda L.) on the Virginia Piedmont

Treesearch

P. Eric Wiseman; John R. Seiler

2004-01-01

Soil CO2 efflux resulting from microbial and root respiration is a major component of the forest C cycle. In this investigation, we examined in detail how soil CO2 efflux differs both spatially and temporally with respect to stand age for loblolly pine (Pinus taeda L.) plantations on the Virginia Piedmont...

Factors influencing loblolly pine stand health in Fort Benning, Georgia, USA

Treesearch

Soung Ryoul Ryu; G. Geoff Wang; Joan L. Walker

2013-01-01

Loblolly pine (LBP; Pinus taeda L.) stands provide two-thirds of the existing federally protected red-cockaded woodpecker (RCW; Picoides borealis) habitat in Fort Benning, Georgia, USA. However, LBP in this area is suspected to face a forest decline issue, which may risk the sustainability of the RCW population. Land managers are attempting to convert LBP stands to...

A Consensus Genetic Map for Pinus taeda and Pinus elliottii and Extent of Linkage Disequilibrium in Two Genotype-Phenotype Discovery Populations of Pinus taeda

PubMed Central

Westbrook, Jared W.; Chhatre, Vikram E.; Wu, Le-Shin; Chamala, Srikar; Neves, Leandro Gomide; Muñoz, Patricio; Martínez-García, Pedro J.; Neale, David B.; Kirst, Matias; Mockaitis, Keithanne; Nelson, C. Dana; Peter, Gary F.; Echt, Craig S.

2015-01-01

A consensus genetic map for Pinus taeda (loblolly pine) and Pinus elliottii (slash pine) was constructed by merging three previously published P. taeda maps with a map from a pseudo-backcross between P. elliottii and P. taeda. The consensus map positioned 3856 markers via genotyping of 1251 individuals from four pedigrees. It is the densest linkage map for a conifer to date. Average marker spacing was 0.6 cM and total map length was 2305 cM. Functional predictions of mapped genes were improved by aligning expressed sequence tags used for marker discovery to full-length P. taeda transcripts. Alignments to the P. taeda genome mapped 3305 scaffold sequences onto 12 linkage groups. The consensus genetic map was used to compare the genome-wide linkage disequilibrium in a population of distantly related P. taeda individuals (ADEPT2) used for association genetic studies and a multiple-family pedigree used for genomic selection (CCLONES). The prevalence and extent of LD was greater in CCLONES as compared to ADEPT2; however, extended LD with LGs or between LGs was rare in both populations. The average squared correlations, r2, between SNP alleles less than 1 cM apart were less than 0.05 in both populations and r2 did not decay substantially with genetic distance. The consensus map and analysis of linkage disequilibrium establish a foundation for comparative association mapping and genomic selection in P. taeda and P. elliottii. PMID:26068575

Nitrogen and Phosphorus Use Efficiency in Stands of Loblolly and Slash Pine

Treesearch

Christopher A. Dicus; Thomas J. Dean

2002-01-01

Nitrogen and phosphorus use efficiency (NUE and PUE, respectively), the annual amount of stemwood produced per unit net N or P used in total aboveground production, were examined in 17-year-old pure stands of unthinned loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Englem.) planted at two spacings. Slash pine stands...

Regenerating uneven-aged stands of loblolly and shortleaf pines: the current state of knowledge

Treesearch

Michael G. Shelton; Michael D. Cain

2000-01-01

Periodic regeneration is crucial to creating or sustaining uneven-aged (UEA) stands of loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pines. Although both species are shade intolerant, they have silvical characteristics that are conducive to natural regeneration in UEA stands. Their seed production is fairly consistent...

Relationship between herbaceous layer, stand, and site variables in the Bankhead National Forest, Alabama

Treesearch

Joel C. Zak; Luben D. Dimov; Callie Jo Schweitzer; Stacy L. Clark

2010-01-01

We studied herbaceous layer richness, diversity and cover in stands on the southern Cumberland Plateau. The stands are mixed pine-hardwoods dominated by 25-40-year-old planted loblolly pine (Pinus taeda L.). Scheduled future treatments combining thinning and fire are designed to restore the hardwood component, particularly oak (Quercus...

Production, allocation, and stemwood growth efficiency of Pinus taeda L. stands in response to 6 years of intensive management

Treesearch

Lisa J. Samuelson; Kurt Johnsen; Tom Stokes

2004-01-01

Loblolly pine (Pinus taeda L.) is a highly plastic species with respect to growth responses to forest management. Loblolly pine is the most planted species across the southern United States, a region with the most expansive and intensively managed forest plantations in the world. Management intensity, using tools such as site preparation and...

Determinants of tree quality and lumber value in natural uneven-aged southern pine stands

Treesearch

Jeffrey P. Prestemon; Joseph Buongiorno

2000-01-01

An ordered-probit model was developed to predict tree grade from tree- and stand-level variables, some of which could be changed by management. Applied to uneven-aged mixed loblolly (Pinus taeda L.) - shortleaf pine (Pinus echinata Mill.) stands, the model showed that the grade of pine trees was highly correlated with tree diameter...

Comparison of log quality from even-aged and uneven-aged loblolly pine stands in south Arkansas

Treesearch

James M. Guldin; Michael W. Fitzpatrick

1991-01-01

Log grade, number of knots, and log volume of the first two logs, as well as form class of the butt log, were compared across three broad sawtimber categories among even-aged plantations, even-aged natural stands, and uneven-aged natural stands of loblolly pine (Pinus taeda L .) in Ashley County, AR. Trees from uneven-aged stands had butt logs of...

Effect of seedling stock on the early stand development and physiology of improved loblolly pine (Pinus taeda L.) seedlings

Treesearch

Shakuntala Sharma; Joshua P. Adams; Jamie L. Schuler; Robert L. Ficklin; Don C. Bragg

2016-01-01

This study assessed the effects of spacing and genotype on the growth and physiology of improved loblolly pine (Pinus taeda L.) seedlings from three distinct genotypes planted in Drew County, Arkansas (USA). Genotype had a significant effect on survival and height. Clone CF Var 1 showed greater height and survival compared to other seedlings....

Southern pine beetle in loblolly pine: simulating within stand interactions using the process model SPBLOBTHIN

Treesearch

Brian Strom; J. R. Meeker; J. Bishir; James Roberds; X. Wan

2016-01-01

Pine stand density is a key determinant of damage resulting from attacks by the southern pine beetle (SPB, Dendroctonus frontalis Zimm.). High-density stands of maturing loblolly pine (Pinus taeda L.) are at high risk for losses to SPB, and reducing stand density is the primary tool available to forest managers for preventing and mitigating damage. Field studies are...

Soil CO2 efflux in loblolly pine (Pinus taeda L.) plantations on the virginia Piedmond and South Carolina coastal plain over a rotation-length chronosequence

Treesearch

Christopher M. Gough; John R. Seiler; P. Eric Wiseman; Christopher A. Maier

2005-01-01

We measured soil surface CO2 efflux (Fx) in loblolly pine stands (Pinus taeda L.) located on the Virginia Piedmont (VA) and South Carolina Coastal Plain (SC) in efforts to assess the impact climate, productivity, and cultural practices have on Fs in the managed loblolly pine...

Rehabilitation of Understocked Loblolly-Shortleaf Pine Stands - II. Development of Intermediate and Suppressed Trees Following Release in Natural Stands

Treesearch

James B. Baker; Michael G. Shelton

1998-01-01

Development of 86 intermediate and suppressed loblolly pine (Pinus taeda L.) trees, that had been recently released from overtopping pines and hardwoods, was monitored over a 15 year period. The trees were growing in natural stands on good sites (site index = 90 ft at 50 years) that had been recently cut to stocking levels ranging from 10 to 50 percent. At time of...

Viability of litter-stored Pinus taeda L. seeds after simulated prescribed winter burns

Treesearch

Michael D. Cain; Michael G. Shelton

1998-01-01

Stratified loblolly pine (Pinus taeda L.) seeds were placed at three depths in a reconstructed forest floor and subjected to simulated prescribed winter burns. Within the forest floor, pine seeds were placed at the L/upper-F interface, upper-F/lower-F interface, and lower-F/mineral-soil interface. Wind was generated by electric box-fans. Seeds that...

Seasonal monoterpene and sesquiterpene emissions from Pinus taeda and Pinus virginiana

EPA Science Inventory

Seasonal volatile organic compound emission data from loblolly pine (Pinus taeda) and Virginia pine (Pinus virginiana) were collected using branch enclosure techniques in Central North Carolina, USA. Pinus taeda monoterpene emission rates were at least ten times higher than oxyge...

Results of a long-term thinning study in some natural, even-aged pine stands of the Midsouth

Treesearch

Don C. Bragg

2013-01-01

This paper reports on a long-term thinning study established in stands of naturally seeded loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pine in southern Arkansas and northern Louisiana. Plots were established in 1949–50 and 1954 in previously unmanaged stands, thinned about once every 5 years from age 20 to 60 years...

A comparison of sampling methods for a standing tree acoustic device

Treesearch

Jerry M. Mahon, Jr.; Lewis Jordan; Lawrence R. Schimleck; Alexander Clark, III; Richard F. Daniels

2009-01-01

One method of evaluating potential product performance is the use of acoustic tools for identifying trees with high stiffness. Acoustic velocities for 100 standing loblolly pine (Pinus taeda) trees, obtained with the transmitting and receiving probes placed on the same face and opposite faces, were compared. Significant differences in velocity between the two...

An acoustics operations study for Loblolly pine (Pinus taeda) standing saw timber with different thinning history

Treesearch

Charles Essien; Qingzheng Cheng; Brian K. Via; Edward F. Loewenstein; Xiping Wang

2016-01-01

There is currently a request from landowners in southeastern USA to provide a non-destructive tool that can differentiate the quality between stands of 25 and 30 years of age subjected to different thinning treatments. A typical site with various thinning regimes was used to vary the wood quality and to determine whether acoustics had the ability to seperate for...

Multi-Season Monoterpene and Sesquiterpene Analysis of Pinus taeda Needle Tissue

EPA Science Inventory

Pinus taeda (Loblolly pine) is one of the worlds most important timber crop and accounts for a significant portion of the southeastern U.S. landcover. Biogenic voltile organic compound (BVOC) content was extracted from the tissue material of P. taeda needles and analyzed over a m...

LEAF AREA INDEX (LAI) CHANGE DETECTION ON LOBLOLLY PINE FOREST STANDS WITH COMPLETE UNDERSTORY REMOVAL

EPA Science Inventory

The confounding effect of understory vegetation contributions to satellite derived
estimates of leaf area index (LAI) was investigated on two loblolly pine (Pinus taeda) forest stands located in the southeastern United States. Previous studies have shown that understory can a...

Yield comparisons from even-aged and uneven-aged loblolly-shortleaf pine stands

Treesearch

James M. Guldin; James B. Baker

1988-01-01

Empirical yields for a 36-year management period are presented for seven long-term studies on similar sites in loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands on the upper southern coastal plain of southern Arkansas and northern Louisiana. Total merchantable cubic-fooy yields are highest for conventionally...

Overstory tree status following thinning and burning treatments in mixed pine-hardwood stands on the William B. Bankhead National Forest, Alabama

Treesearch

Callie Jo Schweitzer; Yong Wang

2013-01-01

Prescribed burning and thinning are intermediate stand treatments whose consequences when applied in mixed pine-hardwood stands are unknown. The William B. Bankhead National Forest in northcentral Alabama has undertaken these two options to move unmanaged, 20- to 50-year-old loblolly pine (Pinus taeda L.) plantations towards upland hardwood-dominated...

Composition, biomass, and overstory spatial patterns in a mature pine-hardwood stand in southeastern Arkansas

Treesearch

Don C. Bragg

2013-01-01

A 1.21-ha plot was established in a mature pine–hardwood forest (Hyatt’s Woods) along a low stream terrace in southeastern Arkansas. Compositionally, this stand had considerable arboreal richness, with 26 different tree species ≥9 cm in diameter. Loblolly pine (Pinus taeda) contributed 42% of the stand’s 37.1 m²/ha of basal area;...

Effects of planting density and genotype on loblolly pine stands growing in the mountains of southeastern Oklahoma

Treesearch

Rodney E. Will; Thomas C. Hennessey; Thomas B. Lynch; Robert Heinemann; Randal Holeman; Dennis Wilson; Keith Anderson; Gregory Campbell

2013-01-01

We determined the effects of planting density (4- by 4-, 6- by 6-, 8- by 8-, and 10- by 10-foot spacing) on stand-level height, diameter at breast height, stem volume, basal area, and periodic annual increment for two loblolly pine (Pinus taeda L.) seed sources. Seed sources for the 25-year-old stands were a North Carolina seed source (NCC 8-01) and...

Does Prescribed Burning Have a Place in Regenerating Uneven-Aged Loblolly-Shortleaf Pine Stands?

Treesearch

Michael D. Cain; Michael G. Shelton

2002-01-01

Before the 1981 growing season, a study was installed in southeastern Arkansas to examine the effects of three dormant-season burn intervals (low, moderate, and high frequency) and an unburned treatment on natural regeneration in uneven-aged stands of loblolly and shortleaf pines (Pinus taeda and P. echinata, respectively)....

Estimating long-term carbon sequestration patterns in even- and uneven-aged southern pine stands

Treesearch

Don C. Bragg; James M. Guldin

2010-01-01

Carbon (C) sequestration has become an increasingly important consideration for forest management in North America, and has particular potential in pine-dominated forests of the southern United States. Using existing literature on plantations and long-term studies of naturally regenerated loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine-dominated stands on...

Measurement properties and feasibility of clinical tests to assess sit-to-stand/stand-to-sit tasks in subjects with neurological disease: a systematic review

PubMed Central

Silva, Paula F. S.; Quintino, Ludmylla F.; Franco, Juliane; Faria, Christina D. C. M.

2014-01-01

Background Subjects with neurological disease (ND) usually show impaired performance during sit-to-stand and stand-to-sit tasks, with a consequent reduction in their mobility levels. Objective To determine the measurement properties and feasibility previously investigated for clinical tests that evaluate sit-to-stand and stand-to-sit in subjects with ND. Method A systematic literature review following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) protocol was performed. Systematic literature searches of databases (MEDLINE/SCIELO/LILACS/PEDro) were performed to identify relevant studies. In all studies, the following inclusion criteria were assessed: investigation of any measurement property or the feasibility of clinical tests that evaluate sit-to-stand and stand-to-sit tasks in subjects with ND published in any language through December 2012. The COSMIN checklist was used to evaluate the methodological quality of the included studies. Results Eleven studies were included. The measurement properties/feasibility were most commonly investigated for the five-repetition sit-to-stand test, which showed good test-retest reliability (Intraclass Correlation Coefficient:ICC=0.94-0.99) for subjects with stroke, cerebral palsy and dementia. The ICC values were higher for this test than for the number of repetitions in the 30-s test. The five-repetition sit-to-stand test also showed good inter/intra-rater reliabilities (ICC=0.97-0.99) for stroke and inter-rater reliability (ICC=0.99) for subjects with Parkinson disease and incomplete spinal cord injury. For this test, the criterion-related validity for subjects with stroke, cerebral palsy and incomplete spinal cord injury was, in general, moderate (correlation=0.40-0.77), and the feasibility and safety were good for subjects with Alzheimer's disease. Conclusions The five-repetition sit-to-stand test was used more often in subjects with ND, and most of the measurement properties were

Revisiting the relationship between common weather variables and loblolly-shortleaf pine seed crops in natural stands

Treesearch

Michael D. Cain; Michael G Shelton

2000-01-01

Seed production was monitored during 24 years using seed-collection traps in loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands located in southeast Arkansas, north-central Louisiana, and southwest Mississippi on the southeastern Coastal Plain, USA. Sound seed production was correlated with mean monthly precipitation...

Distinguishing features of loblolly and shortleaf pine seeds: implications for monitoring seed production in mixed stands

Treesearch

Michael G. Shelton; Michael D. Cain

1996-01-01

Monitoring seed production in mixed loblolly pine - shortleaf pine (Pinus taeda L. and Pinus echinata Mill. respectively) stands may require identifying individual seeds by species. Although loblolly pine seeds are on average heavier and larger than those of shortleaf pine, there is considerable overlap in these properties for...

Effect of Harvest Residue Management on Tree Productivity and Carbon Pools during Early Stand Development in a Loblolly Pine Plantation

Treesearch

Chris A. Maier; Kurt H. Johnsen; Phillip Dougherty; Daniel McInnis; Pete Anderson; Steve Patterson

2012-01-01

Soil incorporation of postharvest forest floor or logging residues during site preparation increased mineral soil carbon (C) and nitrogen (N) concentration and had a differential effect on early stand growth in a clonal loblolly pine (Pinus taeda L.) plantation. Incorporating 25 Mg ha

Seasonal photosynthesis and water relations of juvenile loblolly pine relative to stand density and canopy position

Treesearch

Zhenmin Tang; Jim L. Chambers; Mary A. Sword Sayer; James P. Barnett

2003-01-01

To assess the effects of stand density and canopy environment on tree physiology, we measured gas exchange responses of the same needle age class of 16-year-old loblolly pines (Pinus taeda L.) in thinned (512 trees ha-1) and non-thinned treatment plots (2,863 trees ha-1) in central Louisiana....

Composition, structure, and dynamics of a mature, unmanaged, pine-dominated old-field stand in southeastern Arkansas

Treesearch

Don C. Bragg; Eric Heitzman

2009-01-01

This study describes the composition and structure of a mature, second-growthPinus taeda (Loblolly Pine) and Pinus echinata (Shortleaf Pine)-dominatedold-field stand. Now owned by the University of Arkansas, this 22.5-ha parcel justoutside of the city of Monticello, AR, has been protected as a de facto natural area

Relationship of Aboveground Biomass Production Site Index and Soil Characteristics in a Loblolly Pine Stand

Treesearch

Minyi Zhou; Thomas J. Dean

2004-01-01

As a part of the continuing studies of the Cooperative Research in Sustainable Silviculture and Soil Productivity (CRiSSSP), 24 experimental plots in a loblolly pine (Pinus taeda L.) stand have recently been installed near Natchitoches, LA. The plots were uniformly assigned to 3 blocks based on topography (i.e., up slope, midslope, and down slope)....

Timing and magnitude of C partitioning through a young loblolly pine (Pinus taeda L.) stand using 13C labeling and shade treatments.

PubMed

Warren, J M; Iversen, C M; Garten, C T; Norby, R J; Childs, J; Brice, D; Evans, R M; Gu, L; Thornton, P; Weston, D J

2012-06-01

The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on short-term C flux through a forest ecosystem. We exposed eight 7-year-old loblolly pine (Pinus taeda L.) trees to air enriched with (13)CO(2) and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. The impacts of shading on photosynthesis, plant water potential, sap flow, basal area growth, root growth and soil CO(2) efflux rate (CER) were assessed for each tree over a 3-week period. The progression of the (13)C label was concurrently tracked from the atmosphere through foliage, phloem, roots and surface soil CO(2) efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and fine root standing crop, and resulted in greater residual soil water content to 1 m depth. Soil CER was strongly correlated with sap flow on the previous day, but not the current day, with no apparent treatment effect on the relationship. Although there were apparent reductions in new C flux belowground, the HS treatment did not noticeably reduce the magnitude of belowground autotrophic and heterotrophic respiration based on surface soil CER, which was overwhelmingly driven by soil temperature and moisture. The (13)C label was immediately detected in foliage on label day (half-life = 0.5 day), progressed through phloem by Day 2 (half-life = 4.7 days), roots by Days 2-4, and subsequently was evident as respiratory release from soil which peaked between Days 3 and 6. The δ(13)C of soil CO(2) efflux was strongly correlated with phloem δ(13)C on the previous day, or 2 days earlier. While the (13)C label was readily tracked through the ecosystem, the fate of root C

The silvicultural implications of age patterns in two southern pine stands after 72 years of uneven-aged management

Treesearch

Don C. Bragg; James M. Guldin

2015-01-01

A randomized sample of 250 loblolly (Pinus taeda L.) and shortleaf (Pinus echinata Mill.) pine ring counts was collected from the Good and Poor Farm Forestry compartments on the Crossett Experimental Forest. These mature, pine-dominated stands have been managed using uneven-aged silviculture since 1937. Our sample shows that both...

Growth expectations from alternative thinning regimes and prescribed burning in naturally regenerated loblolly-shortleaf pine stands through age 20

Treesearch

Michael D. Cain

1996-01-01

Pine growth was monitored for 14 years after mechanically strip-thinning a dense, naturally regenerated, even-aged stand of 6-year-old loblolly pines (Pinus taeda L.) and shortleaf pines (Pinus echinata Mill.) that averaged 41 000 trees per hectare in southeastern Arkansas, USA. Prescribed winter bums were conducted...

Ice damage effects on an old-field, thinned and fertilized loblolly pine stand in South Carolina

Treesearch

Bryan C. McElvany; Beth W. Richardson; E. David Dickens

2006-01-01

On January 26, 2004, an ice storm impacted 15 South Carolina counties. An established fertilization study area in Clarendon County, SC, was in the affected region. This old-field, thinned, loblolly pine (Pinus taeda L.) stand was fertilized in the spring of 1998. Treatments consisted of: (1) control; (2) poultry litter (7 tons acre-1); and (3)...

Irrigation and fertilization effects on foliar and soil carbon and nitrogen isotope ratios in a loblolly pine stand

Treesearch

Woo-Jung Choi; Scott X. Chang; H. Lee Allen; Daniel L. Kelting; Hee-Myong Ro

2005-01-01

We examined 813C and 815N in needle (current and 1-year-old) and soil samples collected on two occasions (July and September 1999) from a 15-year-old loblolly pine (Pinus taeda L.) stand in an irrigation and fertilization experiment to investigate whether these treatments leave specific isotope signals in...

Short-term impacts of soil amendments on belowground C cycling and soil nutrition in two contrasting Pinus taeda L. genotypes

Treesearch

Michael C Tyree; John R Seiler; Christopher Maier

2011-01-01

We monitored two Pinus taeda L. genotypes, planted in 170 L lysimeters, subjected to different combinations of fertilization and logging residue (LR) incorporation for 1 year. The objectives were to elucidate how soil amendments modified soil biological properties and belowground C cycling, and secondly, to determine if planting of contrasting genotypes have a...

A Simple Competition Assessment System Associated with Intensive Competition Control in Natural Loblolly - Shortleaf Pine Seedling Stands

Treesearch

Michael D. Cain

1989-01-01

A simple competition assessment system was evaluated a.s part of an intensive competition control study in a natural, even-aged stand of loblolly-short-leaf pine (Pinus taeda L.-P. echinata Mill.) seedlings in southern Arkansas. Four levels of competition control were maintained annually for 3 years as follows: (1) no competition control, (2) woody com- petition...

Growth of loblolly pine stands after the first five years of uneven-aged silviculture using single-tree selection

Treesearch

Paul A. Murphy; Michael G. Shelton

1994-01-01

The effects of three levels of residual basal area (40, 60, and 80 ft2/ac), maximum dbh (12, 16, 20 in.) and site index (90 ft) on the growth of loblolly pine (Pinus taeda L.) stands after 5 yr of uneven-aged silviculture were determined from plots located in the south Arkansas and north...

Within and Between Canopy Variabilit of Foliar Nitrogen Concentration for Loblolly and Slash Pine Stands Planted at Different Densities

Treesearch

Rodney E. Will; Greg Barron-Gafford; Robert O. Teskey; Barry D. Shiver

2004-01-01

Mid-summer foliar nitrogen concentrations (N) were measured at three canopy positions (upper, middle, lower), two foliage ages per canopy position (current-year and 1-year-old), and two flushes per age class (first flush and second flush) in 4-year-old loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) stands...

Effects of Alternative Thinning Regimes and Prescribed Burning in Natural, Even-Aged Loblolly-Shortleaf Pine Stands: 25 Year Results

Treesearch

Michael D. Cain; Michael G. Shelton

2003-01-01

In southeastern Arkansas, pine growth was monitored for 19 yr after mechanically strip thinning a dense, naturally regenerated, even-aged stand of 6-yr-old loblolly pines (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) that averaged 16,600 stems/UC. Prescribed winter burns were conducted biennially between ages 9 and 20...

Woody and herbaceous competition effects on stand dynamics and growth of 13-year-old natural, precommercially thinned loblolly and shortleaf pines

Treesearch

Michael D. Cain

1999-01-01

Stand dynamics of naturally regenerated, even-aged, loblolly pines (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) were examined on the Upper Coastal Plain of southeastern Arkansas, U.S.A., following four levels of competition control. Treatments included a check (Ck) with no competition control, woody control (WC),...

Effects of opening size and site preparation method on vegetation development after implementing group selection in a pine-hardwood stand

Treesearch

M.D. Cain; M.G. Shelton

2001-01-01

Three opening sizes (0.25, 0.625, and 1.0 ac) and three site preparation methods (herbicides, mechanical, and an untreated control) were tested in a pine-hardwood stand dominated by loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.) and mixed oaks (Quercus spp.) that was being converted to uneven...

Timing and magnitude of C partitioning through a young loblolly pine ( Pinus taeda L.) stand using 13C labeling and shade treatments

DOE PAGES

Warren, Jeffrey M.; Iversen, Colleen M.; Garten, Jr., Charles T.; ...

2011-12-30

The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on short-term C flux through a forest ecosystem. We exposed eight 7-year-old loblolly pine ( Pinus taeda L.) trees to air enriched with 13CO 2 and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. The impacts of shading on photosynthesis, plantmore » water potential, sap flow, basal area growth, root growth, and soil CO 2 efflux rate (CER) were assessed for each tree over a three-week period. The progression of the 13C label was concurrently tracked from the atmosphere through foliage, phloem, roots, and surface soil CO 2 efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and fine root standing crop, and resulted in greater residual soil water content to 1 m depth. Sap flow was strongly correlated with CER on the previous day, but not the current day, with no apparent treatment effect on the relationship. Although there were apparent reductions in new C flux belowground, the heavy shade treatment did not noticeably reduce the magnitude of belowground autotrophic and heterotrophic respiration based on surface soil CO 2 efflux rate (CER), which was overwhelmingly driven by soil temperature and moisture. The 13C label was immediately detected in foliage on label day (half-life = 0.5 d), progressed through phloem by day 2 (half-life = 4.7 d), roots by day 2-4, and subsequently was evident as respiratory release from soil which peaked between days 3-6. The δ 13C of soil CO 2 efflux was strongly correlated with phloem 13C on the previous day, or two days earlier. While the 13C label was readily tracked through the ecosystem, the fate

Consortium for Accelerated Pine Production Studies (CAPPS): Long-term Trends in Loblolly Pine Stand Productivity and Characteristics In Georgia

Treesearch

B.E. Borders; Rodney E. Will; R. L. Hendrick; D. Markewitz; T. Harrington; R. O. Teskey; A. Clark

2002-01-01

Beginning in 1987, a series of long-term study plots were installed to determine the effects of annual nitrogen fertilization and complete control of competing vegetation on loblolly pine (Pinus taeda L.) stand growth and development. The study had two locations, one at the Dixon State Forest (DSF) near Waycross, GA on the lower coastal plain and...

Stand development and production dynamics of loblolly pine under a range of cultural treatments in north-central Florida USA

Treesearch

Timothy A. Martin; Eric J. Jokela

2004-01-01

The objectives of this study were to examine the effects of stand development and soil nutrient supply on processes affecting the productivity of loblolly pine (Pinux taeda L.) over a period approximately equal to a pulpwood rotation (18 years). The experiment consisted of a 2 x 2 factorial combination of complete and sustained weed control and...

Cultural intensity and planting density effects on individual tree stem growth, stand and crown attributes, and stand dynamics in thinned loblolly pine plantations during the age 12- to age 15- year period in the Upper Coastal Plain and Piedmont of the Southeastern United States

Treesearch

Evan Johnson; Michael Kane; Dehai Zhao; Robert Teskey

2015-01-01

Three existing loblolly pine (Pinus taeda L.) installations in the Plantation Management Research Cooperative's Upper Coastal Plain/Piedmont Culture Density Study were used to examine the effects of two cultural intensities, four initial planting densities, and their interactions on stem growth at the individual tree level from age 12 to 15 years and at the stand...

Long-term trends in loblolly pine productivity and stand characteristics in response to thinning and fertilization in the West Gulf region

Treesearch

Mary A. Sword Sayer; Jeffery C. Goelz; Jim L. Chambers; Zhenmin Tang; T.J. Dean; James D. Haywood; Daniel J. Leduc

2004-01-01

Two levels each of thinning and fertilization were applied to a 7-year-old loblolly pine (Pinus taeda L.) plantation on a nitrogen- and phosphorus-deficient West Gulf Coastal Plain site in Louisiana. Levels of thinning were no thinning, or thinning applied 7 and 14 years after stand initiation. Levels of fertilization were no fertilization or...

Hardwood Control Treatments to Enhance Natural Regeneration and Growth of Loblolly-Shortleaf Pines in an Uneven-Aged Stand: 12-Year Results

Treesearch

Michael D. Cain

1999-01-01

To facilitate natural regeneration of loblolly (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) in an overstocked, uneven-aged pine stand in southeastern Arkansas, hardwoods were controlled by either basal injection of Tordon® 101 R, soil application of Velpar® L, or rotary mowing followed by a broadcast spray of Tordon®...

Complete chloroplast genome sequence and comparative analysis of loblolly pine (Pinus taeda L.) with related species

PubMed Central

Khan, Abdul Latif; Khan, Muhammad Aaqil; Shahzad, Raheem; Lubna; Kang, Sang Mo; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung

2018-01-01

Pinaceae, the largest family of conifers, has a diversified organization of chloroplast (cp) genomes with two typical highly reduced inverted repeats (IRs). In the current study, we determined the complete sequence of the cp genome of an economically and ecologically important conifer tree, the loblolly pine (Pinus taeda L.), using Illumina paired-end sequencing and compared the sequence with those of other pine species. The results revealed a genome size of 121,531 base pairs (bp) containing a pair of 830-bp IR regions, distinguished by a small single copy (42,258 bp) and large single copy (77,614 bp) region. The chloroplast genome of P. taeda encodes 120 genes, comprising 81 protein-coding genes, four ribosomal RNA genes, and 35 tRNA genes, with 151 randomly distributed microsatellites. Approximately 6 palindromic, 34 forward, and 22 tandem repeats were found in the P. taeda cp genome. Whole cp genome comparison with those of other Pinus species exhibited an overall high degree of sequence similarity, with some divergence in intergenic spacers. Higher and lower numbers of indels and single-nucleotide polymorphism substitutions were observed relative to P. contorta and P. monophylla, respectively. Phylogenomic analyses based on the complete genome sequence revealed that 60 shared genes generated trees with the same topologies, and P. taeda was closely related to P. contorta in the subgenus Pinus. Thus, the complete P. taeda genome provided valuable resources for population and evolutionary studies of gymnosperms and can be used to identify related species. PMID:29596414

Influence of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing.

PubMed

Karimi, Zanyar; Allahyari, Teimour; Azghani, Mahmood Reza; Khalkhali, Hamidreza

2016-03-01

The present study was an attempt to investigate the effect of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing. Ten healthy subjects were recruited to stand for 2 h in three footwear conditions: barefoot, flat-bottomed shoe and unstable shoe. During standing, lower leg discomfort and EMG activity of medial gastrocnemius (MG) and tibialis anterior (TA) muscles were continuously monitored. Changes in lower leg volume over standing time also were measured. Lower leg discomfort rating reduced significantly while subjects standing on unstable shoe compared to the flat-bottomed shoe and barefoot condition. For lower leg volume, less changes also were observed with unstable shoe. The activity level and variation of right MG muscle was greater with unstable shoe compared to the other footwear conditions; however regarding the left MG muscle, significant difference was found between unstable shoe and flat-bottomed shoe only for activity level. Furthermore no significant differences were observed for the activity level and variation of TA muscles (right/left) among all footwear conditions. The findings suggested that prolonged standing with unstable footwear produces changes in lower leg muscles activity and leads to less volume changes. Perceived discomfort also was lower for this type of footwear and this might mean that unstable footwear can be used as ergonomic solution for employees whose work requires prolonged standing. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A 9-year comparison of hardwood control treatments for enhancing natural regeneration and growth of loblolly-shortleaf pines in an uneven-aged stand

Treesearch

Michael D. Cain

1998-01-01

Preharvest control of hardwoods facilitated natural regeneration of loblolly and shortleaf pines (Pinus taeda L. and P. enchinata Mill.) in an overstocked, uneven-aged stand in southern Arkansas. During spring 1983, hardwoods were controlled by either basal injection of Tordon® 101R, soil application of Velpar® L, or rotary mowing...

Physiological and subjective responses to standing showers, sitting showers, and sink baths.

PubMed

Ohnaka, T; Tochihara, Y; Kubo, M; Yamaguchi, C

1995-09-01

The purpose of this study was to investigate physiological and subjective responses during and after bathing in three different bathing methods. Eight healthy males bathed for 10 minutes, and then rested for 30 minutes. Three kinds of bathing methods - standing shower, sitting shower and sink bath - were adopted in this experiment. Water temperature and flow volume of the showers were kept at 41 degrees C and 11 liter/min, while water temperature of the bath was kept at 40 degrees C. Rectal temperature, skin temperatures and heart rate of the subjects were measured continuously during bathing and the subsequent 30-minute rest. Blood pressure and votes for thermal sensations were recorded before bathing, after 5 and 10 minutes of bathing, and 5, 10, 20 and 30 minutes after bathing. The following results were obtained. 1) Although rectal temperature rose, on the average, by 0.15 degrees C in all bathing methods, there were no significant differences among the three bathing methods at any time in the experiment. 2) Mean skin temperature (Tsk) during the sink bath was significantly higher than that in the standing or sitting shower. After bathing, Tsk of sink bath was slightly higher than those of the remaining conditions, but did not significantly differ among the bathing methods. 3) Heart rate increased gradually during all the bathing methods, however, only HR in the standing shower exceeded 100 beats/min which was significantly higher than those of the two remaining bathing methods. 4) Blood pressure (BP) decreased rapidly during the sink bath in contrast to an increased BP in the sitting and standing showers.

Effect of standing on neurohumoral responses and plasma volume in healthy subjects

NASA Technical Reports Server (NTRS)

Jacob, G.; Ertl, A. C.; Shannon, J. R.; Furlan, R.; Robertson, R. M.; Robertson, D.

1998-01-01

Upright posture leads to rapid pooling of blood in the lower extremities and shifts plasma fluid into surrounding tissues. This results in a decrease in plasma volume (PV) and in hemoconcentration. There has been no integrative evaluation of concomitant neurohumoral and PV shifts with upright posture in normal subjects. We studied 10 healthy subjects after 3 days of stable Na+ and K+ intake. PV was assessed by the Evans blue dye method and by changes in hematocrit. Norepinephrine (NE), NE spillover, epinephrine (Epi), vasopressin, plasma renin activity, aldosterone, osmolarity, and kidney response expressed by urine osmolality and by Na+ and K+ excretion of the subjects in the supine and standing postures were all measured. We found that PV fell by 13% (375 +/- 35 ml plasma) over approximately 14 min, after which time it remained relatively stable. There was a concomitant decrease in systolic blood pressure and an increase in heart rate that peaked at the time of maximal decrease in PV. Plasma Epi and NE increased rapidly to this point. Epi approached baseline by 20 min of standing. NE spillover increased 80% and clearance decreased 30% with 30 min of standing. The increase in plasma renin activity correlated with an increase in aldosterone. Vasopressin increased progressively, but there was no change in plasma osmolarity. The kidney response showed a significant decrease in Na+ and an increase in K+ excretion with upright posture. We conclude that a cascade of neurohumoral events occurs with upright posture, some of which particularly coincide with the decrease in PV. Plasma Epi levels may contribute to the increment in heart rate with maintained upright posture.

Effects of stand development and weather on monthly leaf biomass dynamics of a loblolly pine (Pinus taeda L.) stand

Treesearch

P.M. Dougherty; T.C. Hennessey; Stanley J. Zarnoch; P.t> Stenberg; R.T. Holeman; R.F. Witter

1995-01-01

Annual leaf biomass production, monthly needle accretion and monthly needlefall were measured in an 1l- to 17-year-old thinned stand of loblolly pine. Initial thinning levels were 7.8 m2 ha-1, 12.6 m2 ha-1, and 25.5 m2 ha-1...

Influence of soil porosity on water use in Pinus taeda

Treesearch

G. Hacke; J.S. Sperry; B.E. Ewers; D.S. Ellsworth; K.V.R. Schäfer; R. Oren

2000-01-01

We analyzed the hydraulic constraints imposed on water uptake from soils of different porosities in loblolly pine (Pinus taeda L.) by comparing genetically related and even-aged plantations growing in loam versus sand soil. Water use was evaluated relative to the maximum transpiration rate (Ecrit) allowed by the soil-leaf...

Reference karyotype and cytomolecular map for loblolly pine (Pinus taeda L.)

Treesearch

M. Nurul Islam-faridi; C. Dana Nelson; Thomas L. Kubisiak

2007-01-01

A reference karyotype is presented for loblolly pine (Pinus taeda L., subgenus Pinus , section Pinus, subsection Australes), based on fluorescent in situ hybridization (FISH), using 18s-28s rDNA, 5s rDNA, and Arabidopsis-type telomere repeat sequence (A-type TRS). Well...

Immediate effects of bilateral manipulation of talocrural joints on standing stability in healthy subjects.

PubMed

Alburquerque-Sendín, Francisco; Fernández-de-las-Peñas, César; Santos-del-Rey, Miguel; Martín-Vallejo, Francisco Javier

2009-02-01

The purpose of this study was to investigate the immediate effects of bilateral talocrural joint manipulation on standing stability in healthy subjects. Sixty-two healthy subjects, 16 males and 46 females, aged from 18 to 32 years old (mean: 21+/-3 years old) participated in the study. Subjects were randomly divided into two groups: an intervention group (n=32), who received manipulation of bilateral talocrural joints and a control group (n=30) which did not receive any intervention. Baropodometric and stabilometric evaluations were assessed pre- and 5 min post-intervention by an assessor blinded to the treatment allocation. Intra-group and inter-group comparisons were analysed using appropriate parametric tests. The results indicated that changes on the X coordinate range, length of motion, and mean speed approximated to statistical significance (P=0.06), and changes on the Y coordinate range reached statistical significance (P=0.02). Average X and Y motions, and anterior-posterior or lateral velocities did not show significant differences. Our results showed that bilateral thrust manipulation of the talocrural joint did not modify standing stability, that is, the behavioural pattern of the projection of the centre of pressure, in healthy subjects.

New phenolic esters from the resinous exudate of Haplopappus taeda.

PubMed

Faini, Francesca; Labbé, Cecilia; Torres, René; Rodilla, Jesús M; Silva, Lucía; Delle Monache, Franco

2007-12-01

Two new phenolic esters 9-trans-p-coumaroyloxy-alpha-terpineol (1) and 7-trans-p-coumaroyloxy-taedol (2), both endowed with free radical scavenger activity and cleroda-3,13 (E)-dien-15,18-diol (3) for which a cis stereochemistry at the decalin junction was found, were isolated from the resinous exudate from Haplopappus taeda upper parts.

Effectiveness of standing frame on constipation in children with cerebral palsy: a single-subject study.

PubMed

Rivi, Elena; Filippi, Mariacristina; Fornasari, Elisa; Mascia, Maria Teresa; Ferrari, Adriano; Costi, Stefania

2014-09-01

Children with cerebral palsy (CP) and quadriplegia or severe diplegia suffer from highly reduced mobility and consequent constipation. Clinicians recommend standing frames to exercise the support reaction in this population, sharing the opinion that the upright position may facilitate intestinal transit, although no evidence supports this assumption. We conducted this study to determine the effects of the standing frame on spontaneous evacuation in children with CP. Moreover, we studied its effects on the frequency of induction of evacuation, the characteristics of the stool and the pain suffered by the child due to constipation and/or evacuation. We implemented a single-subject research design in one chronically constipated child with CP and quadriplegia, Gross Motor Function Classification System Level V. To monitor the effects of the standing frame, we measured the outcome of interest throughout the study using a daily diary and the Bristol Stool Scale. This study was approved by the local Ethics Committee. This study has several limitation; primarily, the use of a single-subject research design only makes possible the visual analysis of data obtained from a unique patient. So, by themselves, data obtained do not allow us any generalization for the target population. Future research should verify our results collecting more data and also investigating the effect of the standing-frame on respiratory functions. Although the standing frame did not affect the frequency of evacuations or the characteristics of the stool, its employment reduced the inductions of evacuation and the related pain suffered by the child. However, this study has several limitations, such as the lack of generalization due to the fact that we studied a unique patient and the overall brevity of the study due to external circumstances. Therefore, we suggest future research to verify our results, also investigating the effect of the standing frame on respiratory functions. Relevance to clinical

Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas

Treesearch

Adrian G. Grell; Michael G. Shelton; Eric Heitzman

2005-01-01

Old-growth bottomland hardwood-Pinus taeda L. forests are rare in Arkansas, and the complex relationships between plant communities and environmental conditions have not been well described in these forests. To investigate these relationships, a digital elevation model was developed for a 16.2 ha old-growth bottomland hardwood-Pinus taeda forest in...

Impact of vegetation control and annual fertilization on properties of loblolly pine wood at age 12

Treesearch

Alexander Clark; Bruce E. Borders; Richard F. Daniels

2004-01-01

Loblolly pine (Pinus taeda L.) stands in the Coastal Plain and Piedmont of Georgia were subjected to four intensive silvicultural regimes to monitor and record relative tree growth. Treatments included: intensive mechanical site preparation, complete vegetation control with multiple applications of herbicides, annual high rates of nitrogen...

Fall nitrogen fertilization and the biology of Pinus taeda seedling development

Treesearch

Shi-Jean S. Sung; C.C. Black; T.L. Kormanik; P.A. Counce

1997-01-01

In mid-September when stems and roots of nursery-grown loblolly pine (Pinus taeda L.) seedlings are actively accumulating dry weight (DW), an extra 10, 20, or 40 kg NH4NO3 ha-1 (10N, 20N, 4ON) was applied. Seedlings receiving no extra N (0N) were the controls. The temporal patterns...

Thigmomorphogenesis: the role of ethylene in the response of Pinus taeda and Abies fraseri to mechanical perturbation

NASA Technical Reports Server (NTRS)

Telewski, F. W.; Jaffe, M. J.

1986-01-01

Ethylene production was monitored for 48 h in two half-sibs of Pinus taeda L. grown in the greenhouse and given mechanical perturbation (MP) by flexing; and for 22 h in Abies fraseri (Pursh) Poir. grown in the field and exposed to wind-mediated MP. Both species produced a peak of ethylene 18 h after MP. Seedlings of P. taeda exposed to MP for the duration of the growing season (preconditioned) produced less ethylene compared to non-MP controls, with a peak production at 8 h. One half-sib which responded to MP by an increase in radial growth produced 16 times more ethylene than another half-sib which had no significant change in radial growth. Preconditioned A. fraseri produced no significant quantities of ethylene after MP. The production of wound ethylene appears to be different from MP-induced ethylene. When an ethylene-generating solution was applied to P. taeda seedlings, it mimicked many of the morphological and mechanical characteristics of MP seedlings. The putative role of ethylene in the thigmomorphogenetic response is addressed.

Short-term effects of fertilization on loblolly pine (Pinus taeda L.) physiology

Treesearch

C.M. Gough; J.R. Seiler; Chris A. Maier

2004-01-01

Fertilization commonly increases biomass production in loblolly pine (Pinus taeda L.). However, the sequence of short-term physiological adjustments allowing for the establishment of leaf area and enhanced growth is not well understood. The effects of fertilization on photosynthetic parameters, root respiration, and growth for over 200 d following...

Influences of community composition on biogeochemistry of loblolly pine (Pinus taeda) systems

Treesearch

B.G. Lockaby; J.H. Miller; R.G. Clawson

1995-01-01

Litterfall and decomposition processes were compared among four forest plantations that were dominated by loblolly pine (Pinus taeda L) but that differed.in terms of presence or absence of deciduous and herbaceous components. Based on aboveground litterfall, the pine-only community was the most productive but had the slowest turnover of organic...

Seasonal ectomycorrhizal fungal biomass development on loblolly pine (Pinus taeda L.) seedlings

Treesearch

Shi-Jean S. Sung; L.M. White; D.H. Marx; W.J. Otrosina

1995-01-01

Ergosterol, a membrane sterol found in fungi but not in plants, was used to estimate live mycelia biomass in ectomycorrhizae. Loblolly pine (Pinus taeda L.) seeds were sown in April 1993 and grown with standard nursery culture ractices. Correlations between total seedling ergosterol and visual assessment of mycorrhizal colonization were high during...

Thigmomorphogenesis: anatomical, morphological and mechanical analysis of genetically different sibs of Pinus taeda in response to mechanical perturbation.

PubMed

Telewski, F W; Jaffe, M J

1986-01-01

Twenty-three open pollinated families (half-sibs) and four controlled pollinated families (full-sibs) of Pinus taeda L. (loblolly pine) were grown in a greenhouse and analyzed for changes induced by mechanical perturbation (MP). These changes included inhibition of stem and needle elongation, bracing of branch nodes, and increased radial growth in the direction of the MP. Inhibition of stem elongation was the least variable feature measured. Leaf extension and stem diameter were highly variable between half-sibs. MP induced increased drag in greenhouse grown P. taeda in wind-tunnel tests. In P. taeda, MP induced decreased flexibility and increased elasticity and plasticity of the stem. The increased radial growth of the stems overrode the increase in elasticity, resulting in an overall decrease in flexibility. MP trees had a higher rupture point than non-MP controls. Increased radial growth is a result of more rapid cell divisions of the vascular cambium, resulting in increased numbers of tracheids. The decreased leader growth is partly due to a decreased tracheid length in response to MP.

Thigmomorphogenesis: anatomical, morphological and mechanical analysis of genetically different sibs of Pinus taeda in response to mechanical perturbation

NASA Technical Reports Server (NTRS)

Telewski, F. W.; Jaffe, M. J.

1986-01-01

Twenty-three open pollinated families (half-sibs) and four controlled pollinated families (full-sibs) of Pinus taeda L. (loblolly pine) were grown in a greenhouse and analyzed for changes induced by mechanical perturbation (MP). These changes included inhibition of stem and needle elongation, bracing of branch nodes, and increased radial growth in the direction of the MP. Inhibition of stem elongation was the least variable feature measured. Leaf extension and stem diameter were highly variable between half-sibs. MP induced increased drag in greenhouse grown P. taeda in wind-tunnel tests. In P. taeda, MP induced decreased flexibility and increased elasticity and plasticity of the stem. The increased radial growth of the stems overrode the increase in elasticity, resulting in an overall decrease in flexibility. MP trees had a higher rupture point than non-MP controls. Increased radial growth is a result of more rapid cell divisions of the vascular cambium, resulting in increased numbers of tracheids. The decreased leader growth is partly due to a decreased tracheid length in response to MP.

Loblolly pine: the ecology and culture of loblolly pine (Pinus taeda L.)

Treesearch

Robert P. Schultz

1997-01-01

Loblolly pine ranks as a highly valuable tree for its pulp, paper, and lumber products. In the South, loblolly is planted more than any other conifer. Loblolly Pine: The Ecology and Culture of Loblolly Pine (Pinus taeda L.) adds to the technical foundations laid by Ashe (1915) and Wahlenberg (1960). Agriculture Handbook 713 encompasses genetics, tree...

Exome genotyping, linkage disequilibrium and population structure in loblolly pine (Pinus taeda L.)

Treesearch

Mengmeng Lu; Konstantin V. Krutovsky; C. Dana Nelson; Tomasz E. Koralewski; Thomas D. Byram; Carol A. Loopstra

2016-01-01

Background: Loblolly pine (Pinus taeda L.) is one of the most widely planted and commercially important foresttree species in the USA and worldwide, and is an object of intense genomic research. However, whole genomeresequencing in loblolly pine is hampered by its large size and complexity and a lack of a good...

ECTOMYCORRHIZAL DIVERSITY IN A LOBLOLLY PINE (PINUS TAEDA L.) GENETICS PLANTATION: INFLUENCE OF FERTILIZATION

EPA Science Inventory

Loblolly pine (Pinus taeda L.) Has co-evolved a high dependency on ectomycorrhizal (ECM) associations most likely because its natural range includes soils of varying moisture that are P- and/or N-deficient. Because of its wide geographic distrubition, we would expect its roots t...

Pinus Taeda L. response to fertilization, Herbaceous plant control, and woody plant control

Treesearch

Allan E. Tiarks; James D. Haywood

1986-01-01

On an intensively prepared site, a complete fertilizer applied at planting, and control of herbaceous and woody plants for the first 4 years, increased Pinus taeda L. volume at age 5 to 25.9 m3/ha compared to 11.8 m3/ha without the treatments. The fertilizer and competition control factors affected pine...

Effect of a cane on sit-to-stand transfer in subjects with hemiparesis.

PubMed

Hu, Po-Ting; Lin, Kwan-Hwa; Lu, Tung-Wu; Tang, Pei-Fang; Hu, Ming-Hsia; Lai, Jin-Shin

2013-03-01

The aim of this study was to determine the effect of using a cane on movement time, joint moment, weight symmetry, and muscle activation patterns during sit-to-stand (STS) transfer in healthy subjects and subjects who have had a stroke. Nine subjects with hemiparesis (mean [SD] age, 61.11 [12.83] yrs) and nine healthy adults (mean [SD] age, 63.11 [10.54] yrs) were included. The subjects with hemiparesis performed STS transfer in two randomly assigned conditions: (1) without a cane and (2) with a cane. The healthy subjects performed only STS transfer without a cane. A three-dimensional motion system, force plates, and eletromyography were used to examine STS transfer. The symmetry index between the two limbs was calculated. The movement time of the subjects with hemiparesis in both conditions without a cane and with a cane was longer than that of the healthy subjects without a cane (P < 0.025). However, STS transfer with a cane in the subjects with hemiparesis resulted in shorter movement time, greater knee extensor moment of the paretic limb, and more symmetry of weight bearing than in those without a cane (P < 0.05). The sequence of muscle onset tended to improve with a cane in the subjects with hemiparesis. Cane use may promote more symmetrical STS transfers rather than compensation by the unaffected limb.

Water availability and genetic effects on wood properties of loblolly pine (Pinus taeda)

Treesearch

C. A. Gonzalez-Benecke; T. A. Martin; Alexander Clark; G. F. Peter

2010-01-01

We studied the effect of water availability on basal area growth and wood properties of 11-year-old loblolly pine (Pinus taeda L.) trees from contrasting Florida (FL) (a mix of half-sib families) and South Carolina coastal plain (SC) (a single, half-sib family) genetic material. Increasing soil water availability via irrigation increased average wholecore specific...

Apparent mass matrix of standing subjects exposed to multi-axial whole-body vibration.

PubMed

Tarabini, Marco; Solbiati, Stefano; Saggin, Bortolino; Scaccabarozzi, Diego

2016-08-01

This paper describes the experimental characterisation of the apparent mass matrix of eight male subjects in standing position and the identification of nonlinearities under both mono-axial and dual-axis whole-body vibration. The nonlinear behaviour of the response was studied using the conditioned response techniques considering models of increasing complexity. Results showed that the cross-axis terms are comparable to the diagonal terms. The contribution of the nonlinear effects are minor and can be endorsed to the change of modal parameters during the tests. The nonlinearity generated by the vibration magnitude is more evident in the subject response, since magnitude-dependent effects in the population are overlaid by the scatter in the subjects' biometric data. The biodynamic response is influenced by the addition of a secondary vibration axis and, in case of dual-axis vibrations, the overall magnitude has a marginal contribution. Practitioner Summary: We have measured both the diagonal and cross-axis elements of the apparent mass matrix. The effect of nonlinearities and the simultaneous presence of vibration along two axes are smaller than the inter-subject variability.

Vector Analysis Identify Loblolly Pine (Pinus taeda L.) Phosphorus Deficiency on a Beauregard Soil

Treesearch

A. Bekele; W.H. Hundall; A.E. Tiarks

1999-01-01

We studied the response of densely stocked one-year-old loblolly pine (Pinus taeda L.) to N and P fertilizers on a Beauregard silt loam (fine silty, siliceous, thermic, Plinthaquic Paleudults). A continuous function" experimental design with three replications was used. Each replication consisted of 12 m X 12 m plots, with three trees planted...

Managing Loblolly Pine (Pinus taeda) Stands for the Restoration of Red-cockaded Woodpecker (Picoides borealis) Habitat

DTIC Science & Technology

2014-03-01

hydrometer method (Milford 1997). Climate data from the study period was obtained from the National Climatic Data Center web service, with data for...season after treatment. Throughout this paper , the term “seedling” is used to refer to any loblolly pine individual that established following site... Paper land in southwestern Georgia and found that longleaf pine stands had significantly higher herbaceous richness and diversity than the other

Growth of five families of Pinus taeda L. during three years of ozone exposure

Treesearch

M.B. Adams; J.M. Kelly; G.E. Taylor; N.T. Edwards

1990-01-01

Loblolly pine (Pinus taeda L.) seedlings of five half-sib families were grown for 3 yr in the field in open-top chambers. The seedlings were fumigated during the growing seasons (approximately April-October) with ozone at the following target levels: subambient (CF), ambient (AMB), and ambient+ 60 ppb (AMB+). At the end of the three growing seasons...

The Pinus taeda genome is characterized by diverse and highly diverged repetitive sequences

PubMed Central

2010-01-01

Background In today's age of genomic discovery, no attempt has been made to comprehensively sequence a gymnosperm genome. The largest genus in the coniferous family Pinaceae is Pinus, whose 110-120 species have extremely large genomes (c. 20-40 Gb, 2N = 24). The size and complexity of these genomes have prompted much speculation as to the feasibility of completing a conifer genome sequence. Conifer genomes are reputed to be highly repetitive, but there is little information available on the nature and identity of repetitive units in gymnosperms. The pines have extensive genetic resources, with approximately 329000 ESTs from eleven species and genetic maps in eight species, including a dense genetic map of the twelve linkage groups in Pinus taeda. Results We present here the Sanger sequence and annotation of ten P. taeda BAC clones and Genome Analyzer II whole genome shotgun (WGS) sequences representing 7.5% of the genome. Computational annotation of ten BACs predicts three putative protein-coding genes and at least fifteen likely pseudogenes in nearly one megabase of sequence. We found three conifer-specific LTR retroelements in the BACs, and tentatively identified at least 15 others based on evidence from the distantly related angiosperms. Alignment of WGS sequences to the BACs indicates that 80% of BAC sequences have similar copies (≥ 75% nucleotide identity) elsewhere in the genome, but only 23% have identical copies (99% identity). The three most common repetitive elements in the genome were identified and, when combined, represent less than 5% of the genome. Conclusions This study indicates that the majority of repeats in the P. taeda genome are 'novel' and will therefore require additional BAC or genomic sequencing for accurate characterization. The pine genome contains a very large number of diverged and probably defunct repetitive elements. This study also provides new evidence that sequencing a pine genome using a WGS approach is a feasible goal. PMID

The effect of mid-rotation fertilization on the wood properties of loblolly pine (Pinus taeda)

Treesearch

Finto Antony; Lewis Jordan; Laurence R. Schimleck; Richard F. Daniels; Alexander Clark III

2009-01-01

Mid-rotation fertilization is a common practice in the management of loblolly pine (Pinus taeda L.) plantations, typically providing large improvements in growth. However, concerns exist about the quality of wood produced following fertilization. The objective of this study was to develop an understanding of wood property changes following fertilization. Wood...

Predicting age-age genetic correlations in tree-breeding programs: a case study of Pinus taeda L.

Treesearch

D.P. Gwaze; F.E. Bridgwater; T.D. Byram; J.A. Woolliams; C.G. Williams

2000-01-01

A meta-analysis of 520 parents and 51,439 individuals was used to develop two equations for predicting age-age genetic correlations in Pinus taeda L. Genetic and phenotypic family mean correlations and heritabilities were estimated for ages ranging from 2 to 25 years on 31...

Elbow kinematics during sit-to-stand and stand-to-sit movements.

PubMed

Packer, T L; Wyss, U P; Costigan, P A

1993-11-01

The sit-to-stand and stand-to-sit movements of 10 healthy women (mean age 52.4 years) were subjected to a descriptive analysis that yielded a definition of phases, determination of the peak angles reached, maximum angular velocity during each movement, and the sequencing of key events. While subjects showed little intrasubject variability, intersubject variability was evident. Subjects differed in the joint angles and angular velocity recorded, but the sequence of flexion/extension and rotation events were unchanged. Changes in direction of flexion/extension and rotation tended to occur very close in time, if not at the same time. Copyright © 1993. Published by Elsevier Ltd.

Presettlement Pinus taeda in the Mississippi Valley Alluvial Plain of the Monroe County, Arkansas area

Treesearch

Don C. Bragg

2005-01-01

Loblolly pine (Pinus taeda) is the most dominant conifer in the southeastern United States (Baker and Langdon, 1990). However, loblolly pine was conspicuously absent from virtually the entire Mississippi Valley Alluvial Plain during presettlement times. A map (Fig. 1) of the native distribution of loblolly from Baker and Langdon (1990) identifies 2 exceptions to this...

CANOPY CONDUCTANCE OF PINUS TAEDA, LIQUIDAMBAR STYRACIFLUA AND QUERCUS PHELLOS UNDER VARYING ATMOSPHERIC AND SOIL WATER CONDITION

EPA Science Inventory

Sap flow, and atmospheric and soil water data were collected in closed-top chambers under conditions of high soil water potential for saplings of Liquidambar styraciflua L., Quercus phellos L., and Pinus taeda L., three co-occurring species in the southeastern USA. Responses of c...

A primer on stand and forest inventory designs

Treesearch

H. Gyde Lund; Charles E. Thomas

1989-01-01

Covers designs for the inventory of stands and forests in detail and with worked-out examples. For stands, random sampling, line transects, ricochet plot, systematic sampling, single plot, cluster, subjective sampling and complete enumeration are discussed. For forests inventory, the main categories are subjective sampling, inventories without prior stand mapping,...

Functional groups show distinct differences in nitrogen cycling during early stand development: implications for forest management.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubrey, Doug, P.; Coyle, David, R. Coleman, Mark, D.

2011-08-26

Nutrient acquisition of forest stands is controlled by soil resource availability and belowground production, but tree species are rarely compared in this regard. Here, we examine ecological and management implications of nitrogen (N) dynamics during early forest stand development in productive commercial tree species with narrow (Populus deltoides Bartr. and Platanus occidentalis L.) and broad (Liquidambar styraciflua L. and Pinus taeda L.) site requirements while grown with a range of nutrient and water resources. We constructed N budgets by measuring N concentration ([N]) and N content (N{sub C}) of above- and belowground perennial and ephemeral tissues, determined N uptake (N{submore » UP}), and calculated N use efficiency (NUE). Forest stands regulated [N] within species-specific operating ranges without clear temporal or treatment patterns, thus demonstrating equilibrium between tissue [N] and biomass accumulation. Forest stand N{sub C} and N{sub UP} increased with stand development and paralleled treatment patterns of biomass accumulation, suggesting productivity is tightly linked to N{sub UP}. Inclusion of above- and belowground ephemeral tissue turnover in N{sub UP} calculations demonstrated that maximum N demand for narrow-sites adapted species exceeded 200 kg N ha{sup -1} year{sup -1} while demand for broad-site adapted species was below this level. NUE was species dependent but not consistently influenced by N availability, suggesting relationships between NUE and resource availability were species dependent. Based on early stand development, species with broad site adaptability are favored for woody cropping systems because they maintain high above- and belowground productivity with minimal fertilization requirements due to higher NUE than narrow site adapted species.« less

Monthly leaf area index estimates from point-in-time measurements and needle phenology for Pinus taeda

Treesearch

D.A. Sampson; T.J. Albaugh; Kurt H. Johnsen; H.L. Allen; Stanley J. Zarnoch

2003-01-01

Abstract: Leaf area index (LAI) of loblolly pine (Pinus taeda L.) trees of the southern United States varies almost twofold interannually; loblolly pine, essentially, carries two foliage cohorts at peak LAI (September) and one at minimum (March–April). Herein, we present an approach that may be site invariant to estimate monthly...

Atmospheric carbon dioxide, irrigation, and fertilization effects on phenolic and nitrogen concentrations in loblolly pine (Pinus taeda) needles

Treesearch

Fitzgerald L. Booker; Christopher A. Maier

2001-01-01

Concentrations of total soluble phenolics, catechin, proanthocyanidins (PA), lignin and nitrogen (N) were measured in loblolly pine (Pinus taeda L.) needles exposed to either ambient CO2 concentration ([CO2]), ambient plus 175 or ambient plus 350 µmol O2 mol-1 in branch chambers...

Correlation between infection by ophiostomatoid fungi and the presence of subterranean termites in Loblolly pine (Pinus taeda L.) roots

USDA-ARS?s Scientific Manuscript database

Observations of subterranean termites feeding in pine sapwood containing ophiostomatoid fungi prompted a study to investigate the effect of infection by Leptographium fungi on the probability of encountering subterranean termites in loblolly pine (Pinus taeda L.) roots. Root samples were collected f...

Efficacy of two insecticides for protecting loblolly pines (Pinus taeda L.) from subcortical beetles (Coleoptera: Curculionidae and Cerambycidae)

Treesearch

Jordon L. Burke; James L. Hanula; Scott Horn; Jackson P. Audley; Kamal JK. Gandhi

2012-01-01

Tests were conducted on two insecticides (carbaryl and bifenthrin) for excluding subcortical beetles (Coleoptera: Curculionidae and Cerambycidae) from loblolly pine trees (Pinus taeda L.). Two trap designs (single- and double-pane windows) and two trapping heights (1.5 and 4m) were also evaluated for maximizing beetle catches.

The effects of drought and disturbance on the growth and developmental instability of loblolly pine (Pinus taeda L.)

Treesearch

John H. Graham; Jeffrey J. Duda; Michelle L. Brown; Stanley Kitchen; John M. Emlen; Jagadish Malol; Elizabeth Bankstahl; Anthony J. Krzysik; Harold Balbach; D. Carl Freeman

2012-01-01

Ecological indicators provide early warning of adverse environmental change, helping land managers adaptively manage their resources while minimizing costly remediation. In 1999 and 2000, we studied two such indicators, growth and developmental instability, of loblolly pine (Pinus taeda L.) influenced by mechanized infantry training at Fort Benning, Georgia. Disturbed...

Wildfire mitigation strategies affect soil enzyme activity and soil organic carbon in loblolly pine (Pinus taeda) forests

Treesearch

R.E.J. Boerner; T.A. Waldrop; V.B. Shelburne

2006-01-01

We quantified the effects of three wildfire hazard reduction treatments (prescribed fire, thinning from below, and the combination of fire and thinning), and passive management (control) on mineral soil organic C, and enzyme activity in loblolly pine (Pinus taeda L.) forests on the Piedmont of South Carolina. Soil organic C was reduced by thinning,...

Nitrogen metabolism in Lignifying Pinus taeda cell cultures

NASA Technical Reports Server (NTRS)

van Heerden, P. S.; Towers, G. H.; Lewis, N. G.

1996-01-01

The primary metabolic fate of phyenylalanine, following its deamination in plants, is conscription of its carbon skeleton for lignin, suberin, flavonoid, and related metabolite formation. Since this accounts for approximately 30-40% of all organic carbon, an effective means of recycling the liberated ammonium ion must be operative. In order to establish how this occurs, the uptake and metabolism of various 15N-labeled precursors (15N-Phe, 15NH4Cl, 15N-Gln, and 15N-Glu) in lignifying Pinus taeda cell cultures was investigated, using a combination of high performance liquid chromatography, 15N NMR, and gas chromatograph-mass spectrometry analyses. It was found that the ammonium ion released during active phenylpropanoid metabolism was not made available for general amino acid/protein synthesis. Rather it was rapidly recycled back to regenerate phenylalanine, thereby providing an effective means of maintaining active phenylpropanoid metabolism with no additional nitrogen requirement. These results strongly suggest that, in lignifying cells, ammonium ion reassimilation is tightly compartmentalized.

Evaluation of a dynamic arm support for seated and standing tasks: a laboratory study of electromyography and subjective feedback.

PubMed

Odell, Dan; Barr, Alan; Goldberg, Robert; Chung, Jeffrey; Rempel, David

2007-04-01

The goal of this study was to determine whether a new dynamic arm support system reduced shoulder and arm muscle load for seated and standing hand/ arm tasks. The new system provides support for both horizontal and vertical arm motion. A total of 11 participants performed ten tasks (five seated and five standing) both with and without the arm support. Outcomes were assessed with electromyography and subjective feedback. Muscle activity was measured over the dominant side supraspinatus, triceps and forearm extensor muscles. Significant (p < 0.01) reductions in static muscle activity were observed in one of ten tasks performed with the support device for the supraspinatus muscle, in five tasks for the triceps and in one task for forearm extensor muscles. Likewise, a significant improvement in subjective measures was reported with the support device for 'ease of task' for two of ten tasks, for 'forearm comfort' for three of ten tasks and for 'shoulder effort' for six of ten tasks. The results suggest that a dynamic forearm support may improve subjective comfort and reduce static muscle loads in the upper extremity for tasks that involve horizontal movement of the arms. For rapid motions, the value of the support is limited due to internal inertia and friction.

Water and Energy Balances of Loblolly Pine Plantation Forests during a Full Stand Rotation

NASA Astrophysics Data System (ADS)

Sun, G.; Mitra, B.; Domec, J. C.; Gavazi, M.; Yang, Y.; Tian, S.; Zietlow, D.; McNulty, S.; King, J.; Noormets, A.

2017-12-01

Loblolly pine (Pinus taeda) plantations in the southern U.S. are well recognized for their ecosystem services in supplying clean and stable water and mitigating climate change through carbon sequestration and solar energy partitioning. Since 2004, we have monitored energy, water, and carbon fluxes in a chronosequence of three drained loblolly pine plantations using integrated methods that include eddy covariance, sap flux, watershed hydrometeorology, remote sensing, and process-based simulation modeling. Study sites were located on the eastern North Carolina coastal plain, representing highly productive ecosystems with high groundwater table, and designated in the Ameriflux network as NC1 (0-10 year old), NC2 (12-25 year old) and NC3 (0-3 years old). The 13-year study spanned a wide range of annual precipitation (900-1600 mm/yr) including two exceptionally dry years during 2007-2008. We found that the mature stand (NC2) had higher net radiation (Rn) flux due to its lower albedo (α =0.11-12), compared with the young stands (NC1, NC3) (α=0.15-0.18). Annually about 75%-80% of net radiation was converted to latent heat in the pine plantations. In general, the mature stand had higher latent heat flux (LE) (i.e. evapotranspiration (ET)) rates than the young stands, but ET rates were similar during wet years when the groundwater table was at or near the soil surface. During a historic drought period (i.e., 2007-2008), total stand annual ET exceeded precipitation, but decreased about 30% at NC2 when compared to a normal year (e.g., 2006). Field measurements and remote sensing-based modeling suggested that annual ET rates increased linearly from planting age (about 800 mm) to age 15 (about 1050 mm) and then stabilized as stand leaf area index leveled-off. Over a full stand rotation, approximately 70% (young stand) to 90% (mature stand) of precipitation was returned to the atmosphere through ET. We conclude that both climatic variability and canopy structure controlled the

The effects of upper and lower limb position on symmetry of vertical ground reaction force during sit-to-stand in chronic stroke subjects

PubMed Central

Lee, Jae Hong; Min, Dong Ki; Choe, Han Seong; Lee, Jin Hwan; Shin, So Hong

2018-01-01

[Purpose] The purpose of this study was to evaluate the influence of arm and leg posture elements on symmetrical weight bearing during Sit to Stand tasks in chronic stroke patients. [Subjects and Methods] The subjects were diagnosed with stroke and 22 patients (15 males and 7 females) participated in this study. All participants performed Sit to Stand tasks on three foot postures and two arm postures. Two force plates were used to measure peak of vertical ground reaction force and symmetrical ratio to peak Fz. The data were analyzed using independent t-test and two-way repeated ANOVA. [Results] The results of this study are as follows: 1) Peak Fz placed more weight in non-paretic leg during Sit to Stand. 2) A symmetrical ratio to Peak Fz indicated significant difference between foot and arm posture, and had non-paretic limb supported on a step and paretic at ground level (STP) and grasped arm posture that lock fingers together with shoulder flexion by 90°(GA) (0.79 ± 0.09). [Conclusion] These results suggest that STP posture of the legs and GA posture of the arms should be able to increase the use of the paretic side during Sit to Stand behavior and induce normal Sit to Stand mechanism through the anterior tilt of the hip in clinical practices, by which loads onto the knee joint and the ankle joint can be reduced, and the trunk righting response can be promoted by making the back fully stretched. The outcome of this study is expected to be a reference for exercise or prognosis of Sit to Stand in stroke patients. PMID:29545686

Canopy Level Emissions of 2-methyl-3-buten-2-ol, monoterpenes, and sesquiterpenes from a Pinus taeda Experimental Plantation

EPA Science Inventory

Emissions of biogenic volatile organic compounds (BVOC) observed during 2007 from a Pinus taeda experimental plantation in Central North Carolina are compared with model estimates from MEGAN 2.1. Relaxed Eddy Accumulation (REA) estimates of 2-methyl-3-buten-2-ol (MBO) fluxes are ...

An 8-year field comparison of naturally seeded to planted container Pinus taeda, with and without release

Treesearch

Michael D. Cain; James P. Barnett

1996-01-01

Abstract:A field study compared genetically improved, container loblolly pines (Pinus taeda L.) with naturally seeded loblolly pines through eight growing seasons on a cutover site in southern Arkansas, U.S.A. Measurement pines on 6 of 12 plots were released from woody and herbaceous competition within a 61-cm radius of each tree stem. On natural...

Heterologous Array Analysis in Pinaceae: Hybridization of Pinus Taeda cDNA Arrays With cDNA From Needles and Embryogenic Cultures of P. Taeda, P. Sylvestris or Picea Abies

PubMed Central

van Zyl, Leonel; von Arnold, Sara; Bozhkov, Peter; Chen, Yongzhong; Egertsdotter, Ulrika; MacKay, John; Sederoff, Ronald R.; Shen, Jing; Zelena, Lyubov

2002-01-01

Hybridization of labelled cDNA from various cell types with high-density arrays of expressed sequence tags is a powerful technique for investigating gene expression. Few conifer cDNA libraries have been sequenced. Because of the high level of sequence conservation between Pinus and Picea we have investigated the use of arrays from one genus for studies of gene expression in the other. The partial cDNAs from 384 identifiable genes expressed in differentiating xylem of Pinus taeda were printed on nylon membranes in randomized replicates. These were hybridized with labelled cDNA from needles or embryogenic cultures of Pinus taeda, P. sylvestris and Picea abies, and with labelled cDNA from leaves of Nicotiana tabacum. The Spearman correlation of gene expression for pairs of conifer species was high for needles (r2 = 0.78 − 0.86), and somewhat lower for embryogenic cultures (r2 = 0.68 − 0.83). The correlation of gene expression for tobacco leaves and needles of each of the three conifer species was lower but sufficiently high (r2 = 0.52 − 0.63) to suggest that many partial gene sequences are conserved in angiosperms and gymnosperms. Heterologous probing was further used to identify tissue-specific gene expression over species boundaries. To evaluate the significance of differences in gene expression, conventional parametric tests were compared with permutation tests after four methods of normalization. Permutation tests after Z-normalization provide the highest degree of discrimination but may enhance the probability of type I errors. It is concluded that arrays of cDNA from loblolly pine are useful for studies of gene expression in other pines or spruces. PMID:18629264

Standing Vs Supine; Does it Matter in Cough Stress Testing?

PubMed

Patnam, Radhika; Edenfield, Autumn L; Swift, Steven E

The aim of this study was to compare the sensitivity of cough stress test in the standing versus supine position in the evaluation of incontinent females. We performed a prospective observational study of women with the chief complaint of urinary incontinence (UI) undergoing a provocative cough stress test (CST). Subjects underwent both a standing and a supine CST. Testing order was randomized via block randomization. Cough stress test was performed in a standard method via backfill of 200 mL or until the subject described strong urge. The subjects were asked to cough, and the physician documented urine leakage by direct observation. The gold standard for stress UI diagnosis was a positive CST in either position. Sixty subjects were enrolled, 38 (63%) tested positive on any CST, with 38 (63%) positive on standing compared with 29 (28%) positive on supine testing. Nine women (15%) had positive standing and negative supine testing. No subjects had negative standing with positive supine testing. There were no significant differences in positive tests between the 2 randomized groups (standing first and supine second vs. supine first and standing second). When compared with the gold standard of any positive provocative stress test, the supine CST has a sensitivity of 76%, whereas the standing CST has a sensitivity of 100%. The standing CST is more sensitive than the supine CST and should be performed in any patient with a complaint of UI and negative supine CST. The order of testing either supine or standing first does not affect the results.

Vascular cambial sucrose metabolism and growth in loblolly pine (Pinus taeda L.) in relation to transplanting stress

Treesearch

Shi-Jean S. Sung; Paul P. Kormanik; C.C. Black

1993-01-01

Sucrose synthase (SS) was the dominant enzyme of sucrose metabolism in both stem and root vascular cambial zone tissues of nursery-grown loblolly pine (Pinus taeda L.) seedlings.Acid invertase (AI) and neutral invertase (NI) activties were generally less than 10% of the SS activity in both tissues.In both cambial tissues, seasonal patterns of SS activity in stem and...

Taking a Stand: The Effects of Standing Desks on Task Performance and Engagement

PubMed Central

Tomiyama, A. Janet; Ward, Andrew

2017-01-01

Time spent sitting is associated with negative health outcomes, motivating some individuals to adopt standing desk workstations. This study represents the first investigation of the effects of standing desk use on reading comprehension and creativity. In a counterbalanced, within-subjects design, 96 participants completed reading comprehension and creativity tasks while both sitting and standing. Participants self-reported their mood during the tasks and also responded to measures of expended effort and task difficulty. In addition, participants indicated whether they expected that they would perform better on work-relevant tasks while sitting or standing. Despite participants’ beliefs that they would perform worse on most tasks while standing, body position did not affect reading comprehension or creativity performance, nor did it affect perceptions of effort or difficulty. Mood was also unaffected by position, with a few exceptions: Participants exhibited greater task engagement (i.e., interest, enthusiasm, and alertness) and less comfort while standing rather than sitting. In sum, performance and psychological experience as related to task completion were nearly entirely uninfluenced by acute (~30-min) standing desk use. PMID:28825655

Comparison of erector spinae and hamstring muscle activities and lumbar motion during standing knee flexion in subjects with and without lumbar extension rotation syndrome.

PubMed

Kim, Si-hyun; Kwon, Oh-yun; Park, Kyue-nam; Kim, Moon-Hwan

2013-12-01

The aim of this study was to compare the activity of the erector spinae (ES) and hamstring muscles and the amount and onset of lumbar motion during standing knee flexion between individuals with and without lumbar extension rotation syndrome. Sixteen subjects with lumbar extension rotation syndrome (10 males, 6 females) and 14 healthy subjects (8 males, 6 females) participated in this study. During the standing knee flexion, surface electromyography (EMG) was used to measure muscle activity, and surface EMG electrodes were attached to both the ES and hamstring (medial and lateral) muscles. A three-dimensional motion analysis system was used to measure kinematic data of the lumbar spine. An independent-t test was conducted for the statistical analysis. The group suffering from lumbar extension rotation syndrome exhibited asymmetric muscle activation of the ES and decreased hamstring activity. Additionally, the group with lumbar extension rotation syndrome showed greater and earlier lumbar extension and rotation during standing knee flexion compared to the control group. These data suggest that asymmetric ES muscle activation and a greater amount of and earlier lumbar motion in the sagittal and transverse plane during standing knee flexion may be an important factor contributing to low back pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of low back pain on the kinematics and joint coordination of the lumbar spine and hip during sit-to-stand and stand-to-sit.

PubMed

Shum, Gary L K; Crosbie, Jack; Lee, Raymond Y W

2005-09-01

Experimental study to describe lumbar spine and hip joint movements during sit-to-stand and stand-to-sit. To examine differences in the kinematics and joint coordination of the lumbar spine and hips during sit-to-stand and stand-to-sit between healthy subjects and patients with subacute low back pain (LBP). There is a paucity of information on the coordination of movements of lumbar spine and hips during sit-to-stand and stand-to-sit. The effect of LBP, with or without nerve root signs, is largely unknown. A three-dimensional real-time electromagnetic tracking device was used to measure movements of the lumbar spine and hips during sit-to-stand and stand-to-sit. Sixty subacute LBP participants with or without straight leg raise signs and 20 healthy asymptomatic participants were recruited. The kinematic patterns of lumbar spine and hips were analyzed. Coordination between the two joints was studied by relative phase angle analysis. The mobility of the spine and hips was significantly limited in back pain subjects. It was observed that LBP subjects employed various strategies to compensate for the limited motions at the hips and lumbar spine. The contribution of the lumbar spine relative to that of the hip was found to be reduced for subjects with LBP. The lumbar spine-hip joint coordination was significantly altered in back pain subjects, in particular, those with positive straight leg raise sign. Back pain was related to changes in the kinematics and coordination of the lumbar spine and hips during sit-to-stand and stand-to-sit. Assessment of back pain patients should include kinematic analysis of the hips as well as the spine.

Effects of stand and site variables on the lumber value of uneven-aged loblolly pine stands

Treesearch

David W. Patterson; Paul A. Murphy; Michael G. Shelton

2000-01-01

Uneven-aged silviculture using single-tree selection provides the landowner with periodic income from a continuous forest which has a varied canopy. Data were collected from 24 plots of a larger study to determine if site index, basal area, and maximum dbh affected volume and value of lumber from loblolly pine (Pinus taeda L.) trees in uneven-aged...

Small mammal distributions relative to corridor edges within intensively managed southern pine plantations.

Treesearch

Nicole L. Constantine; Tyler A. Campbell; William M. Baughman; Timothy B. Harrington; Brian R. Chapman; Karl V. Miller

2005-01-01

We characterized small mammal communities in three loblolly pine (Pinus taeda) stands in the Lower Coastal Plain of South Carolina during June 1998-Aug. 2000 to investigate influence of corridor edges on small mammal distribution. We live-trapped small mammals in three regenerating stands following clearcutting. Harvested stands were bisected by...

Seasonal Photosynthesis in Fertilized and Nonfertilized Loblolly Pine

Treesearch

Christopher M. Gough; John R. Seiler; Kurt H. Johnsen; David Arthur Sampson

2004-01-01

Net photosynthesis (Pn) of loblolly pine (Pinus taeda L.) foliage was monitored monthly in 14 yr old stands under near-ambient conditions over an entire year in upper and lower crowns and in both nonfertilized stands and stands receiving nutrient amendments for six consecutive years. Air temperature, humidity, vapor pressure...

Best Protocol for the Sit-to-Stand Test in Subjects With COPD.

PubMed

Morita, Andrea A; Bisca, Gianna W; Machado, Felipe V C; Hernandes, Nidia A; Pitta, Fabio; Probst, Vanessa S

2018-05-22

Different protocols for the sit-to-stand test (STS) are available for assessing functional capacity in COPD. We sought to correlate each protocol of the STS (ie, the 5-repetition [5-rep STS], the 30-s STS, and the 1-min STS) with clinical outcomes in subjects with COPD. We also aimed to compare the 3 protocols of the STS, to verify their association and agreement, and to verify whether the 3 protocols are able to predict functional exercise capacity and physical activity in daily life (PADL). 23 subjects with COPD (11 men; FEV 1 53 ± 15% predicted) performed 3 protocols of the STS. Subjects also underwent the following assessments: incremental shuttle walking test, 6-min walk test (6MWT), 4-m gait speed test (4MGS), 1-repetition maximum of quadriceps muscle, assessment of PADL, and questionnaires on health-related quality of life and functional status. The 1-min STS showed significant correlations with the 6MWT (r = 0.40), 4MGS (r = 0.64), and PADL (0.40 ≤ r ≤ 0.52), and the 5-rep STS and 30-s STS were associated with the 4MGS (r = 0.54 and r = 0.52, respectively). The speed differed for each protocol (5-rep STS 0.53 ± 0.16 rep/s, 30-s STS 0.48 ± 0.13 rep/s, 1-min STS 0.45 ± 0.11 rep/s, P = .01). However, they presented good agreement (intraclass correlation coefficient ≥ 0.73 for all) and correlated well with each other (r ≥ 0.68 for all). More marked changes in peripheral oxygen saturation ( P = .004), heart rate ( P < .001), blood pressure ( P < .001), dyspnea ( P < .001), and leg fatigue ( P < .001) were found after the 1-min STS protocol. Furthermore, the 3 protocols were equally able to identify subjects with low exercise capacity or preserved exercise capacity. The 1-min STS generated higher hemodynamic demands and correlated better with clinical outcomes in subjects with COPD. Despite the difference in speed performance and physiological demands between the 5-rep STS and 1-min STS, there was a good level of agreement among the 3 protocols. In

Association genetics of growth and adaptive traits in loblolly pine (Pinus taeda L.) using whole-exome-discovered polymorphisms

Treesearch

Mengmeng Lu; Konstantin V. Krutovsky; C. Dana Nelson; Jason B. West; Nathalie A. Reilly; Carol A. Loopstra

2017-01-01

In the USA, forest genetics research began over 100 years ago and loblolly pine breeding programs were established in the 1950s. However, the genetics underlying complex traits of loblolly pine remains to be discovered. To address this, adaptive and growth traits were measured and analyzed in a clonally tested loblolly pine (Pinus taeda L.) population. Over 2.8 million...

Modeling the longitudinal variation in wood specific gravity of planted loblolly pine (Pinus taeda) in the United States

Treesearch

F. Antony; L. R. Schimleck; R. F. Daniels; Alexander Clark; D. B. Hall

2010-01-01

Loblolly pine (Pinus taeda L.) is a major plantation species grown in the southern United States, producing wood having a multitude of uses including pulp and lumber production. Specific gravity (SG) is an important property used to measure the quality of wood produced, and it varies regionally and within the tree with height and radius. SG at different height levels...

Individual-tree Green Weight Equations for Loblolly Pine (Pinus taeda L.) Sawtimber in the Coastal Plain of Arkansas

Treesearch

Travis E. Posey; Paul F. Doruska; David W. Patterson

2005-01-01

Loblolly pine (Pinus taeda L.) weight equations were developed to predict outside-bark, green bole weight to a 4-inch diameter-inside-bark (dib) top and an 8-inch dib top in southeast Arkansas. Trees were sampled from 8 different tracts over the first half of 2002: 4 tracts during winter and spring, respectively. The sampled trees ranged from 10 to...

Influence of hardwood midstory and pine species on pine bole arthropods

Treesearch

Christopher S. Collins; Richard N. Conner; Daniel Saenz

2002-01-01

Arthropod density on the boles of loblolly pines (Pinus taeda) was compared between a stand with and stand without hardwood midstory and between a stand of loblolly and shortleaf pines (P. echinata) in the Stephen E Austin Experimental Forest, Nacogdoches Co., Texas, USA from September 1993 through July 1994. Arthropod density was...

Propiedades del suelo y sus relaciones con el IS en plantaciones de Pinus taeda L. en la Mesopotamia Argentina

Treesearch

Rodolfo A. Martiarena; Jorge L. Frangi; Alejandra Von Wallis; Marcelo F. Arturi; Hugo E. Fassola; Roberto A. Fernandez

2014-01-01

This paper was aimed at establishing the relations between some soil properties and the growth of P. taeda on its main area of commercial plantation in Argentine Mesopotamia. It was hypothesized that main cause of productivity reduction is soil depth and effective plant- available soil volume rather than nutrient content. The study area was located in Corrientes and...

The effect of a hybrid assistive limb® on sit-to-stand and standing patterns of stroke patients

PubMed Central

Kasai, Rie; Takeda, Sunao

2016-01-01

[Purpose] The Hybrid Assistive Limb® (HAL®) robot suit is a powered exoskeleton that can assist a user’s lower limb movement. The purpose of this study was to assess the effectiveness of HAL® in stroke rehabilitation, focusing on the change of the sit-to-stand (STS) movement pattern and standing posture. [Subjects and Methods] Five stroke patients participated in this study. Single leg HAL® was attached to each subject’s paretic lower limb. The subjects performed STS three times both with and without HAL® use. A tri-axial accelerometer was used to assess the STS movement pattern. Forward-tilt angle (FTA) and the time required for STS were measured with and without HAL® use. Surface electromyography (EMG) of STS and standing were recorded to assess the vastus medialis muscle activities of the paretic limb. [Results] The average FTA without HAL® use was 35° and it improved to 43° with HAL® use. The time required for STS was longer for all subjects with HAL® use (without HAL® use: 3.42 s, with HAL® use: 5.11 s). The integrated EMGs of HAL® use compared to those without HAL®, were 83.6% and 66.3% for STS and standing, respectively. [Conclusion] HAL® may be effective in improving STS and standing patterns of stroke patients. PMID:27390416

TEST STAND 4697 CONSTRUCTION

NASA Image and Video Library

2016-01-06

A CRANE MOVES THE FIRST STEEL TIER TO BE BOLTED INTO PLACE ON JAN. 6, FOR WELDING OF A SECOND NEW STRUCTURAL TEST STAND AT NASA'S MARSHALL SPACE FLIGHT CENTER IN HUNTSVILLE, ALABAMA -- CRITICAL TO DEVELOPMENT OF NASA'S SPACE LAUNCH SYSTEM. WHEN COMPLETED THIS SUMMER, THE 85-FOOT-TALL TEST STAND 4697 WILL USE HYDRAULIC CYLINDERS TO SUBJECT THE LIQUID OXYGEN TANK AND HARDWARE OF THE MASSIVE SLS CORE STAGE TO THE SAME LOADS AND STRESSES IT WILL ENDURE DURING A LAUNCH. THE STAND IS RISING IN MARSHALL'S WEST TEST AREA, WHERE WORK IS ALSO UNDERWAY ON THE 215-FOOT-TALL TOWERS OF TEST STAND 4693, WHICH WILL CONDUCT SIMILAR STRUCTURAL TESTS ON THE SLS CORE STAGE'S LIQUID HYDROGEN TANK. SLS, THE MOST POWERFUL ROCKET EVER BUILT, WILL CARRY ASTRONAUTS IN NASA'S ORION SPACECRAFT ON DEEP SPACE MISSIONS, INCLUDING THE JOURNEY TO MARS.

Using silvicultural practices to regulate competition, resource availability, and growing conditions for Pinus palustris seedlings underplanted in Pinus taeda forests

Treesearch

Benjamin O. Knapp; G. Geoff Wang; Joan L. Walker; Huifeng Hu

2016-01-01

In the southeastern United States, many forest managers are interested in restoring longleaf pine (Pinus palustris Mill.) to upland sites that currently support loblolly pine (Pinus taeda L.). We quantified the effects of four canopy treatments (uncut Control; MedBA, harvest to 9 m2·ha−1...

Root system structure in planted and seeded loblolly and shortleaf pine

Treesearch

Constance A. Harrington; John C. Brissette; William C. Carlson

1989-01-01

Differences in root system structure attributable to stand origin were examined by pairing seeded and planted stands of loblolly (Pinus taeda L.) and shortleaf pine (P. echinata Mill.). The 17 paired stands were 3 to 9 years old and located in Arkansas, Oklahoma, and Texas on similar soil and site conditions. Root systems from 12...

Effects of temperature and tissue nitrogen on dormant season stem and branch maintenance respiration in a young loblolly pine (Pinus taeda) plantation

Treesearch

Chris A. Maier; Stanley J. Zarnoch; P.M. Dougherty

1998-01-01

Summary We measured dormant season (November through February) maintenance respiration rates (Rm) in stems and branches of 9-year-old loblolly pine (Pinus taeda L.) growing in plots under conditions of controlled nutrient and water supply in an effort to determine the relationships between Rm...

Near infrared spectroscopy for the nondestructive estimation of clear wood properties of Pinus taeda L. from the southern United States

Treesearch

Laurence R. Schimleck; P. David Jones; Alexander Clark; Richard F. Daniels; Gary F. Peter

2005-01-01

The estimation of specific gravity (SG), modulus of elasticity (MOE), and modulus of rupture (MOR) of loblolly pine (Pinus taeda L.) clear wood samples from a diverse range of sites across the southern United States was investigated using near infrared (NIR) spectroscopy. NIR spectra were obtained from the radial and cross sectional (original, rough...

The Subjective Postural Vertical Determined in Patients with Pusher Behavior During Standing.

PubMed

Bergmann, Jeannine; Krewer, Carmen; Selge, Charlotte; Müller, Friedemann; Jahn, Klaus

2016-06-01

The subjective postural vertical (SPV), i.e., the perceived upright orientation of the body in relation to gravity, is disturbed in patients with pusher behavior. So far, the SPV has been measured only when these patients were sitting, and the results were contradictory as regards the side of the SPV deviation. The objective was to investigate the SPV in patients with different degrees of severity of pusher behavior while standing. Eight stroke patients with pusher behavior, ten age-matched stroke patients without pusher behavior, and ten age-matched healthy control subjects were included. The SPV (SPV error, SPV range) was assessed in the pitch and the roll planes. Pusher behavior was classified with the Burke Lateropulsion Scale (BLS). In the pitch plane, the SPV range was significantly larger in pusher patients than in patients without pusher behavior or healthy controls. The SPV error was similar for groups. In the roll plane, the SPV error and the SPV range were significantly larger and more ipsilesionally tilted in the pusher group than in the other two groups. There was a significant correlation between the SPV error in the roll plane and the BLS score. The study revealed that patients with pusher behavior had an ipsilesional SPV tilt that decreased with decreasing severity of the behavior. The large uncertainty in verticality estimation in both planes indicates that their sensitivity for the perception of verticality in space is generally disturbed. These findings emphasize the importance of specific rehabilitation approaches to recalibrate the impaired inner model of verticality.

Pinus taeda forest growth predictions in the 21st century vary with site mean annual temperature and site quality.

PubMed

Gonzalez-Benecke, Carlos A; Teskey, Robert O; Dinon-Aldridge, Heather; Martin, Timothy A

2017-11-01

Climate projections from 20 downscaled global climate models (GCMs) were used with the 3-PG model to predict the future productivity and water use of planted loblolly pine (Pinus taeda) growing across the southeastern United States. Predictions were made using Representative Concentration Pathways (RCP) 4.5 and 8.5. These represent scenarios in which total radiative forcing stabilizes before 2100 (RCP 4.5) or continues increasing throughout the century (RCP 8.5). Thirty-six sites evenly distributed across the native range of the species were used in the analysis. These sites represent a range in current mean annual temperature (14.9-21.6°C) and precipitation (1,120-1,680 mm/year). The site index of each site, which is a measure of growth potential, was varied to represent different levels of management. The 3-PG model predicted that aboveground biomass growth and net primary productivity will increase by 10%-40% in many parts of the region in the future. At cooler sites, the relative growth increase was greater than at warmer sites. By running the model with the baseline [CO 2 ] or the anticipated elevated [CO 2 ], the effect of CO 2 on growth was separated from that of other climate factors. The growth increase at warmer sites was due almost entirely to elevated [CO 2 ]. The growth increase at cooler sites was due to a combination of elevated [CO 2 ] and increased air temperature. Low site index stands had a greater relative increase in growth under the climate change scenarios than those with a high site index. Water use increased in proportion to increases in leaf area and productivity but precipitation was still adequate, based on the downscaled GCM climate projections. We conclude that an increase in productivity can be expected for a large majority of the planted loblolly pine stands in the southeastern United States during this century. © 2017 John Wiley & Sons Ltd.

Soil CO2 evolution and root respiration in 11 year-old Loblolly Pine (Pinus taeda) Plantations as Affected by Moisture and Nutrient Availability

Treesearch

Chris A. Maier; L.W. Kress

2000-01-01

We measured soil CO2 evolution rates with (Sff) and without (Sms) the forest floor litter and root respiration monthly in 11-year-old loblolly pine (Pinus taeda L.) plantations during the fourth year of fertilization and irrigation treatments. Values of Sff...

Effect of foot placements during sit to stand transition on timed up and go test in stroke subjects: A cross sectional study.

PubMed

Joshua, Abraham M; Karnad, Shreekanth D; Nayak, Akshatha; Suresh, B V; Mithra, Prasanna; Unnikrishnan, B

2017-01-01

Timed up and go (TUG) test is been used as a screening tool for the assessment of risk of falling in individuals following stroke. Though TUG test is a quick test, it has fair sensitivity compared to other tests. This study was carried out to obtain and compare test scores for different types of foot placements during sit to stand transition in stroke subjects. A Cross-sectional study with purposive sampling included 28 post stroke subjects who were able to walk 6 meter with or without assistance. Timed Up and Go test was carried out with four different types of foot placements and scores were recorded. The data were compared using Kruskal-Wallis One way analysis of variance and Wilcoxon signed ranks test. There were comparable differences between asymmetric 1 test strategy which involved affected extremity to be placed behind the unaffected and other test strategies (Z = -4.457,-3.848,-4.458; p = 0.000). The initial foot placements during sit to stand transition influenced the time taken to complete the test which was significantly higher in asymmetric 1 strategy, Incorporation of the initial foot placement mainly asymmetric 1 strategy into conventional TUG test would help in identifying accurately the subject's functional mobility and postural stability.

Long-Term Trends in Productivity and Stand Characteristics Following Thinning of a Loblolly Pine Stand in S.E. Oklahoma

Treesearch

T. Hennessey; P. Dougherty; R. Wittwer; T. Lynch; A. Clark; E. Lorenzi; R. Heinemann; R. Holeman

2002-01-01

A thinning levels study was initiated in Southeastern Oklahoma in the spring of 1984. The study was installed in a 9 year-old loblolly pine (Pinus taeda L.) plantation that contained 110 ft2/ac of basal area. Thinning treatments consisted of (1) three control plots (BA-100) that were never thinned and contained an average of...

The effects of decreased water availability on loblolly pine (Pinus taeda L.) productivity and the interaction between fertilizer and drought

Treesearch

Adam O. Maggard; Rodney E. Will; Duncan S. Wilson; Cassandra R. Meek

2016-01-01

As part of the regional PINEMAP (Pine Integrated Network: Education, Mitigation, and Adaptation project) funded by the NIFA - USDA, we established a factorial study in McCurtain County, OK near Broken Bow. This study examined the effects of fertilization and ~30 percent reduction in throughfall on an seven-yearold loblolly pine (Pinus taeda L.) plantation. The...

Modified water regimes affect photosynthesis, xylem water potential, cambial growth and resistance of juvenile Pinus taeda L. to Dendroctonus frontalis (Coleoptera: Scolytidae)

Treesearch

James P. Dunn; Peter L. Jr. Lorio

1993-01-01

We modified soil water supply to two groups of juvenile loblolly pines, Pinus taeda L., by sheltering or irrigating root systems in early summer or in later summer and measured oleoresin flow (primary defense), net photosynthesis, xylem water potential, and cambial growth throughout the growing season. When consistent significant differences in...

Structural characteristics of late-sucessional pine-hardwood forest following recent infestation by southern pine beetle in the Georgia Piedmont, USA

Treesearch

Timothy B. Harrington; Mingguang Xu; M. Boyd Edwards

2000-01-01

At Murder Creek Research Natural Area, Georgia, USA, we compared structural characteristics of late-successional pine-hardwood stands two to three years after infestation by southern pine beetle (Dendroctonus frontalis Zimmerman) to those of adjacent noninfested stands. Death of up to eight Pinus taeda L. and P. echinata...

Isolation of 4-coumarate Co-A ligase gene promoter from loblolly pine (Pinus taeda) and characterization of tissue-specific activity in transgenic tobacco.

PubMed

Osakabe, Yuriko; Osakabe, Keishi; Chiang, Vincent L

2009-01-01

We characterized promoter activity of a phenylpropanoid biosynthetic gene encoding 4-coumarate Co-A ligase (4CL), Pta4Clalpha, from Pinus taeda. Histochemical- and quantitative assays of GUS expression in the vascular tissue were performed using transgenic tobacco plants expressing promoter-GUS reporters. Deletion analysis of the Pta4Clalpha promoter showed that the region -524 to -252, which has two AC elements, controls the high expression levels in ray-parenchyma cells of older tobacco stems. High activity level of the promoter domain of Pta4CLalpha was also detected in the xylem cells under bending stress. DNA-protein complexes were detected in the reactions of the Pta4CLalpha promoter fragments with the nuclear proteins of xylem of P. taeda. The AC elements in the Pta4CLalpha promoter appeared to have individual roles during xylem development that are activated in a coordinated manner in response to stress in transgenic tobacco.

Species composition, size structure, and disturbance: History of an old growth bottomland hardwood loblolly pine (Pinus taeda) forest in Arkansas, USA

Treesearch

Eric Heitzman; Michael G. Shelton; Adrian Grell

2004-01-01

The Lost Forty is a 16-ha old-growth bottomland hardwood-lobtolly pine (Pinus taeda L.) forest iocated in south-central Arkansas that has had little human disturbance. We established plots in the Lost Forty and collected data on species composition, tree size, age structure, and radial stem growth patterns. The overstory was dominated by species that...

Modal Damping Ratio and Optimal Elastic Moduli of Human Body Segments for Anthropometric Vibratory Model of Standing Subjects.

PubMed

Gupta, Manoj; Gupta, T C

2017-10-01

The present study aims to accurately estimate inertial, physical, and dynamic parameters of human body vibratory model consistent with physical structure of the human body that also replicates its dynamic response. A 13 degree-of-freedom (DOF) lumped parameter model for standing person subjected to support excitation is established. Model parameters are determined from anthropometric measurements, uniform mass density, elastic modulus of individual body segments, and modal damping ratios. Elastic moduli of ellipsoidal body segments are initially estimated by comparing stiffness of spring elements, calculated from a detailed scheme, and values available in literature for same. These values are further optimized by minimizing difference between theoretically calculated platform-to-head transmissibility ratio (TR) and experimental measurements. Modal damping ratios are estimated from experimental transmissibility response using two dominant peaks in the frequency range of 0-25 Hz. From comparison between dynamic response determined form modal analysis and experimental results, a set of elastic moduli for different segments of human body and a novel scheme to determine modal damping ratios from TR plots, are established. Acceptable match between transmissibility values calculated from the vibratory model and experimental measurements for 50th percentile U.S. male, except at very low frequencies, establishes the human body model developed. Also, reasonable agreement obtained between theoretical response curve and experimental response envelop for average Indian male, affirms the technique used for constructing vibratory model of a standing person. Present work attempts to develop effective technique for constructing subject specific damped vibratory model based on its physical measurements.

Branch growth and gas exchange in 13-year-old loblolly pine (Pinus taeda) trees in response to elevated carbon dioxide concentration and fertilization

Treesearch

Chris A. Maier; Kurt H. Johnsen; John Butnor; Lance W. Kress; Peter H. Anderson

2002-01-01

Summary We used whole-tree, open-top chambers to expose 13-year-old loblolly pine (Pinus taeda L.) trees, growing in soil with high or low nutrient availability, to either ambient or elevated (ambient + 200 µmol mol-1 ) carbon dioxide concentration ([CO2]) for 28 months. Branch growth...

The influence of thermoplastic thoraco lumbo sacral orthoses on standing balance in subjects with idiopathic scoliosis.

PubMed

Khanal, Minoo; Arazpour, Mokhtar; Bahramizadeh, Mahmood; Samadian, Mohammad; Hutchins, Stephen W; Kashani, Reza Vahab; Mardani, Mohammad A; Tari, Hossein Vahid; Aboutorabi, Atefeh; Curran, Sarah; Sadeghi, Heidar

2016-08-01

Idiopathic scoliosis patients have postural equilibrium problems. The objective of this study was to assess postural control in subjects with idiopathic scoliosis following a 4-month intervention in an unbraced position. Quasi-experimental. Eight healthy girls and eight girls with idiopathic scoliosis took part. A Kistler force platform was used with a frequency of 100 Hz for recording data. The center of pressure was recorded in different positions out of brace for scoliosis and healthy subjects. Test conditions were single limb and double limb stance, with eyes open and closed, and foam and rigid surfaces. The data reflected a weak balance of idiopathic scoliosis subjects compared to healthy subjects. After 1 and 4 months of wearing the brace, center of pressure and center of gravity sway increased in the majority of the tests, although there were no significant differences in any of the test conditions (p > 0.05). While the center of pressure sway in medio-lateral direction decreased after 4 months of wearing a brace, in other variables center of pressure and center of gravity sway increased. Idiopathic scoliosis patients have weak balance in comparison to healthy subjects. In addition, following a period of 4 months of wearing a brace, balance parameters in the scoliosis subjects did not improve. The results show that we need more follow-up of orthoses wearing in idiopathic scoliosis subjects and suggest more studies at least 1-year follow-up to identify the efficiency of brace wear on balance. Scoliosis can alter postural stability and balance performance during quiet standing. Spinal deformity can alter a subject's ability to compensate for postural changes and cause gait deviations. This study investigated balance differences between the healthy and idiopathic scoliosis patients and the results of thoraco lumbo sacral orthosis brace wear. It might provide some new insight into the conservative treatment of idiopathic scoliosis patients for

Genetic effects on total phenolics, condensed tannins and non-structural carbohydrates in loblolly pine (Pinus taeda L.) needles.

PubMed

Aspinwall, Michael J; King, John S; Booker, Fitzgerald L; McKeand, Steven E

2011-08-01

Carbon allocation to soluble phenolics (total phenolics, proanthocyanidins (PA)) and total non-structural carbohydrates (TNC; starch and soluble sugars) in needles of widely planted, highly productive loblolly pine (Pinus taeda L.) genotypes could impact stand resistance to herbivory, and biogeochemical cycling in the southeastern USA. However, genetic and growth-related effects on loblolly pine needle chemistry are not well characterized. Therefore, we investigated genetic and growth-related effects on foliar concentrations of total phenolics, PA and TNC in two different field studies. The first study contained nine different genotypes representing a range of genetic homogeneity, growing in a 2-year-old plantation on the coastal plain of North Carolina (NC), USA. The second study contained eight clones with different growth potentials planted in a 9-year-old clonal trial replicated at two sites (Georgia (GA) and South Carolina (SC), USA). In the first study (NC), we found no genetic effects on total phenolics, PA and TNC, and there was no relationship between genotype size and foliar biochemistry. In the second study, there were no differences in height growth between sites, but the SC site showed greater diameter (diameter at breast height (DBH)) and volume, most likely due to greater tree mortality (lower stocking) which reduced competition for resources and increased growth of remaining trees. We found a significant site × clone effect for total phenolics with lower productivity clones showing 27-30% higher total phenolic concentrations at the GA site where DBH and volume were lower. In contrast to the predictions of growth-defense theory, clone volume was positively associated with total phenolic concentrations at the higher volume SC site, and PA concentrations at the lower volume GA site. Overall, we found no evidence of a trade-off between genotype size and defense, and genetic potential for improved growth may include increased allocation to some

Long-Term Muscle Fatigue After Standing Work.

PubMed

Garcia, Maria-Gabriela; Läubli, Thomas; Martin, Bernard J

2015-11-01

The aims of this study were to determine long-term fatigue effects in the lower limbs associated with standing work and to estimate possible age and gender influences. The progressive accumulation of muscle fatigue effects is assumed to lead to musculoskeletal disorders, as fatigue generated by sustained low-level exertions exhibits long-lasting effects. However, these effects have received little attention in the lower limbs. Fourteen men and 12 women from two different age groups simulated standing work for 5 hr including 5-min seated rest breaks and a 30-min lunch. The younger group was also tested in a control day. Muscle fatigue was quantified by electrically induced muscle twitches (muscle twitch force [MTF]), postural stability, and subjective evaluation of discomfort. MTF showed a significant fatigue effect after standing work that persisted beyond 30 min after the end of the workday. MTF was not affected on the control day. The center of pressure displacement speed increased significantly over time after standing work but was also affected on the control day. Subjective evaluations of discomfort indicated a significant increase in perception of fatigue immediately after the end of standing work; however, this perception did not persist 30 min after. Age and gender did not influence fatigue. Objective measures show the long-term effects of muscle fatigue after 5 hr of standing work; however, this fatigue is no longer perceived after 30 min of rest postwork. The present results suggest that occupational activities requiring prolonged standing are likely to contribute to lower-extremity and/or back disorders. © 2015, Human Factors and Ergonomics Society.

Effect of Fertilization on Growth and Wood Properties of Thinned and Un-thinned Mid-rotation Loblolly Pine (Pinus taeda L.) Stands

Treesearch

Finto Antony; Laurence R. Schimleck; Richard F. Daniels; Alexander Clark

2011-01-01

Growth and wood properties were measured on breast height cores collected from two stands, New Bern and Bertie, located in the lower Coastal Plain of North Carolina. The New Bern site was thinned before fertilizer application, and the Bertie site was not. The study was laid out in a randomized complete block design with each treatment replicated in four blocks at New...

Visual Basic Growth-and-Yield Models With A Merchandising Optimizer For Planted Slash and Loblolly Pine in the West Gulf Region

Treesearch

R.L. Busby; S.J. Chang; P.R. Pasala; J.C.G. Goelz

2004-01-01

We developed two growth-and-yield models for thinned and unthinned plantations of slash pine (Pinus elliottii Engelm. var elliottii) and loblolly pine (P. taeda L.). The models, VB Merch-Slash and VB Merch-Lob, can be used to forecast product volumes and stand values for stands partitioned into 1-inch diameter-at...

Managing Leaf Area for Maximum Volume Production in a Loblolly Pine Plantation

Treesearch

Shufang Yu; Quang V. Cao; Jim L. Chambers; Zhenmin Tang; James D. Haywood

1999-01-01

To manage loblolly pine (Pinus taeda L.) stands for maximum volume growth, the relationships between volume growth and leaf area at the tree and stand level under different cultural practices (thinning and fertilization) were examined. Forty-eight trees were harvested in 1995, six years after treatment, for individual tree measurements, and 336...

Chapter 8 optimized test design for identification of the variation of elastic stiffness properties of Loblolly Pine (Pinus taeda) pith to bark

Treesearch

David Kretschmann; John Considine; F. Pierron

2016-01-01

This article presents the design optimization of an un-notched Iosipescu test specimen whose goal is the characterization of the material elastic stiffnesses of a Loblolly (Pinus taeda) or Lodgepole pine (Pinus contorta) sample in one single test. A series of finite element (FE) and grid simulations were conducted to determine displacement and strain fields for various...

A Consensus Map for Loblolly Pine (Pinus taeda L.). I. Construction and Integration of Individual Linkage Maps From TwoOutbred Three-Generation Pedigrees

Treesearch

Mitchell M. Sewell; Bradley K. Sherman; David B. Neale

1998-01-01

A consensus map for loblolly pine (Pinus taeda L.) was constructed from the integration of linkage data from two unrelated three-generation out bred pedigrees. The progeny segregation data from restriction fragment length polymorphism, random amplified polymorphic DNA, and isozyme genetic markers from each pedigree were recoded to reflect the two independent...

Breeding bird community response to establishing intercropped switchgrass in intensively-managed pine stands

USGS Publications Warehouse

Loman, Zachary G.; Riffell, Samuel K.; Wheat, Bradley R.; Miller, Darrin A.; Martin, James A.; Vilella, Francisco

2014-01-01

Intercropping switchgrass (Panicum virgatum L.) between tree rows within young pine (Pinus spp.) plantations is a potential method to generate lignocellulosic biofuel feedstocks within intensively managed forests. Intensively managed pine supports a diverse avian assemblage potentially affected by establishment and maintenance of an annual biomass feedstock via changes in plant communities, dead wood resources, and habitat structure. We sought to understand how establishing switchgrass on an operational scale affects bird communities within intercropped plantations as compared to typical intensively managed loblolly pine (Pinus taeda L.) forest. We conducted breeding bird point counts using distance sampling for three years (2011–2013) following establishment of intercropped switchgrass stands (6 replicates), traditionally-managed pine plantations, and switchgrass-only plots (0.1 km2 minimum) in Kemper Co., MS. We detected 59 breeding bird species from 11,195 detections. Neotropical migrants and forest-edge associated species were less abundant in intercropped plots than controls the first two years after establishment and more abundant in year three. Short distance migrants and residents were scarce in intercropped and control plots initially, and did not differ between these two treatments in any year. Species associated with pine-grass habitat structure were less abundant initially in intercropped plots, but converged with pine controls in subsequent years. Switchgrass monocultures provided minimal resources for birds. If songbird conservation is a management priority, managers should consider potential reductions of some breeding birds for one to two years following intercropping. It is unclear how these relationships may change outside the breeding season and as stands age.

Soricid response to coarse woody debris manipulations in Coastal Plain loblolly pine forests.

Treesearch

Kurtis R. Moseley; Audrey K. Owens; Steven B. Castleberry; W. Mark Ford; John C. Kilgo; Timothy S. McCay

2009-01-01

We assessed shrew (soricids) response to coarse woody debris (CWD) manipulations in managed upland loblolly pine (Pinus taeda) stands in the upper Coastal Plain of South Carolina over multiple years and...

Gender-based differences in the cardiovascular response to standing

NASA Technical Reports Server (NTRS)

Gotshall, Robert W.; Tsai, Pai-Feng; Frey, Mary A. B.

1991-01-01

The cardiovascular responses of men and women to the stand test were compared by measuring respective values for heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance during a 5-min supine and a 5-min standing test in ten subjects of each gender. It was found that, while the male and female subjects had similar heart rate values, all other responses exhibited greater changes in men than in women. While differences in the height of the subjects did not account for differences in cardiovascular responses, no mechanism responsible for these differences could be identified.

Estimating maximum mean canopy stomatal conductance for use in models

Treesearch

Brent E. Ewers; Ram Oren; Kurt H. Johnsen; J.J Landsberg

2001-01-01

Fertilized (F) and irrigated and fertilized (IF) stands of Pinus taeda L. produced twice the leaf area index of irrigated (I) and control (C) stands. Based on sap flux-scaled mean stomatal conductance (GS), we found that stomatal conductance in F was half that in other treatments. During the growing season, GS was related to...

Growth and development of loblolly pine in a spacing trial planted in Hawaii

Treesearch

William R. Harms; Craig D. Whitesell; Dean S. DeBell

2000-01-01

Loblolly pine (Pinus taeda L) was planted at four square spacings (1.8, 2.4, 3.0, and 3.7 m) on the Island of Maui in 1961, and measured periodically for 34 years. Patterns of stand growth and development were examined and compared with yield model estimates of stand characteristics of plantations of the...

Soil change and loblolly pine (Pinus taeda) seedling growth following site preparation tillage in the Upper Coastal Plain of the southeastern United States

Treesearch

Chad M. Lincoln; Rodney E. Will; Lawrence A. Morris; Emily A. Carter; Daniel Markewtiz; John R. Britt; Ben Cazell; Vic Ford

2007-01-01

To determine the relationship between changes in soil physical properties due to tillage and growth of loblolly pine (Pinus taeda L.) seedlings, we measured soil moisture and penetration resistance for a range of tillage treatments on two Upper Coastal Plain sites in Georgia and correlated these measurements to the growth of individual seedlings. The...

Repetitive sit-to-stand training with the step-foot position on the non-paretic side, and its effects on the balance and foot pressure of chronic stroke subjects

PubMed Central

Kim, Kyung; Kim, Young Mi; Kang, Dong Yeon

2015-01-01

[Purpose] This study aimed to improve the asymmetrical weight-bearing ratio by applying repetitive sit-to-stand training methods that feature a step-foot position to the paretic-side foot of hemiplegic patients; it sought also to provide the information needed to apply weight-bearing and balance training to hemiplegic patients. [Subjects and Methods] The subjects were divided into two groups: a spontaneous group and a step group. They all performed repetitive sit-to-stand training five times per week for a total of six weeks. The Biodex Balance System, TUG, and 5XSST were used to measure the static and dynamic standing balance of each patient. A foot mat system was used to measure foot pressure. [Results] In the balance measurements, differences in the Overall index, Ant-post index, Med-lat index, Fall risk index, TUG, and 5XSST after training was significantly different between the two study groups. In evaluating foot pressure measurements, we found that the COP (Ant-post), Peak pressure: hind foot, and Contact area: hind foot measurements significantly differed between the groups after the training. [Conclusion] Repetitive sit-to-stand training that involves positioning the non-paretic leg upward can be considered a significant form of training that improves the symmetric posture adjustment and balance of hemiplegic patients following a stroke. PMID:26357448

Short-term impacts of nutrient manipulations on leaf gas exchange and biomass partitioning in contrasting 2-year-old Pinus taeda clones during seedling establishment

Treesearch

Michael C. Tyree; John R. Seiler; Chris A. Maier

2009-01-01

We conducted a 1-year greenhouse experiment to assess the impact of nutrient manipulations on seedling growth, biomass partitioning, and leaf gas exchange between two fast growing Pinus taeda clones that differed in growth efficiency. After 1 year we observed significant treatment and treatment by clone effects on growth, biomass partitioning, and...

Quantifying and mapping spatial variability in simulated forest plots

Treesearch

Gavin R. Corral; Harold E. Burkhart

2016-01-01

We used computer simulations to test the efficacy of multivariate statistical methods to detect, quantify, and map spatial variability of forest stands. Simulated stands were developed of regularly-spaced plantations of loblolly pine (Pinus taeda L.). We assumed no affects of competition or mortality, but random variability was added to individual tree characteristics...

Effects of the silvicultural intensity on the 4-years growth and leaf-level physiology of loblolly pine varieties

Treesearch

Marco Yanez; John Seiler; Thomas Fox

2015-01-01

The role that genetic improvement plays in the increase of productivity in loblolly pine (Pinus taeda L.) in the South has been recognized (McKeand and others 2003). Varietal forestry has the potential to improve the productivity and quality of loblolly pine stands, and higher genetic gains can be achieved in volume and stand uniformity (Zobel and Talbert 1984).

LAI-2000 Accuracy, Precision, and Application to Visual Estimation of Leaf Area Index of Loblolly Pine

Treesearch

Jason A. Gatch; Timothy B. Harrington; James P. Castleberry

2002-01-01

Leaf area index (LAI) is an important parameter of forest stand productivity that has been used to diagnose stand vigor and potential fertilizer response of southern pines. The LAI-2000 was tested for its ability to provide accurate and precise estimates of LAI of loblolly pine (Pinus taeda L.). To test instrument accuracy, regression was used to...

Long-term Root Growth Response to Thinning, Fertilization, and Water Deficit in Plantation Loblolly Pine

Treesearch

M.A. Sword-Sayer; Z. Tang

2004-01-01

High water deficits limit the new root growth of loblolly pine (Pinus taeda L.), potentially reducing soil resource availability and stand growth. We evaluated new root growth and stand production in response to thinning and fertilization in loblolly pine over a 6-year period that consisted of 3 years of low water deficit followed by 3 years of high...

Volume growth of pine and hardwood in uneven-aged loblolly pine-upland hardwood mixtures

Treesearch

Robert M. Farrar; Paul A. Murphy; Daniel J. Leduc

1989-01-01

Results are reported from an exploratory investigation of stand-level periodic volume growth of uneven-aged mixed loblolly pine (Pinus taeda L.)-upland hardwood stands on good sites in southeastern Arkansas. A restricted set of replicated observations was extracted from an extensive CFI database involving varying pine-hardwood mixtures to form an array of plots with...

Use of isoenzyme techniques in forest genetics research

Treesearch

M. Thompson Conkle; W. T. Adams

1977-01-01

Genetic variation among loblolly pine (Pinus taeda L.) samples from a natural stand and among clones in seed orchards was analyzed using simply inherited isozyme markers. Alleles for eleven enzyme loci were found useful for genotyping trees in a natural stand in North Carolina. The pines were highly variable with as many as seven alleles per isozyme...

A comparison of loblolly pine growth and yield on pure pine and mixed pine-hardwood sites

Treesearch

James D. Haywood; John R. Toliver

1989-01-01

The case histories of four loblolly pine (Pinus taeda L.) sites were examined to determine if differences in growth and yield could be associated with stand type. The stand types were pure loblolly pine and mixed loblolly pine-hardwood. All sites were located on silt loam soils and mechanical site preparation was carried out on all sites before...

Specific gravity responses of slash and loblolly pine following mid-rotation fertilization

Treesearch

Kimberly R. Love-Myers; Alexander Clark III; Laurence R. Schimleck; Eric J. Jokela; Richard F. Daniels

2009-01-01

Wood quality attributes were examined in six stands of slash pine (Pinus elliottii Engelm. var. elliottii) and loblolly pine (P. taeda L.) in the lower Coastal Plain of Georgia and Florida. Several plots comprised each stand, and each plot was divided so that it received three fertilizer treatments: a control treatment with herbaceous weed control at planting...

Snag characteristics and dynamics following natural and artificially induced mortality in a managed loblolly pine forest

Treesearch

Stanley Zarnoch; Mark A. Vukovich; John C. Kilgo; John I. Blake

2013-01-01

A 14-year study of snag characteristics was established in 41- to 44-year-old loblolly pine (Pinus taeda L.) stands in southeastern USA. During the initial 5.5 years, no stand manipulation or unusually high-mortality events occurred. Afterwards, three treatments were applied consisting of trees thinned and removed, trees felled and not removed, and artificial creation...

Relationship between morphologic somatotypes and standing posture equilibrium.

PubMed

Allard, P; Nault, M L; Hinse, S; LeBlanc, R; Labelle, H

2001-01-01

Previous studies have identified height and weight as important factors affecting quiet standing stability but studies have not addressed body morphology as a global factor. Using anthropometric measurements, the morphologic somatotypes were defined in terms of body composition and structure. The aim of this study was to test the hypothesis that morphologic somatotypes were related to standing posture equilibrium in able-bodied girls. A total of 43 able-bodied girls having a mean age of 13.8 +/- 2.2 years participated in this study. Somatotype measurements were taken to determine their endomorphic, mesomorphic or ectomorphic components. Then, subjects were asked to stand still on a force platform for 64 s with their eyes opened, feet about 23 cm apart and arms aligned with the trunk. Afterwards, subjects were grouped based on the highest value of their somatotype component. There was no statistical difference in age, height and weight among the groups. The surface area of an ellipse delineated by the displacement of the centre of pressure (COP) was statistically larger (236.9 +/- 134.3 mm2) for the ectomorphs than for the endomorphs 137.7 +/- 71.4 mm2). The minor axis was longer (8.1 +/- 2.9 mm) for the ectomorphs than for the endomorphs (5.7 +/- 2.2 mm). The decrease in standing posture stability of the ectomorphic group was attributed to a relatively low muscle component, a high height weight ratio and an elevated position of the body centre of mass in this population of girls. Somatotypes should be considered when assessing standing posture in both able-bodied subjects and patients.

Heading assessment by "tunnel vision" patients and control subjects standing or walking in a virtual reality environment.

PubMed

Apfelbaum, Henry; Pelah, Adar; Peli, Eli

2007-01-01

Virtual reality locomotion simulators are a promising tool for evaluating the effectiveness of vision aids to mobility for people with low vision. This study examined two factors to gain insight into the verisimilitude requirements of the test environment: the effects of treadmill walking and the suitability of using controls as surrogate patients. Ten "tunnel vision" patients with retinitis pigmentosa (RP) were tasked with identifying which side of a clearly visible obstacle their heading through the virtual environment would lead them, and were scored both on accuracy and on their distance from the obstacle when they responded. They were tested both while walking on a treadmill and while standing, as they viewed a scene representing progress through a shopping mall. Control subjects, each wearing a head-mounted field restriction to simulate the vision of a paired patient, were also tested. At wide angles of approach, controls and patients performed with a comparably high degree of accuracy, and made their choices at comparable distances from the obstacle. At narrow angles of approach, patients' accuracy increased when walking, while controls' accuracy decreased. When walking, both patients and controls delayed their decisions until closer to the obstacle. We conclude that a head-mounted field restriction is not sufficient for simulating tunnel vision, but that the improved performance observed for walking compared to standing suggests that a walking interface (such as a treadmill) may be essential for eliciting natural perceptually-guided behavior in virtual reality locomotion simulators.

Effects of canopy structure and cultural treatments on the survival and growth of Pinus palustris Mill. seedlings underplanted in Pinus taeda L. stands

Treesearch

Benjamin O. Knapp; G. Geoff Wang; Joan L. Walker

2013-01-01

Longleaf pine restoration is a common management objective in the southeastern United States and requires artificial regeneration of longleaf pines on sites currently dominated by loblolly pine. In many cases, retention of canopy trees during stand conversion may be desirable to promote ecological function and meet conservation objectives. We tested the effects of...

The effect of induced heat waves on Pinus taeda and Quercus rubra seedlings in ambient and elevated CO2 atmospheres.

PubMed

Ameye, Maarten; Wertin, Timothy M; Bauweraerts, Ingvar; McGuire, Mary Anne; Teskey, Robert O; Steppe, Kathy

2012-10-01

Here, we investigated the effect of different heat-wave intensities applied at two atmospheric CO2 concentrations ([CO2]) on seedlings of two tree species, loblolly pine (Pinus taeda) and northern red oak (Quercus rubra). Seedlings were assigned to treatment combinations of two levels of [CO2] (380 or 700 μmol mol(-1)) and four levels of air temperature (ambient, ambient +3°C, or 7-d heat waves consisting of a biweekly +6°C heat wave, or a monthly +12°C heat wave). Treatments were maintained throughout the growing season, thus receiving equal heat sums. We measured gas exchange and fluorescence parameters before, during and after a mid-summer heat wave. The +12°C heat wave, significantly reduced net photosynthesis (Anet) in both species and [CO2] treatments but this effect was diminished in elevated [CO2]. The decrease in Anet was accompanied by a decrease in Fv'/Fm' in P. taeda and ΦPSII in Q. rubra. Our findings suggest that, if soil moisture is adequate, trees will experience negative effects in photosynthetic performance only with the occurrence of extreme heat waves. As elevated [CO2] diminished these negative effects, the future climate may not be as detrimental to plant communities as previously assumed. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Fertilization with urea, ammonium and nitrate produce different effects on growth, hydraulic traits and drought tolerance in Pinus taeda seedlings.

PubMed

Faustino, Laura I; Moretti, Ana P; Graciano, Corina

2015-10-01

Urea fertilization decreases Pinus taeda L. growth in clay soils of subtropical areas. The negative effect of urea is related to changes in some hydraulic traits, similar to those observed in plants growing under drought. The aims of this work were (i) to determine whether different sources of nitrogen applied as fertilizers produce similar changes in growth and hydraulic traits to those observed by urea fertilization and (ii) to analyze the impact of those changes in plant drought tolerance. Plants fertilized with urea, nitrate [Formula: see text] or ammonium [Formula: see text] were grown well watered or with reduced water supply. Urea and [Formula: see text] fertilization reduced plant growth and increased root hydraulic conductance scaled by root dry weight (DW). [Formula: see text] fertilization did not reduce plant growth and increased shoot hydraulic conductance and stem hydraulic conductivity. We conclude that [Formula: see text] is the ion involved in the changes linked to the negative effect of urea fertilization on P. taeda growth. [Formula: see text] fertilization does not change drought susceptibility and it produces changes in shoot hydraulic traits, therefore plants avoid the depressive effect of fertilization. Urea and [Formula: see text] fertilizers induce changes in DW and root hydraulic conductance and consequently plants are less affected by drought. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of flooring on standing comfort and fatigue.

PubMed

Cham, R; Redfern, M S

2001-01-01

This study investigated the influence of flooring on subjective discomfort and fatigue during standing and on potentially related objective measures. Participants stood for 4 h on each of 7 flooring conditions while performing computer tasks. During the 3rd and 4th h, floor type had a significant effect on a number of subjective ratings, including lower-leg and lower-back discomfort/fatigue and 2 of 4 objective variables (center of pressure weight shift and lower-extremity skin temperature). In addition, lower-leg volumetric measurements showed tendencies toward greater lower-extremity swelling on uncomfortable floors. The hard floor and 1 floor mat condition consistently had the worst discomfort/fatigue and objective ratings. Significant relationships were noted between the affected subjective ratings and objective variables. In general, floor mats characterized by increased elasticity, decreased energy absorption, and increased stiffness resulted in less discomfort and fatigue. Thus flooring properties do affect low-back and lower-leg discomfort/fatigue, but the result may be detectable only after 3 h of standing. Potential applications of this research include the reduction of work-related health problems associated with long-term standing.

Patterns of Population Structure and Environmental Associations to Aridity Across the Range of Loblolly Pine (Pinus taeda L., Pinaceae)

PubMed Central

Eckert, Andrew J.; van Heerwaarden, Joost; Wegrzyn, Jill L.; Nelson, C. Dana; Ross-Ibarra, Jeffrey; González-Martínez, Santíago C.; Neale, David. B.

2010-01-01

Natural populations of forest trees exhibit striking phenotypic adaptations to diverse environmental gradients, thereby making them appealing subjects for the study of genes underlying ecologically relevant phenotypes. Here, we use a genome-wide data set of single nucleotide polymorphisms genotyped across 3059 functional genes to study patterns of population structure and identify loci associated with aridity across the natural range of loblolly pine (Pinus taeda L.). Overall patterns of population structure, as inferred using principal components and Bayesian cluster analyses, were consistent with three genetic clusters likely resulting from expansions out of Pleistocene refugia located in Mexico and Florida. A novel application of association analysis, which removes the confounding effects of shared ancestry on correlations between genetic and environmental variation, identified five loci correlated with aridity. These loci were primarily involved with abiotic stress response to temperature and drought. A unique set of 24 loci was identified as FST outliers on the basis of the genetic clusters identified previously and after accounting for expansions out of Pleistocene refugia. These loci were involved with a diversity of physiological processes. Identification of nonoverlapping sets of loci highlights the fundamental differences implicit in the use of either method and suggests a pluralistic, yet complementary, approach to the identification of genes underlying ecologically relevant phenotypes. PMID:20439779

Patterns of population structure and environmental associations to aridity across the range of loblolly pine (Pinus taeda L., Pinaceae).

PubMed

Eckert, Andrew J; van Heerwaarden, Joost; Wegrzyn, Jill L; Nelson, C Dana; Ross-Ibarra, Jeffrey; González-Martínez, Santíago C; Neale, David B

2010-07-01

Natural populations of forest trees exhibit striking phenotypic adaptations to diverse environmental gradients, thereby making them appealing subjects for the study of genes underlying ecologically relevant phenotypes. Here, we use a genome-wide data set of single nucleotide polymorphisms genotyped across 3059 functional genes to study patterns of population structure and identify loci associated with aridity across the natural range of loblolly pine (Pinus taeda L.). Overall patterns of population structure, as inferred using principal components and Bayesian cluster analyses, were consistent with three genetic clusters likely resulting from expansions out of Pleistocene refugia located in Mexico and Florida. A novel application of association analysis, which removes the confounding effects of shared ancestry on correlations between genetic and environmental variation, identified five loci correlated with aridity. These loci were primarily involved with abiotic stress response to temperature and drought. A unique set of 24 loci was identified as F(ST) outliers on the basis of the genetic clusters identified previously and after accounting for expansions out of Pleistocene refugia. These loci were involved with a diversity of physiological processes. Identification of nonoverlapping sets of loci highlights the fundamental differences implicit in the use of either method and suggests a pluralistic, yet complementary, approach to the identification of genes underlying ecologically relevant phenotypes.

Inflight exercise affects stand test responses after space flight

NASA Technical Reports Server (NTRS)

Lee, S. M.; Moore, A. D. Jr; Fritsch-Yelle, J. M.; Greenisen, M. C.; Schneider, S. M.

1999-01-01

PURPOSE: The purpose of this study was to determine whether exercise performed by Space Shuttle crew members during short-duration space flights (9-16 d) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 h of landing. METHODS: Thirty crew members performed self-selected inflight exercise and maintained exercise logs to monitor their exercise intensity and duration. Two subjects participated in this investigation during two different flights. A 10-min stand test, preceded by at least 6 min of quiet supine rest, was completed 10-15 d before launch (PRE) and within 4 h of landing (POST). Based upon their inflight exercise records, subjects were grouped as either high (HIex: > or = 3 times/week, HR > or = 70% HRmax, > or = 20 min/session, N = 11), medium (MEDex: > or = 3 times/week, HR < 70% HRmax, > or = 20 min/session, N = 10), or low (LOex: < or = 3 times/week, HR and duration variable, N = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, P < or = 0.05). RESULTS: There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared with PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36 +/- 5 bpm) compared with HIex or MEDex groups (25 +/- 1 bpm; 22 +/- 2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after space flight in the MEDex and HIex groups but was significantly greater in the LOex group (PRE: -9 +/- 3; POST: -19 +/- 4 mm Hg). CONCLUSIONS: Thus, moderate to high levels of inflight exercise attenuated HR and PP responses to standing after space flight.

Regeneration of southern pine stands under ecosystem management in the Piedmont

Treesearch

James W. McMinn; Alexander Clark

1999-01-01

Ecosystem-oriented management is being used on southern National Forests to conserve biodiversity, improve the balance among forest values, and achieve sustainable conditions. This paper reports on the regeneration phase of a study to identify the implications of ecosystem management practices on loblolly pine (Pinus taeda L.) and shortleaf (I? echinata Mill) pine...

Assessment of Muscle Fatigue Associated with Prolonged Standing in the Workplace

PubMed Central

Omar, Abdul Rahman; Saman, Alias Mohd; Othman, Ibrahim

2012-01-01

Objectives The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods. Methods The psychological fatigue experienced by the workers was obtained through questionnaire surveys. Meanwhile, muscle activity has been analyzed using surface electromyography (sEMG) measurement. Lower extremities muscles include: erector spinae, tibialis anterior, and gastrocnemius were concurrently measured for more than five hours of standing. Twenty male production workers in a metal stamping company participated as subjects in this study. The subjects were required to undergo questionnaire surveys and sEMG measurement. Results Results of the questionnaire surveys found that all subjects experienced psychological fatigue due to prolonged standing jobs. Similarly, muscle fatigue has been identified through sEMG measurement. Based on the non-parametric statistical test using the Spearman's rank order correlation, the left erector spinae obtained a moderate positive correlation and statistically significant (rs = 0.552, p < 0.05) between the results of questionnaire surveys and sEMG measurement. Conclusion Based on this study, the authors concluded that prolonged standing was contributed to psychological fatigue and to muscle fatigue among the production workers. PMID:22953228

Energy and water balance of two contrasting loblolly pine plantations on the lower coastal plain of North Carolina, USA

Treesearch

G. Sun; A. Noormets; M.J. Gavazzi; S.G. McNulty; J. Chen; J.-C. King Domec; D.M. Amatya; R.W. Skaggs

2010-01-01

During 2005–2007, we used the eddy covariance and associated hydrometric methods to construct energy and water budgets along a chronosequence of loblolly pine (Pinus taeda) plantations that included a mid-rotation stand (LP) (i.e., 13–15 years old) and a recently established stand on a clearcut site (CC) (i.e., 4–6 years old) in Eastern...

Performance of a Tracked Feller-Buncher with a Shear Head Operating in Small-Diameter Pine

Treesearch

J. Klepac

2013-01-01

A Tigercat 845D tracked feller-buncher equipped with a shear head was evaluated while performing a clearcut in a 15-year old Loblolly pine (Pinus taeda) plantation and a 18-year old natural stand. Mean density of the plantation was 573 TPA (Trees per Acre) while the natural stand averaged 328 TPA, with a slightly higher density of 390 TPA in the study area. Total cycle...

49 CFR 655.5 - Stand-down waivers for drug testing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Stand-down waivers for drug testing. 655.5 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PREVENTION OF ALCOHOL MISUSE AND PROHIBITED DRUG USE IN TRANSIT OPERATIONS General § 655.5 Stand-down waivers for drug testing. (a) An employer subject to this part may...

49 CFR 655.5 - Stand-down waivers for drug testing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Stand-down waivers for drug testing. 655.5 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PREVENTION OF ALCOHOL MISUSE AND PROHIBITED DRUG USE IN TRANSIT OPERATIONS General § 655.5 Stand-down waivers for drug testing. (a) An employer subject to this part may...

49 CFR 655.5 - Stand-down waivers for drug testing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Stand-down waivers for drug testing. 655.5 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PREVENTION OF ALCOHOL MISUSE AND PROHIBITED DRUG USE IN TRANSIT OPERATIONS General § 655.5 Stand-down waivers for drug testing. (a) An employer subject to this part may...

49 CFR 655.5 - Stand-down waivers for drug testing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Stand-down waivers for drug testing. 655.5 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PREVENTION OF ALCOHOL MISUSE AND PROHIBITED DRUG USE IN TRANSIT OPERATIONS General § 655.5 Stand-down waivers for drug testing. (a) An employer subject to this part may...

49 CFR 655.5 - Stand-down waivers for drug testing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Stand-down waivers for drug testing. 655.5 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PREVENTION OF ALCOHOL MISUSE AND PROHIBITED DRUG USE IN TRANSIT OPERATIONS General § 655.5 Stand-down waivers for drug testing. (a) An employer subject to this part may...

Interactions of Hylastes Species (Coleoptera: Scolytidae) with Leptographium Species Associated with Loblolly Pine Decline

Treesearch

Lori G. Eckhardt; Richard A. Goyer; Kier Klepzig; John P. Jones

2004-01-01

Abstract Hylastes spp. (Coleoptera: Scolytidae)were evaluated as potential vectors of Leptographium spp. fungi. Bark beetles were trapped from stands of loblolly pine, Pinus taeda L., exhibiting a range of decline symptoms in central Alabama. Under controlled conditions, field-collected adult...

Standing stability enhancement with an intelligent powered transfemoral prosthesis.

PubMed

Lawson, Brian Edward; Varol, Huseyin Atakan; Goldfarb, Michael

2011-09-01

The authors have developed a ground-adaptive standing controller for a powered knee and ankle prosthesis which is intended to enhance the standing stability of transfemoral amputees. The finite-state-based controller includes a ground-searching phase, a slope estimation phase, and a joint impedance modulation phase, which together enable the prosthesis to quickly conform to the ground and provide stabilizing assistance to the user. In order to assess the efficacy of the ground-adaptive standing controller, the control approach was implemented on a powered knee and ankle prosthesis, and experimental data were collected on an amputee subject for a variety of standing conditions. Results indicate that the controller can estimate the ground slope within ±1° over a range of ±15°, and that it can provide appropriate joint impedances for standing on slopes within this range.

Heading assessment by “tunnel vision” patients and control subjects standing or walking in a virtual reality environment

PubMed Central

APFELBAUM, HENRY; PELAH, ADAR; PELI, ELI

2007-01-01

Virtual reality locomotion simulators are a promising tool for evaluating the effectiveness of vision aids to mobility for people with low vision. This study examined two factors to gain insight into the verisimilitude requirements of the test environment: the effects of treadmill walking and the suitability of using controls as surrogate patients. Ten “tunnel vision” patients with retinitis pigmentosa (RP) were tasked with identifying which side of a clearly visible obstacle their heading through the virtual environment would lead them, and were scored both on accuracy and on their distance from the obstacle when they responded. They were tested both while walking on a treadmill and while standing, as they viewed a scene representing progress through a shopping mall. Control subjects, each wearing a head-mounted field restriction to simulate the vision of a paired patient, were also tested. At wide angles of approach, controls and patients performed with a comparably high degree of accuracy, and made their choices at comparable distances from the obstacle. At narrow angles of approach, patients’ accuracy increased when walking, while controls’ accuracy decreased. When walking, both patients and controls delayed their decisions until closer to the obstacle. We conclude that a head-mounted field restriction is not sufficient for simulating tunnel vision, but that the improved performance observed for walking compared to standing suggests that a walking interface (such as a treadmill) may be essential for eliciting natural perceptually-guided behavior in virtual reality locomotion simulators. PMID:18167511

Stand density index in uneven-aged ponderosa pine stands

Treesearch

C.W. Woodall; C.E. Fiedler; K.S. Milner

2003-01-01

Stand density index (SDI) was developed to quantify relative stand density in even-aged stands. Application of SDI in uneven-aged stands has been described mathematically but not justified biologically. Diameter-class trends in SDI and sapwood area across 14 uneven-aged ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) stands in eastern...

AN EVALUATION OF TWO GROUND-BASED CROWN CLOSURE ESTIMATION TECHNIQUES COMPARED TO CROWN CLOSURE ESTIMATES DERIVED FROM HIGH RESOLUTION IMAGERY

EPA Science Inventory

Two ground-based canopy closure estimation techniques, the Spherical Densitometer (SD) and the Vertical Tube (VT), were compared for the effect of deciduous understory on dominant/co-dominant crown closure estimates in even-aged loblolly (Pinus taeda) pine stands located in the N...

AN EVALUATION OF TWO GROUND-BASED CROWN CLOSURE ESTIMATION TECHNIQUES COMPARED TO CROWN CLOSURE ESTIMATES DERIVED FROM HIGH RESOLUTION IMAGERY

EPA Science Inventory

Two ground-based canopy closure estimation techniques, the Spherical Densitometer (SD) and the Vertical Tube (VT), were compared for the effect of deciduous understory on dominantlco-dominant crown closure estimates in even-aged loblolly (Pinus taeda) pine stands located in the N...

A Standing-Wave Experiment with a Guitar

NASA Astrophysics Data System (ADS)

Inman, Fred W.

2006-10-01

When teaching standing waves, one often uses as examples musical instruments with strings, e.g., pianos, violins, and guitars. In today's popular music culture, young people may be more familiar with guitars than any other string instrument. I was helping my 15-year-old granddaughter make some repairs and adjustments to her electric guitar, and the subject of the spacing between the frets on the fingerboard was raised. I told her that the physics of standing waves and the equal tempered musical scale dictate the location of the frets. The purpose of this paper is to suggest that students might be introduced to the physics of standing waves using a guitar and to the formula for the fret locations. By measuring the positions of the frets, this formula can be tested.

Comparison of Biodynamic Responses in Standing and Seated Human Bodies

NASA Astrophysics Data System (ADS)

MATSUMOTO, Y.; GRIFFIN, M. J.

2000-12-01

The dynamic responses of the human body in a standing position and in a sitting position have been compared. The apparent mass and transmissibilities to the head, six locations along the spine, and the pelvis were measured with eight male subjects exposed to vertical whole-body vibration. In both postures, the principal resonance in the apparent mass occurred in the range 5-6 Hz, with slightly higher frequencies and lower apparent mass in the standing posture. There was greater transmission of vertical vibration to the pelvis and the lower spine and greater relative motion within the lower spine in the standing posture than in the sitting posture at the principal resonance and at higher frequencies. Transmissibilities from the supporting surface (floor or seat) to the thoracic region had similar magnitudes for both standing and sitting subjects. The lumbar spine has less lordosis and may be more compressed and less flexible in the sitting posture than in the standing posture. This may have reduced the relative motions between lumbar vertebrae and both the supporting vibrating surface and the other vertebrae in the sitting posture. The characteristics of the vibration transmitted to the pelvis may have differed in the two postures due to different transmission paths. Increased forward rotation of the pelvis in the standing posture may have caused the differences in responses of the pelvis and the lower spine that were observed between the two postures.

New Marshall Center Test Stand 4697 Construction Time-Lapse

NASA Image and Video Library

2016-09-27

In less than two minutes watch structural Test Stand 4697 rise at NASA's Marshall Space Flight Center from the start of construction in May 2014 to the end of the stand's construction phase in September 2016. The stand will subject the 196,000-gallon liquid oxygen tank of the Space Launch System's massive core stage to the same stresses and pressures it must endure at launch and in flight. Now, Marshall teams are installing sophisticated fluid transfer and pressurization systems, hydraulic controls, electrical control and data systems, fiber optics cables and special test equipment to prepare for the arrival of the test tank in 2017. (NASA/MSFC/David Olive)

Mid-rotation silviculture timing influences nitrogen mineralization of loblolly pine plantations in the mid-south USA

Treesearch

Michael A. Blazier; D. Andrew Scott; Ryan Coleman

2015-01-01

Intensively managed loblolly pine (Pinus taeda L.) plantations often develop nutrient deficiencies near mid-rotation. Common silvicultural treatments for improving stand nutrition at this stage include thinning, fertilization, and vegetation control. It is important to better understand the influence of timing fertilization and vegetation control...

The impact of sit-stand office workstations on worker discomfort and productivity: a review.

PubMed

Karakolis, Thomas; Callaghan, Jack P

2014-05-01

This review examines the effectiveness of sit-stand workstations at reducing worker discomfort without causing a decrease in productivity. Four databases were searched for studies on sit-stand workstations, and five selection criteria were used to identify appropriate articles. Fourteen articles were identified that met at least three of the five selection criteria. Seven of the identified studies reported either local, whole body or both local and whole body subjective discomfort scores. Six of these studies indicated implementing sit-stand workstations in an office environment led to lower levels of reported subjective discomfort (three of which were statistically significant). Therefore, this review concluded that sit-stand workstations are likely effective in reducing perceived discomfort. Eight of the identified studies reported a productivity outcome. Three of these studies reported an increase in productivity during sit-stand work, four reported no affect on productivity, and one reported mixed productivity results. Therefore, this review concluded that sit-stand workstations do not cause a decrease in productivity. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Mortality in second-growth stands of the western white pine type

Treesearch

Richard F. Watt

1954-01-01

Foresters generally accept without alarm the normally small but continuing losses caused by the indigenous agents of mortality in forest stands. When a stand suffers a sudden increase in the rate of mortality, however, attention is focused upon the subject and a host of questions and speculative answers arise. How much growth is nullified by mortality during a rotation...

Multi-site modulation of flux during monolignol formation in loblolly pine (Pinus taeda)

NASA Technical Reports Server (NTRS)

Anterola, A. M.; van Rensburg, H.; van Heerden, P. S.; Davin, L. B.; Lewis, N. G.

1999-01-01

Loblolly pine (Pinus taeda L.) cell suspension cultures secrete monolignols when placed in 8% sucrose/20 mM KI solution, and these were used to identify phenylpropanoid pathway flux-modulating steps. When cells were provided with increasing amounts of either phenylalanine (Phe) or cinnamic acid, cellular concentrations of immediate downstream products (cinnamic and p-coumaric acids, respectively) increased, whereas caffeic and ferulic acid pool sizes were essentially unaffected. Increasing Phe concentrations resulted in increased amounts of p-coumaryl alcohol relative to coniferyl alcohol. However, exogenously supplied cinnamic, p-coumaric, caffeic, and ferulic acids resulted only in increases in their intercellular concentrations, but not that of downstream cinnamyl aldehydes and monolignols. Supplying p-coumaryl and coniferyl aldehydes up to 40, 000-320,000-fold above the detection limits resulted in rapid, quantitative conversion into the monolignols. Only at nonphysiological concentrations was transient accumulation of intracellular aldehydes observed. These results indicate that cinnamic and p-coumaric acid hydroxylations assume important regulatory positions in phenylpropanoid metabolism, whereas cinnamyl aldehyde reduction does not serve as a control point. Copyright 1999 Academic Press.

Structural Characterization of Lignin during Pinus taeda Wood Treatment with Ceriporiopsis subvermispora

PubMed Central

Guerra, Anderson; Mendonça, Régis; Ferraz, André; Lu, Fachuang; Ralph, John

2004-01-01

Pinus taeda wood chips were biotreated with Ceriporiopsis subvermispora under solid-state fermentation for periods varying from 15 to 90 days. Milled wood lignins extracted from sound and biotreated wood samples were characterized by wet-chemical and spectroscopic techniques. Treatment of the lignins by derivatization followed by reductive cleavage (DFRC) made it possible to detect DFRC monomers and dimers that are diagnostic of the occurrence of arylglycerol-β-O-aryl and β-β, β-5, β-1, and 4-O-5 units in the lignin structure. Quantification of these DFRC products indicated that β-O-aryl cleavage was a significant route for lignin biodegradation but that β-β, β-5, β-1, and 4-O-5 linkages were more resistant to the biological attack. The amount of aromatic hydroxyls did not increase with the split of β-O-4 linkages, suggesting that the β-O-4 cleavage products remain as quinone-type structures as detected by UV and visible spectroscopy. Nuclear magnetic resonance techniques also indicated the formation of new substructures containing nonoxygenated, saturated aliphatic carbons (CH2 and CH3) in the side chains of lignins extracted from biotreated wood samples. PMID:15240285

Multi-muscle electrical stimulation and stand training: Effects on standing.

PubMed

Momeni, Kamyar; Ramanujam, Arvind; Garbarini, Erica L; Forrest, Gail F

2018-02-15

To examine the biomechanical and neuromuscular effects of a longitudinal multi-muscle electrical stimulation (submaximal intensities) training of the lower limbs combined with/without activity-based stand training, on the recovery of stability and function for one individual with spinal cord injury (SCI). Single-subject, longitudinal study. Neuroplasticity laboratory. A 34-year-old male, with sensory- and motor-complete SCI (C5/C6). Two consecutive interventions: 61 hours of supine, lower-limb ES (ES-alone) and 51 hours of ES combined with stand training using an overhead body-weight support system (ST + ES). Clinical measures, trunk stability, and muscle activity were assessed and compared across time points. Trunk Stability Limit (TSL) determined improvements in trunk independence. Functional clinical values increased after both interventions, with further increases post ST + ES. Post ES-alone, trunk stability was maintained at 81% body-weight (BW) loading before failure; post ST + ES, BW loading increased to 95%. TSL values decreased post ST + ES (TSL A/P =54.0 kg.cm, TSL M/L =14.5 kg.cm), compared to ES-alone (TSL A/P =8.5 kg.cm, TSL M/L =3.9 kg.cm). Trunk muscle activity decreased post ST + ES training, compared to ES-alone. Neuromuscular and postural trunk control dramatically improved following the multi-muscle ES of the lower limbs with stand training. Multi-muscle ES training paradigm of the lower limb, using traditional parameters, may contribute to the functional recovery of the trunk.

Variations in rest vertical dimension: effects of standing posture in edentulous patients.

PubMed

Makzoume, Joseph E

2007-01-01

The orientation of a patient's head changes, depending on whether he or she is sitting or standing in a relaxed upright position. An edentulous patient's vertical dimension at rest may show variations that can result in an inaccurate determination of his or her occlusal vertical dimension. This study recorded the rest vertical dimension (RVD) established among 60 totally edentulous subjects who were standing in the position of greatest comfort (self-balance position) and compared it with the patients' RVD when they were seated in a relaxed upright position, with the Frankfort Plane parallel to the horizontal. The RVD was measured (in mm) between two dots located on the midline of the face. Two measurements were made: one when the patient was seated upright and relaxed (with the Frankfort Plane parallel to the horizontal) with no head support, and the other when the patient was standing relaxed on both feet in a self-balance position. Five alternated measurements were made for each subject in each position. A mean RVD was calculated for each subject in each body posture and the mean values from both positions were compared. Statistical analysis was performed using Student's t-test (alpha = 0.05). No significant differences were noted between the RVD of the seated and standing positions (P = 0.67).

Predicting Soil CO2 Efflux Rates in the Loblolly Pine Ecosystem Across the Region

Treesearch

Christopher Gough; John Seiler; Eric Wiseman

2004-01-01

Patterns in soil CO2 efflux (Ec) over a short rotation were examined using a chronosequence approach on South Carolina Coastal Plain and Virginia Piedmont loblolly pine (Pinus taeda L.) stands. Ec was measured over an entire year in four separate age classes at both measurement...

Can Hardwoods Be Eradicated From Pine Sites?

Treesearch

Michael D. Cain; D.A. Yaussy

1984-01-01

Intensive mechanical and chemical treatments were used annually for 12 years to eradicate hardwoods from a selectively managed loblolly (pinus taeda L.) shortleaf (P. echinata Mill.) pine stand in south Arkansas.Although temporarily effective, a succession of indigenous shrubs and trees followed the cessation of eradication...

Silvicultural treatments for converting loblolly pine to longleaf pine dominance: Effects on planted longleaf pine seedlings

Treesearch

Huifeng Hu; G.Geoff Wang; Joan L. Walker; Benjamin O. Knapp

2012-01-01

A field study was installed to test silvicultural treatments for establishing longleaf pine (Pinus palustris Mill) in loblolly pine (P. taeda L.) stands. Harvesting was used to create seven canopy treatments, four with uniformly distributed canopies at different residual basal areas [Control (16.2 m2/ha),...

Competition Impacts on Growth of Naturally Regenerated Loblolly Pine Seedlings

Treesearch

Michael D. Cain

1988-01-01

Intrusive competition control was used for 3 years in a nuturally regenerated, even-aged stand of loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.) in southern Arkansas. Treatments included: no competition control, woody competition control, herbaceous competition control, and total control of nonpine vegetation...

Take a Stand for Standing

ERIC Educational Resources Information Center

Labandz, Stephenie

2010-01-01

As a school-based physical therapist, the author sees children with a wide variety of diagnoses affecting their mobility and motor function. Supported standing is an important part of the routines of those who are unable to stand independently due to issues affecting the neuromuscular system. Being eye-to-eye with their peers and interacting with…

Soccer players have a better standing balance in nondominant one-legged stance

PubMed Central

Barone, Rosario; Macaluso, Filippo; Traina, Marcello; Leonardi, Vincenza; Farina, Felicia; Di Felice, Valentina

2011-01-01

The purpose of this study was to analyze the differences in standing balance during dominant and nondominant one-legged stance among athletes of different sports and sedentary subjects. The right-footed subjects of four groups (sedentary, n = 20; soccer, n = 20; basketball, n = 20; windsurfer n = 20) underwent 5-sec unipedal (left and right foot) stabilometric analysis with open eyes and closed eyes to measure center of pressure (COP) sway path and COP velocity (mean value, anteroposterior, and laterolateral in millimeters per second). The soccer group showed better standing balance on the left leg than the sedentary group (P < 0.05). No other significant differences were observed within and amongst groups. The soccer players have a better standing balance on the nondominant leg because of soccer activity. PMID:24198563

Impact of cognitive task on the posture of elderly subjects with Alzheimer's disease compared to healthy elderly subjects.

PubMed

Manckoundia, Patrick; Pfitzenmeyer, Pierre; d'Athis, Philippe; Dubost, Véronique; Mourey, France

2006-02-01

The aims of this study were to analyze the effects of cognitive task on static posture in Alzheimer's disease (AD) and in healthy elderly (HE) subjects and to evaluate whether those effects were greater in AD subjects than in HE subjects. We performed a posturographic analysis on 13 subjects with mild AD (mean age, 79.7+/-5.1 years, Mini-Mental State Examination scores between 18 and 23) and on 17 HE subjects (mean age, 78.5+/-4.4 years). After watching a video sequence, the subjects were asked to maintain a stable upright posture while standing on a force platform. Then, the postural sway was measured during the following two conditions: (1) quiet standing and (2) both standing and answering questions about the video sequence. We were interested in the center of pressure (CoP) area and path. For each group, the single task was compared to the dual task for the CoP area and path. We also compared the variability of both CoP area (variation of the CoP area between the single and the dual task) and path (variation of the CoP path between the single and the dual task) between the two groups. We showed that there was no significant difference between the single and the dual task in HE subjects concerning the CoP area and path, in contrast to the AD group, and that variability of both the CoP area and path were significantly greater in the AD subjects than in the HE subjects. This finding may contribute to the risk of falls in AD patients. Copyright (c) 2005 Movement Disorder Society.

Sagittal Thoracic and Lumbar Spine Profiles in Upright Standing and Lying Prone Positions Among Healthy Subjects: Influence of Various Biometric Features.

PubMed

Salem, Walid; Coomans, Ysaline; Brismée, Jean-Michel; Klein, Paul; Sobczak, Stéphane; Dugailly, Pierre-Michel

2015-08-01

A prospective study was performed on the assessment of both thoracic and lumbar spine sagittal profiles (from C7 to S1). To propose a new noninvasive method for measuring the spine curvatures in standing and lying prone positions and to analyze their relationship with various biometric characteristics. Modifications of spine curvatures (i.e. lordosis or kyphosis) are of importance in the development of spinal disorders. Studies have emphasized the development of new devices to measure the spine sagittal profiles using a noninvasive and low-cost method. To date, it has not been applied for analyzing both lumbar and thoracic alterations for various positioning. Seventy-five healthy subjects (mean 22.6 ± 4.3 yr) were recruited to participate in this study. Thoracic and lumbar sagittal profiles were assessed in standing and lying prone positions using a 3D digitizer. In addition, several biometric data were collected including maximal trunk isometric strength for flexion and extension movement. Statistical analysis consisted in data comparisons of spine profiles and a multivariate analysis including biometric features, to classify individuals considering low within- and high between-variability. Kyphosis and lordosis angles decreased significantly from standing to lying prone position by an average of 13.4° and 16.6°, respectively. Multivariate analysis showed a sample clustering of 3 homogenous subgroups. The first group displayed larger lordosis and flexibility, and had low data values for height, weight, and strength. The second group had lower values than the overall trend of the whole sample, whereas the third group had larger score values for the torques, height, weight, waist, body mass index, and kyphosis angle but a reduced flexibility. The present results demonstrate a significant effect of the positioning on both thoracic and lumbar spine sagittal profiles and highlight the use of cluster analysis to categorize subgroups after biometric characteristics

What triggers the continuous muscle activity during upright standing?

PubMed

Masani, Kei; Sayenko, Dimitry G; Vette, Albert H

2013-01-01

The ankle extensors play a dominant role in controlling the equilibrium during bipedal quiet standing. Their primary role is to resist the gravity toppling torque that pulls the body forward. The purpose of this study was to investigate whether the continuous muscle activity of the anti-gravity muscles during standing is triggered by the joint torque requirement for opposing the gravity toppling torque, rather than by the vertical load on the lower limbs. Healthy adults subjects stood on a force plate. The ankle torque, ankle angle, and electromyograms from the right lower leg muscles were measured. A ground-fixed support device was used to support the subject at his/her knees, without changing the posture from the free standing one. During the supported condition, which eliminates the ankle torque requirement while maintaining both the vertical load on the lower limbs and the natural upright standing posture, the plantarflexor activity was attenuated to the resting level. Also, this attenuated plantarflexor activity was found only in one side when the ipsilateral leg was supported. Our results suggest that the vertical load on the lower limb is not determinant for inducing the continuous muscle activity in the anti-gravity muscles, but that it depends on the required joint torque to oppose the gravity toppling torque. Copyright © 2012 Elsevier B.V. All rights reserved.

Prior exercise and standing as strategies to circumvent sitting-induced leg endothelial dysfunction.

PubMed

Morishima, Takuma; Restaino, Robert M; Walsh, Lauren K; Kanaley, Jill A; Padilla, Jaume

2017-06-01

We have previously shown that local heating or leg fidgeting can prevent prolonged sitting-induced leg endothelial dysfunction. However, whether physical activity prevents subsequent sitting-induced leg endothelial dysfunction remains unknown. Herein, we tested the hypothesis that sitting-induced leg endothelial dysfunction would be prevented by prior exercise. We also examined if, in the absence of exercise, standing is an effective alternative strategy to sitting for conserving leg endothelial function. Fifteen young healthy subjects completed three randomized experimental trials: (1) sitting without prior exercise; (2) sitting with prior exercise; and (3) standing without prior exercise. Following baseline popliteal artery flow-mediated dilation (FMD) measurements, subjects maintained a supine position for 45 min in the sitting and standing trials, without prior exercise, or performed 45 min of leg cycling before sitting (i.e. sitting with prior exercise trial). Thereafter, subjects were positioned into a seated or standing position, according to the trial, for 3 h. Popliteal artery FMD measures were then repeated. Three hours of sitting without prior exercise caused a significant impairment in popliteal artery FMD (baseline: 3.8±0.5%, post-sitting: 1.5±0.5%, P <0.05), which was prevented when sitting was preceded by a bout of cycling exercise (baseline: 3.8±0.5%, post-sitting: 3.6±0.7%, P >0.05). Three hours of standing did not significantly alter popliteal artery FMD (baseline: 4.1±0.4%, post-standing: 4.3±0.4%, P >0.05). In conclusion, prolonged sitting-induced leg endothelial dysfunction can be prevented by prior aerobic exercise. In addition, in the absence of exercise, standing represents an effective substitute to sitting for preserving leg conduit artery endothelial function. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Looking northeast from Test Stand 'A' superstructure towards Test Stand ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking northeast from Test Stand 'A' superstructure towards Test Stand 'D' tower (4223/E-24, left background), Test Stand 'C' tower (4217/E-18, center), and Test Stand 'B' (4215/E-16, right foreground). - Jet Propulsion Laboratory Edwards Facility, Edwards Air Force Base, Boron, Kern County, CA

Root and stem partitioning of Pinus taeda

Treesearch

Timothy J. Albaugh; H. Lee Allen; Lance W. Kress

2006-01-01

We measured root and stem mass at three sites (Piedmont (P), Coastal Plain (C), and Sandhills (S)) in the southeastern United States. Stand density, soil texture and drainage, genetic makeup and environmental conditions varied with site while differences in tree size at each site were induced with fertilizer additions. Across sites, root mass was about one half of stem...

Potential residual biomass in mature pine stands of the Midsouth, U.S.A.

Treesearch

J.F. Rosson

1989-01-01

The extent, location, and ownership of residual woody biomass available on mature pine timberland prior to the harvest of log-size pine was determined for the Midsouth States. Most of this residual is on non-industrial private timberland. Sweetgum (Liquidambar styraciflua L.) and loblolly pine (Pinus taeda L.) are the dominant species in the residual. Stems of all...

Performance of mixed pine-hardwood stands 16 years after fell-and-burn treatments

Treesearch

Elizabeth M. Blizzard; David H. van Lear; G. Geoff Wang; Thomas A. Waldrop

2006-01-01

Four variations of the fell-and-burn technique were compared for height and volume production on dry Piedmont sites. A two-factorial randomized complete block design of winter versus spring felling, with and without a summer burn, was implemented, followed by planting of loblolly pine (Pinus taeda L.) at 15 x 15 foot spacing. After 16 growing seasons...

Comparative shoulder kinematics during free standing, standing depression lifts and daily functional activities in persons with paraplegia: considerations for shoulder health.

PubMed

Riek, L M; Ludewig, P M; Nawoczenski, D A

2008-05-01

Case series; nonparametric repeated-measures analysis of variance. To compare and contrast three-dimensional shoulder kinematics during frequently utilized upper extremity weight-bearing activities (standing depression lifts used in brace walking, weight-relief raises, transfers) and postures (sitting rest, standing in a frame) in spinal cord injury (SCI). Movement Analysis Laboratory, Department of Physical Therapy, Ithaca College, Rochester, NY, USA. Three female and two male subjects (39.2+/-6.1 years old) at least 12 months post-SCI (14.6+/-6.7 years old), SCI distal to T2 and with an ASIA score of A. The Flock of Birds magnetic tracking device was used to measure three-dimensional positions of the scapula, humerus and thorax during various activities. Standing in a frame resulted in significantly less scapular anterior tilt (AT) and greater glenohumeral external rotation (GHER) than standing depression lifts and weight-relief raises. Standing frame posture offers the most favorable shoulder joint positions (less scapular AT and greater GHER) when compared to sitting rest posture, weight-relief raises, transfers and standing depression lifts. Knowledge of kinematic patterns associated with each activity is an essential first step to understanding the potential impact on shoulder health. Choosing specific activities or modifying techniques within functional activities that promote favorable shoulder positions may preserve long-term shoulder health.

Postural control during quiet bipedal standing in rats

PubMed Central

Sato, Yota; Fujiki, Soichiro; Sato, Yamato; Aoi, Shinya; Tsuchiya, Kazuo; Yanagihara, Dai

2017-01-01

The control of bipedal posture in humans is subject to non-ideal conditions such as delayed sensation and heartbeat noise. However, the controller achieves a high level of functionality by utilizing body dynamics dexterously. In order to elucidate the neural mechanism responsible for postural control, the present study made use of an experimental setup involving rats because they have more accessible neural structures. The experimental design requires rats to stand bipedally in order to obtain a water reward placed in a water supplier above them. Their motions can be measured in detail using a motion capture system and a force plate. Rats have the ability to stand bipedally for long durations (over 200 s), allowing for the construction of an experimental environment in which the steady standing motion of rats could be measured. The characteristics of the measured motion were evaluated based on aspects of the rats’ intersegmental coordination and power spectrum density (PSD). These characteristics were compared with those of the human bipedal posture. The intersegmental coordination of the standing rats included two components that were similar to that of standing humans: center of mass and trunk motion. The rats’ PSD showed a peak at approximately 1.8 Hz and the pattern of the PSD under the peak frequency was similar to that of the human PSD. However, the frequencies were five times higher in rats than in humans. Based on the analysis of the rats’ bipedal standing motion, there were some common characteristics between rat and human standing motions. Thus, using standing rats is expected to be a powerful tool to reveal the neural basis of postural control. PMID:29244818

Longitudinal performance of a surgically implanted neuroprosthesis for lower-extremity exercise, standing, and transfers after spinal cord injury.

PubMed

Triolo, Ronald J; Bailey, Stephanie Nogan; Miller, Michael E; Rohde, Loretta M; Anderson, James S; Davis, John A; Abbas, James J; DiPonio, Lisa A; Forrest, George P; Gater, David R; Yang, Lynda J

2012-05-01

To investigate the longitudinal performance of a surgically implanted neuroprosthesis for lower-extremity exercise, standing, and transfers after spinal cord injury. Case series. Research or outpatient physical therapy departments of 4 academic hospitals. Subjects (N=15) with thoracic or low cervical level spinal cord injuries who had received the 8-channel neuroprosthesis for exercise and standing. After completing rehabilitation with the device, the subjects were discharged to unrestricted home use of the system. A series of assessments were performed before discharge and at a follow-up appointment approximately 1 year later. Neuroprosthesis usage, maximum standing time, body weight support, knee strength, knee fatigue index, electrode stability, and component survivability. Levels of maximum standing time, body weight support, knee strength, and knee fatigue index were not statistically different from discharge to follow-up (P>.05). Additionally, neuroprosthesis usage was consistent with subjects choosing to use the system on approximately half of the days during each monitoring period. Although the number of hours using the neuroprosthesis remained constant, subjects shifted their usage to more functional standing versus more maintenance exercise, suggesting that the subjects incorporated the neuroprosthesis into their lives. Safety and reliability of the system were demonstrated by electrode stability and a high component survivability rate (>90%). This group of 15 subjects is the largest cohort of implanted lower-extremity neuroprosthetic exercise and standing system users. The safety and efficiency data from this group, and acceptance of the neuroprosthesis as demonstrated by continued usage, indicate that future efforts toward commercialization of a similar device may be warranted. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Causation between occupational prolonged standing time during progestation and pregnancy related complications].

PubMed

Weng, Ting-ting; Xu, Ye-qing; Yan, Shuang-qin; Pan, Wei-jun; Tao, Fang-biao

2013-06-01

To describe the epidemiological characteristics of profession related long-standing behavior during preconception and progestation, and to probe the relationship between prolonged standing jobs and the common pregnancy related complications among pregnant women, in Ma' anshan city,Anhui province. In this cohort study, subjects who had their first antenatal examination at Ma' anshan Maternal and Child Care Centers were recruited under informed consent, from October 2008 to October 2010. All the information were collected through questionnaires in the first, second and third trimesters respectively. Three questionnaires were filled in by subjects under the guidance of healthcare takers. In the study, the 75(th) percentile of prolonged-standing times were 4.0 h/d and 3.0 h/d respectively in preconception and progestation. The characteristics of pregnant women with low social/economic status, prone to be involved in stand-long occupation. Results in logistic regression analysis, prolonged-standing jobs during preconception was the risk factor of pregnancy-induced hypertension and severe anemia. The adjusted odds ratios were 2.05 (95%CI:1.26-3.31) and 1.38(95%CI:1.03-1.85)respectively. Prolonged standing jobs appeared to be common occupational exposure to and risks of both pregnant woman and their fetus. Exposure to these kinds of jobs during preconception could increase the risk of pregnancy-induced hypertension and severe anemia. In order to promote maternal health programs, all the related occupational risk factors should be valued and avoided during preconception and pregnancy.

Effect of obesity on posture and hip joint moments during a standing task, and trunk forward flexion motion.

PubMed

Gilleard, W; Smith, T

2007-02-01

Effects of obesity on trunk forward flexion motion in sitting and standing, and postural adaptations and hip joint moment for a standing work task. Cross-sectional comparison of obese and normal weight groups. Ten obese subjects (waist girth 121.2+/-16.8 cm, body mass index (BMI) 38.9+/-6.6 kg m(-2)) and 10 age- and height-matched normal weight subjects (waist girth 79.6+/-6.4 cm, BMI 21.7+/-1.5 kg m(-2)). Trunk motion during seated and standing forward flexion, and trunk posture, hip joint moment and hip-to-bench distance during a simulated standing work task were recorded. Forward flexion motion of the thoracic segment and thoracolumbar spine was decreased for the obese group with no change in pelvic segment and hip joint motion. Obese subjects showed a more flexed trunk posture and increased hip joint moment and hip-to-bench distance for a simulated standing work task. Decreased range of forward flexion motion, differing effects within the trunk, altered posture during a standing work task and concomitant increases in hip joint moment give insight into the aetiology of functional decrements and musculoskeletal pain seen in obesity.

Impacts of harvesting and postharvest treatments on soil bulk density, soil strength, and ealry growth of Pinus taeda in the Gulf Coastal Plain: a long-term soil productivity affiliated study

Treesearch

Mason C. Carter; Thomas J. Dean; Ziyin Wang; Ray A. Newbold

2006-01-01

At four sites in the Gulf Coastal Plain, mechanical whole-tree harvesting (MWT) removed from biomass and nutrients than hand-fell bole-only harvesting (HFBO). Soil compaction and loblolly pine (Pinus taeda L.) regeneration growth varied among sites. At one location, MWT increased soil bulk density by 0.1 Mgm-3, from 1.14 to 1....

Trunk acceleration for neuroprosthetic control of standing: a pilot study.

PubMed

Nataraj, Raviraj; Audu, Musa L; Kirsch, Robert F; Triolo, Ronald J

2012-02-01

This pilot study investigated the potential of using trunk acceleration feedback control of center of pressure (COP) against postural disturbances with a standing neuroprosthesis following paralysis. Artificial neural networks (ANNs) were trained to use three-dimensional trunk acceleration as input to predict changes in COP for able-bodied subjects undergoing perturbations during bipedal stance. Correlation coefficients between ANN predictions and actual COP ranged from 0.67 to 0.77. An ANN trained across all subject-normalized data was used to drive feedback control of ankle muscle excitation levels for a computer model representing a standing neuroprosthesis user. Feedback control reduced average upper-body loading during perturbation onset and recovery by 42% and peak loading by 29% compared with optimal, constant excitation.

Effects of canopy treatments on early growth of planted longleaf pine seedlings and ground vegetation in North Carolina: a preliminary study

Treesearch

Huifeng Hu; Benjamin O. Knapp; G. Geoff Wang; Joan L. Walker

2013-01-01

We installed a field experiment to support the development of protocols to restore longleaf pine (Pinus palustris Mill.) to existing mature loblolly pine (P. taeda L.) stands at Camp Lejeune, NC. Seven canopy treatments included four uniform and three gap treatments. The four uniform treatments were defined by target residual basal...

Documentation and user guides for SPBLOB: a computer simulation model of the join population dynamics for loblolly pine and the southern pine beetle

Treesearch

John Bishir; James Roberds; Brian Strom; Xiaohai Wan

2009-01-01

SPLOB is a computer simulation model for the interaction between loblolly pine (Pinus taeda L.), the economically most important forest crop in the United States, and the southern pine beetle (SPB: Dendroctonus frontalis Zimm.), the major insect pest for this species. The model simulates loblolly pine stands from time of planting...

Twenty years of natural loblolly and shortleaf pine seed production on the Crossett Experimental Forest in southeastern Arkansas

Treesearch

Michael D. Cain; Michael G. Shelton

2001-01-01

Loblolly and shortleaf pine (Pinus taeda L. and P. chinata Mill., respectively) seed crops were monitored for 20 consecutive years (1980-1981 through 1999-2000) using seed-collection traps in natural stands on the Upper Coastal Plain of southeastern Arkansas. Each seed-collection period began on October 1 and continued...

Laparoscopic cholecystectomy poses physical injury risk to surgeons: analysis of hand technique and standing position.

PubMed

Youssef, Yassar; Lee, Gyusung; Godinez, Carlos; Sutton, Erica; Klein, Rosemary V; George, Ivan M; Seagull, F Jacob; Park, Adrian

2011-07-01

This study compares surgical techniques and surgeon's standing position during laparoscopic cholecystectomy (LC), investigating each with respect to surgeons' learning, performance, and ergonomics. Little homogeneity exists in LC performance and training. Variations in standing position (side-standing technique vs. between-standing technique) and hand technique (one-handed vs. two-handed) exist. Thirty-two LC procedures performed on a virtual reality simulator were video-recorded and analyzed. Each subject performed four different procedures: one-handed/side-standing, one-handed/between-standing, two-handed/side-standing, and two-handed/between-standing. Physical ergonomics were evaluated using Rapid Upper Limb Assessment (RULA). Mental workload assessment was acquired with the National Aeronautics and Space Administration-Task Load Index (NASA-TLX). Virtual reality (VR) simulator-generated performance evaluation and a subjective survey were analyzed. RULA scores were consistently lower (indicating better ergonomics) for the between-standing technique and higher (indicating worse ergonomics) for the side-standing technique, regardless of whether one- or two-handed. Anatomical scores overall showed side-standing to have a detrimental effect on the upper arms and trunk. The NASA-TLX showed significant association between the side-standing position and high physical demand, effort, and frustration (p<0.05). The two-handed technique in the side-standing position required more effort than the one-handed (p<0.05). No difference in operative time or complication rate was demonstrated among the four procedures. The two-handed/between-standing method was chosen as the best procedure to teach and standardize. Laparoscopic cholecystectomy poses a risk of physical injury to the surgeon. As LC is currently commonly performed in the United States, the left side-standing position may lead to increased physical demand and effort, resulting in ergonomically unsound conditions for

Effects of sitting versus standing and scanner type on cashiers.

PubMed

Lehman, K R; Psihogios, J P; Meulenbroek, R G

2001-06-10

In the retail supermarket industry where cashiers perform repetitive, light manual material-handling tasks when scanning and handling products, reports of musculoskeletal disorders and discomfort are high. Ergonomics tradeoffs exist between sitting and standing postures, which are further confounded by the checkstand design and point-of-sale technology, such as the scanner. A laboratory experiment study was conducted to understand the effects of working position (sitting versus standing) and scanner type (bi-optic versus single window) on muscle activity, upper limb and spinal posture, and subjective preference of cashiers. Ten cashiers from a Dutch retailer participated in the study. Cashiers exhibited lower muscle activity in the neck and shoulders when standing and using a bi-optic scanner. Shoulder abduction was also less for standing conditions. In addition, all cashiers preferred using the bi-optic scanner with mixed preferences for sitting (n = 6) and standing (n = 4). Static loading of the muscles was relatively high compared with benchmarks, suggesting that during the task of scanning, cashiers may not have adequate recovery time to prevent fatigue. It is recommended that retailers integrate bi-optic scanners into standing checkstands to minimize postural stress, fatigue and discomfort in cashiers.

Changes in muscle activation patterns and subjective low back pain ratings during prolonged standing in response to an exercise intervention.

PubMed

Nelson-Wong, Erika; Callaghan, Jack P

2010-12-01

Low back pain (LBP) development has been associated with occupational standing. Increased hip and trunk muscle co-activation is considered to be predisposing for LBP development during standing in previously asymptomatic individuals. The purpose of this work was to investigate muscle activation and LBP responses to a prescribed exercise program. Pain-developing (PD) individuals were expected to have decreased LBP and muscle co-activation following exercise intervention. Electromyography (EMG) data were recorded from trunk and hip muscle groups during 2-h of standing. An increase of >10mm on visual analog scale (VAS) during standing was threshold for PD categorization. Participants were assigned to progressive exercise program with weekly supervision or control (usual activity) for 4 weeks then re-tested. Forty percent were categorized as PD on day 1, VAS=24.2 (±4.0)mm. PD exercisers (PDEX) had lower VAS scores (8.93±3.66 mm) than PD control (PDCON) (16.5±6.3 mm) on day 2 (p=0.007). Male PDEX had decreased gluteus medius co-activation levels (p<0.05) on day 2. The exercise program proved beneficial in reducing LBP during standing. There were changes in muscle activation patterns previously associated with LBP. Predisposing factors for LBP during standing were shown to change positively with appropriate exercise intervention. Copyright © 2010 Elsevier Ltd. All rights reserved.

Difference in caloric expenditure in sitting versus standing desks.

PubMed

Reiff, Christopher; Marlatt, Kara; Dengel, Donald R

2012-09-01

Traditional desks require students to sit; however, recently schools have provided students with nontraditional standing desks. The purpose of this study was to investigate differences in caloric expenditure of young adults while sitting at a standard classroom desk and standing at a nontraditional standing classroom desk. Twenty (10 male/10 female) young (22.8 ± 1.9 y), healthy participants reported to the laboratory between the hours of 7:00 AM and 2:00 PM following a 12-h fast and 48-h break in exercise. Participants were randomly assigned to perform a series of mathematical problems either sitting at a normal classroom desk or standing at a nontraditional standing desk. Inspired and expired gases were collected for 45-min for the determination of oxygen consumption (VO2), carbon dioxide production (VCO2), and minute ventilation (VE) using a metabolic gas system. There were significant increases from sitting to standing in VO2 (0.22 ± 0.05 vs. 0.28 ± 0.05 L·min-1, P ≤ .0001), VCO2 (0.18 ± 0.05 vs. 0.24 ± 0.050 L·min-1, P ≤ .0001), VE (7.72 ± 0.67 vs. 9.41 ± 1.20 L·min-1, P ≤ .0001), and kilocalories expended per minute (1.36 ± 0.20 kcal/min, P ≤ .0001 vs. 1.02 ± 0.22 kcal/min, P ≤ .0001). Results indicate a significant increase in caloric expenditure in subjects that were standing at a standing classroom desk compared with sitting at a standard classroom desk.

Improved oxygenation during standing performance of deep breathing exercises with positive expiratory pressure after cardiac surgery: A randomized controlled trial.

PubMed

Pettersson, Henrik; Faager, Gun; Westerdahl, Elisabeth

2015-09-01

Breathing exercises after cardiac surgery are often performed in a sitting position. It is unknown whether oxygenation would be better in the standing position. The aim of this study was to evaluate oxygenation and subjective breathing ability during sitting vs standing performance of deep breathing exercises on the second day after cardiac surgery. Patients undergoing coronary artery bypass grafting (n = 189) were randomized to sitting (controls) or standing. Both groups performed 3 × 10 deep breaths with a positive expiratory pressure device. Peripheral oxygen saturation was measured before, directly after, and 15 min after the intervention. Subjective breathing ability, blood pressure, heart rate, and pain were assessed. Oxygenation improved significantly in the standing group compared with controls directly after the breathing exercises (p < 0.001) and after 15 min rest (p = 0.027). The standing group reported better deep breathing ability compared with controls (p = 0.004). A slightly increased heart rate was found in the standing group (p = 0.047). After cardiac surgery, breathing exercises with positive expiratory pressure, performed in a standing position, significantly improved oxygenation and subjective breathing ability compared with sitting performance. Performance of breathing exercises in the standing position is feasible and could be a valuable treatment for patients with postoperative hypoxaemia.

Transcriptional control of monolignol biosynthesis in Pinus taeda: factors affecting monolignol ratios and carbon allocation in phenylpropanoid metabolism

NASA Technical Reports Server (NTRS)

Anterola, Aldwin M.; Jeon, Jae-Heung; Davin, Laurence B.; Lewis, Norman G.

2002-01-01

Transcriptional profiling of the phenylpropanoid pathway in Pinus taeda cell suspension cultures was carried out using quantitative real time PCR analyses of all known genes involved in the biosynthesis of the two monolignols, p-coumaryl and coniferyl alcohols (lignin/lignan precursors). When the cells were transferred to a medium containing 8% sucrose and 20 mm potassium iodide, the monolignol/phenylpropanoid pathway was induced, and transcript levels for phenylalanine ammonia lyase, cinnamate 4-hydroxylase, p-coumarate 3-hydroxylase, 4-coumarate:CoA ligase, caffeoyl-CoA O-methyltransferase, cinnamoyl-CoA reductase, and cinnamyl alcohol dehydrogenase were coordinately up-regulated. Provision of increasing levels of exogenously supplied Phe to saturating levels (40 mm) to the induction medium resulted in further up-regulation of their transcript levels in the P. taeda cell cultures; this in turn was accompanied by considerable increases in both p-coumaryl and coniferyl alcohol formation and excretion. By contrast, transcript levels for both cinnamate 4-hydroxylase and p-coumarate 3-hydroxylase were only slightly up-regulated. These data, when considered together with metabolic profiling results and genetic manipulation of various plant species, reveal that carbon allocation to the pathway and its differential distribution into the two monolignols is controlled by Phe supply and differential modulation of cinnamate 4-hydroxylase and p-coumarate 3-hydroxylase activities, respectively. The coordinated up-regulation of phenylalanine ammonia lyase, 4-coumarate:CoA ligase, caffeoyl-CoA O-methyltransferase, cinnamoyl-CoA reductase and cinnamyl alcohol dehydrogenase in the presence of increasing concentrations of Phe also indicates that these steps are not truly rate-limiting, because they are modulated according to metabolic demand. Finally, the transcript profile of a putative acid/ester O-methyltransferase, proposed as an alternative catalyst for O-methylation leading

Transcriptional control of monolignol biosynthesis in Pinus taeda: factors affecting monolignol ratios and carbon allocation in phenylpropanoid metabolism.

PubMed

Anterola, Aldwin M; Jeon, Jae-Heung; Davin, Laurence B; Lewis, Norman G

2002-05-24

Transcriptional profiling of the phenylpropanoid pathway in Pinus taeda cell suspension cultures was carried out using quantitative real time PCR analyses of all known genes involved in the biosynthesis of the two monolignols, p-coumaryl and coniferyl alcohols (lignin/lignan precursors). When the cells were transferred to a medium containing 8% sucrose and 20 mm potassium iodide, the monolignol/phenylpropanoid pathway was induced, and transcript levels for phenylalanine ammonia lyase, cinnamate 4-hydroxylase, p-coumarate 3-hydroxylase, 4-coumarate:CoA ligase, caffeoyl-CoA O-methyltransferase, cinnamoyl-CoA reductase, and cinnamyl alcohol dehydrogenase were coordinately up-regulated. Provision of increasing levels of exogenously supplied Phe to saturating levels (40 mm) to the induction medium resulted in further up-regulation of their transcript levels in the P. taeda cell cultures; this in turn was accompanied by considerable increases in both p-coumaryl and coniferyl alcohol formation and excretion. By contrast, transcript levels for both cinnamate 4-hydroxylase and p-coumarate 3-hydroxylase were only slightly up-regulated. These data, when considered together with metabolic profiling results and genetic manipulation of various plant species, reveal that carbon allocation to the pathway and its differential distribution into the two monolignols is controlled by Phe supply and differential modulation of cinnamate 4-hydroxylase and p-coumarate 3-hydroxylase activities, respectively. The coordinated up-regulation of phenylalanine ammonia lyase, 4-coumarate:CoA ligase, caffeoyl-CoA O-methyltransferase, cinnamoyl-CoA reductase and cinnamyl alcohol dehydrogenase in the presence of increasing concentrations of Phe also indicates that these steps are not truly rate-limiting, because they are modulated according to metabolic demand. Finally, the transcript profile of a putative acid/ester O-methyltransferase, proposed as an alternative catalyst for O-methylation leading

Inverted Pendulum Standing Apparatus for Investigating Closed-Loop Control of Ankle Joint Muscle Contractions during Functional Electrical Stimulation.

PubMed

Tan, John F; Masani, Kei; Vette, Albert H; Zariffa, José; Robinson, Mark; Lynch, Cheryl; Popovic, Milos R

2014-01-01

The restoration of arm-free standing in individuals with paraplegia can be facilitated via functional electrical stimulation (FES). In developing adequate control strategies for FES systems, it remains challenging to test the performance of a particular control scheme on human subjects. In this study, we propose a testing platform for developing effective control strategies for a closed-loop FES system for standing. The Inverted Pendulum Standing Apparatus (IPSA) is a mechanical inverted pendulum, whose angular position is determined by the subject's ankle joint angle as controlled by the FES system while having the subject's body fixed in a standing frame. This approach provides a setup that is safe, prevents falling, and enables a research and design team to rigorously test various closed-loop controlled FES systems applied to the ankle joints. To demonstrate the feasibility of using the IPSA, we conducted a case series that employed the device for studying FES closed-loop controllers for regulating ankle joint kinematics during standing. The utilized FES system stimulated, in able-bodied volunteers, the plantarflexors as they prevent toppling during standing. Four different conditions were compared, and we were able to show unique performance of each condition using the IPSA. We concluded that the IPSA is a useful tool for developing and testing closed-loop controlled FES systems for regulating ankle joint position during standing.

Inverted Pendulum Standing Apparatus for Investigating Closed-Loop Control of Ankle Joint Muscle Contractions during Functional Electrical Stimulation

PubMed Central

Tan, John F.; Masani, Kei; Vette, Albert H.; Zariffa, José; Robinson, Mark; Lynch, Cheryl; Popovic, Milos R.

2014-01-01

The restoration of arm-free standing in individuals with paraplegia can be facilitated via functional electrical stimulation (FES). In developing adequate control strategies for FES systems, it remains challenging to test the performance of a particular control scheme on human subjects. In this study, we propose a testing platform for developing effective control strategies for a closed-loop FES system for standing. The Inverted Pendulum Standing Apparatus (IPSA) is a mechanical inverted pendulum, whose angular position is determined by the subject's ankle joint angle as controlled by the FES system while having the subject's body fixed in a standing frame. This approach provides a setup that is safe, prevents falling, and enables a research and design team to rigorously test various closed-loop controlled FES systems applied to the ankle joints. To demonstrate the feasibility of using the IPSA, we conducted a case series that employed the device for studying FES closed-loop controllers for regulating ankle joint kinematics during standing. The utilized FES system stimulated, in able-bodied volunteers, the plantarflexors as they prevent toppling during standing. Four different conditions were compared, and we were able to show unique performance of each condition using the IPSA. We concluded that the IPSA is a useful tool for developing and testing closed-loop controlled FES systems for regulating ankle joint position during standing. PMID:27350992

Hypoxia-induced changes in standing balance.

PubMed

Wagner, Linsey S; Oakley, Sarah R; Vang, Pao; Noble, Brie N; Cevette, Michael J; Stepanek, Jan P

2011-05-01

A few studies in the literature have reported postural changes with hypoxia, but none have quantified the magnitude of change. Further understanding of this condition could have implications for patients at risk for falls, individuals undergoing acute altitude exposure, and pilots and commercial passengers. The objective of this study was to evaluate the effect of different levels of hypoxia (oxygen nitrogen mixtures) on postural standing balance using the computerized dynamic posturography (CDP) system. This improves upon previous protocols by manipulating vision and standing balance with a sway-referenced visual field and/or platform. Additionally, normative data were available for comparison with the cumulative test scores and scores for each condition. Altitude hypoxia was simulated by use of admixing nitrogen to the breathing gas to achieve equivalent altitudes of 1524 m, 2438 m, and 3048 m. Subjects were evaluated using the CDP system. Subjects showed an overall trend toward decreased performance at higher simulated altitudes consistent with the initial hypothesis. Composite standing balance sway scores for the sensory organization subtest of CDP were decreased compared to baseline for simulated altitudes as low as 2438 m (mean sway scores: 81.92 at baseline; 81.85 at 1524 m; 79.15 at 2438 m; 79.15 at 3048 m). Reaction times to unexpected movements in the support surface for the motor control subtest (MCT) increased compared to baseline (mean composite scores: 133.3 at baseline; 135.9 ms at 1524 m; 138.0 ms at 2438 m; 140.9 ms at 3048 m). The CDP testing provided a reliable objective measurement of degradation of balance under hypoxic conditions.

Prescribed Winter Burns Can Reduce the Growth of Nine-Year-Old Loblolly Pines

Treesearch

Michael D. Cain

1985-01-01

Prescribed winter burning was done in a precommercially thinned, 9-year-old, natural stand of loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.). Growth and survival of 174 loblolly pines were monitored one growing season after this burning. Mortality was highest for pines with less than 2 inches groundline...

Response of Soil Bulk Density and Mineral Nitrogen to Harvesting and Cultural Treatments

Treesearch

Minyi Zhou; Mason C. Carter; Thomas J. Dean

1998-01-01

The interactive effects of harvest intensity, site preparation, and fertilization on soil compaction and nitrogen mineralization were examined in a loblolly pine (Pinus taeda L.) stand growing on a sandy, well-drained soil in eastern Texas. The experimental design was 2 by 2 by 2 factorial, consisting of two harvesting treatments (mechanical whole-...

Seasonal Fine-Root Carbohydrate and Growth Relations of Plantation Loblolly Pine After Thinning and Fertilization

Treesearch

Eric A. Kuehler; Mary Anne Sword; C. Dan Andries

1999-01-01

In 1989, two levels each of stand density and fertilization were established in an 8-year-old loblolly pine (Pinus taeda L.) plantation. In March 1995, treatments were reapplied, and root elongation and carbohydrate concentrations were monitored for 2 years. Our objective was to evaluate relationships between seasonal root growth and carbohydrate...

Thinning Guidelines For Loblolly Pine Plantations in Eastern Texas Based on Alternative Management Criteria

Treesearch

Charles T. Stiff; William F. Stansfield

2004-01-01

Separate thinning guidelines were developed for maximizing land expectation value (LEV), present net worth (PNW), and total sawlog yield (TSY) of existing and future loblolly pine (Pinus taeda L.) plantations in eastern Texas. The guidelines were created using data from simulated stands which were thinned one time during their rotation using a...

Weighted linear regression using D2H and D2 as the independent variables

Treesearch

Hans T. Schreuder; Michael S. Williams

1998-01-01

Several error structures for weighted regression equations used for predicting volume were examined for 2 large data sets of felled and standing loblolly pine trees (Pinus taeda L.). The generally accepted model with variance of error proportional to the value of the covariate squared ( D2H = diameter squared times height or D...

The Effect of Large Applications of Nutrients From Organic Waste on Biomass Allocation and Allometric Relations in Loblolly Pine

Treesearch

Scott D. Roberts; Patrick D. Gerard

2004-01-01

We applied broiler litter to an 8-year-old precommercially thinned loblolly pine (Pinus taeda L.) stand at 0, 5.6, and 23 Mg ha-1 , supplying 0, 200, and 800 kg N ha-1. A destructive harvest was implemented two growing seasons following litter application to evaluate treatment impacts on patterns of...

Dispersal and viability of seeds from cones in tops of harvested loblolly pines

Treesearch

Michael G. Shelton; Michael D. Cain

2001-01-01

Seed supply is one of the most important determinants of successful natural regeneration. We conducted a study to determine the potential contribution of cones in the tops of harvested loblolly pines (Pinus taeda L.) to the stand's seed supply if trees were felled after seed maturation but before dispersal. Closed cones, collected in...

Long term growth responses of loblolly pine to optimal nutrient and water resource availability

Treesearch

Timothy J. Albaugh; H. Lee Allen; Phillip M. Dougherty; Kurt H. Johnsen

2004-01-01

A factorial combination of four treatments (control (CW), optimal growing season water availability (IW), optimum nutrient availability (FW), and combined optimum water and nutrient availability (FIW)) in four replications were initiated in an 8-year- old Pinus taeda stand growing on a droughty, nutrient-poor, sandy site in Scotland County, NC and...

Effect of silvicultural practice and wood type on loblolly pine particleboard and medium density fiberboard properties

Treesearch

Todd F. Shupe; Chung Y. Hse; Elvin T. Choong; Leslie H. Groom

1999-01-01

he objective of this study was to determine the effect of five different silvicultural strategies and wood type on mechanical and physical properties of loblolly pine (Pinus taeda L.) particleboard and fiberboard. The furnish was prepared in an unconventional manner from innerwood and outerwood veneer for each stand. Modulus of rupture (MOR)...

Silvicultural systems and red-cockaded woodpecker management: another perspective

Treesearch

Larry D. Hedrick; Robert G. Hooper; Dennis L. Krusac; Joseph M. Dabney

1998-01-01

In 1996 Rudolph and Conner maintained that a modified even-aged silvicultural system using irregular shelterwood as the method of regenerating new stands provides greater benefits for red-cockaded woodpeckers (Picoides borealis) than uneven-aged systems. Their argument was confined to loblolly (Pinus taeda) and shortleaf (P. ecbinata) pine forest types and emphasized...

Growth and Yield Relative to Competition for Loblolly Pine Plantations to Midrotation- A Southeastern United States Regional Study

Treesearch

James H. Miller; Bruce R. Zutter; Shepard M. Zedaker; M. Boyd Edwards; Ray A. Newbold

2003-01-01

Loblolly pine (Pinus taeda L.) plantations were studied across 13 southeastern sites grown for 1.5 yr with near-complete control of woody, herbaceous, and woody plus herbaceous components during the first 3-5 yr. This multiple objective experiment (the COMProject) documents stand dynamics at the extreme corners of the response surface that...

Dynamics of planted cherrybark oak seedlings and yellow-poplar from seed following a regeneration clearcut

Treesearch

Wayne K. Clatterbuck

2011-01-01

A bottomland loblolly pine (Pinus taeda) stand originating from an early 1940s planting on a minor stream bottom of the Coastal Plain in west Tennessee was harvested in 1992 and allowed to regenerate to hardwoods. Although the pines had been planted, a few naturally regenerated yellow-poplar (Liriodendron tulipifera) and sweetgum...

Exploring the loblolly pine (Pinus taeda L.) genome by BAC sequencing and Cot analysis.

PubMed

Perera, Dinum; Magbanua, Zenaida V; Thummasuwan, Supaphan; Mukherjee, Dipaloke; Arick, Mark; Chouvarine, Philippe; Nairn, Campbell J; Schmutz, Jeremy; Grimwood, Jane; Dean, Jeffrey F D; Peterson, Daniel G

2018-07-15

Loblolly pine (LP; Pinus taeda L.) is an economically and ecologically important tree in the southeastern U.S. To advance understanding of the loblolly pine (LP; Pinus taeda L.) genome, we sequenced and analyzed 100 BAC clones and performed a Cot analysis. The Cot analysis indicates that the genome is composed of 57, 24, and 10% highly-repetitive, moderately-repetitive, and single/low-copy sequences, respectively (the remaining 9% of the genome is a combination of fold back and damaged DNA). Although single/low-copy DNA only accounts for 10% of the LP genome, the amount of single/low-copy DNA in LP is still 14 times the size of the Arabidopsis genome. Since gene numbers in LP are similar to those in Arabidopsis, much of the single/low-copy DNA of LP would appear to be composed of DNA that is both gene- and repeat-poor. Macroarrays prepared from a LP bacterial artificial chromosome (BAC) library were hybridized with probes designed from cell wall synthesis/wood development cDNAs, and 50 of the "targeted" clones were selected for further analysis. An additional 25 clones were selected because they contained few repeats, while 25 more clones were selected at random. The 100 BAC clones were Sanger sequenced and assembled. Of the targeted BACs, 80% contained all or part of the cDNA used to target them. One targeted BAC was found to contain fungal DNA and was eliminated from further analysis. Combinations of similarity-based and ab initio gene prediction approaches were utilized to identify and characterize potential coding regions in the 99 BACs containing LP DNA. From this analysis, we identified 154 gene models (GMs) representing both putative protein-coding genes and likely pseudogenes. Ten of the GMs (all of which were specifically targeted) had enough support to be classified as intact genes. Interestingly, the 154 GMs had statistically indistinguishable (α = 0.05) distributions in the targeted and random BAC clones (15.18 and 12.61 GM/Mb, respectively

Referent control and motor equivalence of reaching from standing

PubMed Central

Tomita, Yosuke; Feldman, Anatol G.

2016-01-01

Motor actions may result from central changes in the referent body configuration, defined as the body posture at which muscles begin to be activated or deactivated. The actual body configuration deviates from the referent configuration, particularly because of body inertia and environmental forces. Within these constraints, the system tends to minimize the difference between these configurations. For pointing movement, this strategy can be expressed as the tendency to minimize the difference between the referent trajectory (RT) and actual trajectory (QT) of the effector (hand). This process may underlie motor equivalent behavior that maintains the pointing trajectory regardless of the number of body segments involved. We tested the hypothesis that the minimization process is used to produce pointing in standing subjects. With eyes closed, 10 subjects reached from a standing position to a remembered target located beyond arm length. In randomly chosen trials, hip flexion was unexpectedly prevented, forcing subjects to take a step during pointing to prevent falling. The task was repeated when subjects were instructed to intentionally take a step during pointing. In most cases, reaching accuracy and trajectory curvature were preserved due to adaptive condition-specific changes in interjoint coordination. Results suggest that referent control and the minimization process associated with it may underlie motor equivalence in pointing. NEW & NOTEWORTHY Motor actions may result from minimization of the deflection of the actual body configuration from the centrally specified referent body configuration, in the limits of neuromuscular and environmental constraints. The minimization process may maintain reaching trajectory and accuracy regardless of the number of body segments involved (motor equivalence), as confirmed in this study of reaching from standing in young healthy individuals. Results suggest that the referent control process may underlie motor equivalence in

A drive system to add standing mobility to a manual standing wheelchair.

PubMed

Nickel, Eric; Hansen, Andrew; Pearlman, Jonathan; Goldish, Gary

2016-05-16

Current manual standing wheelchairs are not mobile in the standing position. The addition of standing mobility may lead to improved health and function for the user and may increase utilization of standing wheelchairs. In this project, a chain drive system was fitted to a manual standing wheelchair, adding mobility in the standing position. The hand rims are accessible from both seated and standing positions. The prototype uses 16-inch drive wheels in front with casters in the rear. Additional anterior casters are elevated when seated for navigating obstacles and then descend when standing to create a six-wheeled base with extended anterior support. Stability testing shows the center of pressure remains within the base of support when leaning to the sides or front in both seated and standing positions. Four veterans with spinal cord injury provided feedback on the design and reported that mobility during standing was very important or extremely important to them. The veterans liked the perceived stability and mobility of the prototype and provided feedback for future refinements. For example, reducing the overall width (width from hand rim to hand rim) and weight could make this system more functional for users.

Standing Tall: The Benefits of Standing Devices

ERIC Educational Resources Information Center

Warner, Mark P.

2007-01-01

In the author's opinion as a pediatric physical therapist, with the exception of a wheelchair, there is no other piece of assistive technology that is more beneficial to children and adults with special needs than a standing device. Postural symmetry during standing and walking activities is extremely important for everyone. Very few children…

Differences in Trunk Accelerometry Between Frail and Nonfrail Elderly Persons in Sit-to-Stand and Stand-to-Sit Transitions Based on a Mobile Inertial Sensor.

PubMed

Galán-Mercant, Alejandro; Cuesta-Vargas, Antonio I

2013-08-16

Clinical frailty syndrome is a common geriatric syndrome, which is characterized by physiological reserve decreases and increased vulnerability. The changes associated to ageing and frailties are associated to changes in gait characteristics and the basic functional capacities. Traditional clinical evaluation of Sit-to-Stand (Si-St) and Stand-to-Sit (St-Si) transition is based on visual observation of joint angle motion to describe alterations in coordination and movement pattern. The latest generation smartphones often include inertial sensors with subunits such as accelerometers and gyroscopes, which can detect acceleration. Firstly, to describe the variability of the accelerations, angular velocity, and displacement of the trunk during the Sit-to-Stand and Stand-to-Sit transitions in two groups of frail and physically active elderly persons, through instrumentation with the iPhone 4 smartphone. Secondly, we want to analyze the differences between the two study groups. A cross-sectional study that involved 30 subjects over 65 years, 14 frail and 16 fit subjects. The participants were classified with frail syndrome by the Fried criteria. Linear acceleration was measured along three orthogonal axes using the iPhone 4 accelerometer. Each subject performed up to three successive Si-St and St-Si postural transitions using a standard chair with armrest. Significant differences were found between the two groups of frail and fit elderly persons in the accelerometry and angular displacement variables obtained in the kinematic readings of the trunk during both transitions. The inertial sensor fitted in the iPhone 4 is able to study and analyze the kinematics of the Si-St and St-Si transitions in frail and physically active elderly persons. The accelerometry values for the frail elderly are lower than for the physically active elderly, while variability in the readings for the frail elderly is also lower than for the control group.

Experimental Evaluation of Balance Prediction Models for Sit-to-Stand Movement in the Sagittal Plane

PubMed Central

Pena Cabra, Oscar David; Watanabe, Takashi

2013-01-01

Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius) variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal) condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary. PMID:24187580

Trunk Acceleration for Neuroprosthetic Control of Standing – a Pilot Study

PubMed Central

Audu, Musa L.; Kirsch, Robert F.; Triolo, Ronald J.

2013-01-01

This pilot study investigated the potential of using trunk acceleration feedback control of center of pressure (COP) against postural disturbances with a standing neuroprosthesis following paralysis. Artificial neural networks (ANNs) were trained to use three-dimensional trunk acceleration as input to predict changes in COP for able-bodied subjects undergoing perturbations during bipedal stance. Correlation coefficients between ANN predictions and actual COP ranged from 0.67 to 0.77. An ANN trained across all subject-normalized data was used to drive feedback control of ankle muscle excitation levels for a computer model representing a standing neuroprosthesis user. Feedback control reduced average upper-body loading during perturbation onset and recovery by 42% and peak loading by 29% compared to optimal, constant excitation. PMID:21975251

Testosterone Combined with Electrical Stimulation and Standing: Effect on Muscle and Bone

DTIC Science & Technology

2017-10-01

determined by the site physician and site PI. Research participants will be randomized into one of four groups : 1) Stand Training only; 2) Stand...Evaluate and assign participants to one of the four randomized groups at Kessler Ongoing Milestone Achieved: Kessler and JJPVAMC sites: Study...begins 4-6 Continue subject recruitment 4-30 Continue Screen potential participants 4-30 Evaluate and assign participants to one of the four

GPP in Loblolly Pine: A Monthly Comparison of Empirical and Process Models

Treesearch

Christopher Gough; John Seiler; Kurt Johnsen; David Arthur Sampson

2002-01-01

Monthly and yearly gross primary productivity (GPP) estimates derived from an empirical and two process based models (3PG and BIOMASS) were compared. Spatial and temporal variation in foliar gas photosynthesis was examined and used to develop GPP prediction models for fertilized nine-year-old loblolly pine (Pinus taeda) stands located in the North...

Maximum growth potential in loblolly pine: results from a 47-year-old spacing study in Hawaii

Treesearch

Lisa J. Samuelson; Thomas L. Eberhardt; John R. Butnor; Tom A. Stokes; Kurt H. Johnsen

2010-01-01

Growth, allocation to woody root biomass, wood properties, leaf physiology, and shoot morphology were examined in a 47-year-old loblolly pine (Pinus taeda L.) density trial located in Maui, Hawaii, to determine if stands continued to carry the high density, basal area, and volume reported at younger ages and to identify potential factors controlling...

Modeling thinning in east Texas loblolly and slash pine plantations

Treesearch

Dean W. Coble

2013-01-01

A new thinning model was proposed for loblolly pine (Pinus taeda L.) and slash pine (P. elliottii Engelm.) plantations in east Texas. The new model follows the index of suppression methodology introduced by Pienaar (1979). It was implemented in a new whole stand growth model for loblolly and slash pine plantations in east Texas (...

Importance of Coarse Woody Debris to Avian Communities in Loblolly Pine Forests

Treesearch

Steven M Lohr; Sidney A. Gauthreaux; John C. Kilgo

2002-01-01

To investigate the importance of standing (snags) aud down course woody debris (DCWD)) to bird communities in loblolly pine (Pinus taeda) forests, we compared breeding (1997-1999) und nonbreeding (1997- 1998, 1998-1999) responses of birds among two course woody debris (CWD) removal and control treatments. In each of four blocks, we estahblished four...

An overview of silvicultural influences on loblolly pine veneer-basedpanel properties

Treesearch

Todd F. Shupe; Chung Y. Hse; Elvin T. Choong

1999-01-01

Loblolly pine (Pinus taeda L.) harvested from five silviculturally different stands was used to manufacture 13-ply laminated veneer lumber (LVL) and 3-ply plywood. LVL panels were assembled as either all A-grade or all C-grade veneer. Plywood panels were produced according to four different veneer grade layups (AAA, ACA, ACC, and...

Stand-density study of spruce-hemlock stands in southeastern Alaska.

Treesearch

Donald J. DeMars

2000-01-01

The lack of growth and yield information for young even-aged western hemlock (Tsuga heterophylla(Raf.) Sarg.)-Sitka spruce (Picea sitchensis (Bong.) Carr.) stands in southeastern Alaska served as the impetus for a long-term stand-density study begun in 1974. The study has followed permanent growth plots in managed stands under...

The ambiguity of standing in standing devices: a qualitative interview study concerning children and parents experiences of the use of standing devices.

PubMed

Nordström, Birgitta; Näslund, Annika; Ekenberg, Lilly; Zingmark, Karin

2014-10-01

The aim of this study was to describe children's and parents' experiences of the significance of standing in a standing device. Individual interviews were performed with six children/teenagers (aged 7-19 years) and 14 parents. The interviews were transcribed and analyzed using a qualitative content analysis. The analysis resulted in the major theme, the duality of uprightness and the related themes: (1) the instrumental dimension of standing; (2) the social dimension of standing; and (3) the ambivalent dimension of standing. Each of the themes comprised several subthemes. There is an inherent duality related to the use of a standing device. Standing in a standing device was seen as a treatment of body structures and functions, as well as a possible source of pain. Standing was considered to influence freedom in activities and participation both positively and negatively. The parents experienced that standing influenced other peoples' views of their child, while the children experienced standing as a way to extend the body and as something that gave them benefits in some activities. Physiotherapists working with children should take into account both the social and physical dimensions of using a standing device and consider both the child's and the parents' views.

Unique Features of the Loblolly Pine (Pinus taeda L.) Megagenome Revealed Through Sequence Annotation

PubMed Central

Wegrzyn, Jill L.; Liechty, John D.; Stevens, Kristian A.; Wu, Le-Shin; Loopstra, Carol A.; Vasquez-Gross, Hans A.; Dougherty, William M.; Lin, Brian Y.; Zieve, Jacob J.; Martínez-García, Pedro J.; Holt, Carson; Yandell, Mark; Zimin, Aleksey V.; Yorke, James A.; Crepeau, Marc W.; Puiu, Daniela; Salzberg, Steven L.; de Jong, Pieter J.; Mockaitis, Keithanne; Main, Doreen; Langley, Charles H.; Neale, David B.

2014-01-01

The largest genus in the conifer family Pinaceae is Pinus, with over 100 species. The size and complexity of their genomes (∼20–40 Gb, 2n = 24) have delayed the arrival of a well-annotated reference sequence. In this study, we present the annotation of the first whole-genome shotgun assembly of loblolly pine (Pinus taeda L.), which comprises 20.1 Gb of sequence. The MAKER-P annotation pipeline combined evidence-based alignments and ab initio predictions to generate 50,172 gene models, of which 15,653 are classified as high confidence. Clustering these gene models with 13 other plant species resulted in 20,646 gene families, of which 1554 are predicted to be unique to conifers. Among the conifer gene families, 159 are composed exclusively of loblolly pine members. The gene models for loblolly pine have the highest median and mean intron lengths of 24 fully sequenced plant genomes. Conifer genomes are full of repetitive DNA, with the most significant contributions from long-terminal-repeat retrotransposons. In depth analysis of the tandem and interspersed repetitive content yielded a combined estimate of 82%. PMID:24653211

Reconstructing the spatial pattern of trees from routine stand examination measurements

USGS Publications Warehouse

Hanus, M.L.; Hann, D.W.; Marshall, D.D.

1998-01-01

Reconstruction of the spatial pattern of trees is important for the accurate visual display of unmapped stands. The proposed process for generating the spatial pattern is a nonsimple sequential inhibition process, with the inhibition zone proportionate to the scaled maximum crown width of an open-grown tree of the same species and same diameter at breast height as the subject tree. The results of this coordinate generation procedure are compared with mapped stem data from nine natural stands of Douglas-fir at two ages by the use of a transformed Ripley's K(d) function. The results of this comparison indicate that the proposed method, based on complete tree lists, successfully replicated the spatial patterns of the trees in all nine stands at both ages and over the range of distances examined. On the basis of these findings and the procedure's ability to model effects through time, the nonsimple sequential inhibition process has been chosen to generate tree coordinates in the VIZ4ST computer program for displaying forest stand structure in naturally regenerated young Douglas-fir stands. For. Sci.

Stand density, stand structure, and species composition in transition oak stands of northwestern Pennsylvania

Treesearch

S.L. Stout

1991-01-01

Transition stands, those containing species associated with both the northern hardwood and oak-hickory forest types, are important to forest diversity in northwestern Pennsylvania. These stands have high value for a variety of forest uses, including timber production, wildlife habitat, and aesthetics. Diameter distributions are characteristically stratified by species...

9. WEST SIDE, TEST STAND AND SUPERSTRUCTURE. TEST STAND 1B ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. WEST SIDE, TEST STAND AND SUPERSTRUCTURE. TEST STAND 1-B IN DISTANCE. Looking east. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

Investigation of cerebral hemodynamic changes during repeated sit-stand maneuver using functional near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Niu, Haijing; Li, Lin; Bhave, Gauri S.; Lin, Zi-jing; Tian, Fenghua; Khosrow, Behbehani; Zhang, Rong; Liu, Hanli

2011-03-01

The goal for this study is to examine cerebral autoregulation in response to a repeated sit-stand maneuver using both diffuse functional Near Infrared spectroscopy (fNIRS) and Transcranial Doppler sonography (TCD). While fNIRS can provide transient changes in hemodynamic response to such a physical action, TCD is a noninvasive transcranial method to detect the flow velocities in the basal or middle cerebral arteries (MCA). The initial phase of this study was to measure fNIRS signals from the forehead of subjects during the repeated sit-stand protocol and to understand the corresponding meaning of the detected signals. Also, we acquired preliminary data from simultaneous measurements of fNIRS and TCD during the sit-stand protocol so as to explore the technical difficulty of such an approach. Specifically, ten healthy adult subjects were enrolled to perform the planned protocol, and the fNIRS array probes with 4 sources and 10 detectors were placed on the subject's forehead to detect hemodynamic signal changes from the prefrontal cortex. The fNIRS results show that the oscillations of hemoglobin concentration were spatially global and temporally dynamic across the entire region of subject's forehead. The oscillation patterns in both hemoglobin concentrations and blood flow velocity seemed to follow one another; changes in oxy-hemoglobin concentration were much larger than those in deoxyhemoglobin concentration. These preliminary findings provide us with evidence that fNIRS is an appropriate means readily for studying cerebral hemodynamics and autoregulation during sit-stand maneuvers.

Primordial standing waves

NASA Astrophysics Data System (ADS)

Gubitosi, Giulia; Magueijo, João

2018-03-01

We consider the possibility that the primordial fluctuations (scalar and tensor) might have been standing waves at their moment of creation, whether or not they had a quantum origin. We lay down the general conditions for spatial translational invariance, and isolate the pieces of the most general such theory that comply with, or break translational symmetry. We find that, in order to characterize statistically translationally invariant standing waves, it is essential to consider the correlator ⟨c0(k )c0(k')⟩ in addition to the better known ⟨c0(k )c0†(k')⟩ [where c0(k ) are the complex amplitudes of traveling waves]. We then examine how the standard process of "squeezing" (responsible for converting traveling waves into standing waves while the fluctuations are outside the horizon) reacts to being fed primordial standing waves. For translationally invariant systems only one type of standing wave, with the correct temporal phase (the "sine wave"), survives squeezing. Primordial standing waves might therefore be invisible at late times—or not—depending on their phase. Theories with modified dispersion relations behave differently in this respect, since only standing waves with the opposite temporal phase survive at late times.

Mechanical Characteristics of Reflex Durign Upright Posture in Paralyzed Subjects

NASA Astrophysics Data System (ADS)

Kim, Yongchul; Youm, Youngil; Lee, Bumsuk; Kim, Youngho; Choi, Hyeonki

The characteristics of flexor reflexes have been investigated in the previous studies with human subjects who were seated or supine position. However, researchers did not describe how the spinal circuits are used in different hip angles for paralyzed subjects, such as the standing position with walker or cane. In upright posture the compatibility between a flexor reflex of leg and body balance is a special problem for lower limb injured subjects. Therefore, the purpose of this study was to investigate the effects of hip angle change on the flexor reflex evoked in standing paralyzed subjects supported by walker. In this study, six spinal cord injured and four stroke subjects were recruited through the inpatient physical therapy clinics of Korea national rehabilitation hospital. A single axis electronic goniometer was mounted on the lateral side of the hip joint of the impaired limb to record movements in the sagittal plane at this joint. The electronic goniometer was connected to a data acquisition system, through amplifiers to a computer. Since subject' posture influenced characteristics of the flexion reflex response, the subjects were supported in an upright posture by the help of parallelogram walder. Two series of tests were performed on each leg. The first series of the tests investigated the influence of hip angle during stationary standing posture on flexion reflex response. The hip angle was adjusted by the foot plate. The second examined the effect of the voluntary action of subject on swing motion during the gait. The electrically induced flexion reflex simultaneously produced the flexion of the hip, knee and dorsiflexion of the ankle enabling the swing phase of walking. Form the experimental results we observed that the reflex response of hip joint was largerwith the hip in the extended position than in the flexed position during standing posture. Under voluntary movement on flexion reflex during gaint, the peak hip angle induced by stimulation was

Characterization of yields for Pinus taeda genotypes at the half-sib, full-sib, and varietal levels of genetic improvement at two planting densities at age 5 in the upper coastal plain of Georgia

Treesearch

Derek Dougherty; Michael Kane; Robert Teskey; Richard Daniels; Jeff Wright

2012-01-01

Seedling deployment options for the establishment of operational Pinus taeda plantations in the Southeastern U.S. now include half-sib families, full-sib crosses, and varietals. In 2005, a study to evaluate the effects of genotype and density on yield and quality was established on a moderately well-drained upland site in the Upper Coastal Plain in...

Fuel accumulations in Piedmont loblolly pine plantations

Treesearch

Ernst V. Brender; W. Henry McNab; Shelton Williams

1976-01-01

Weight of minor vegetation under unthinned loblolly pine (Pinus taeda L.) plantations was closely related to stand age and basal area stocking. Weight of this vegetation peaked 3 years after clearcutting and planting, then diminished as the pine canopy became denser. Forest floor weight increased steadily through age 23, when it began to level off. Equilibrium forest...

The effects of planting density and cultural intensity on loblolly pine crown characteristics at age twelve

Treesearch

Madison Akers; Michael Kane; Robert Teskey; Richard Daniels; Dehai Zhao; Santosh Subedi

2012-01-01

Twelve-year old loblolly pine (Pinus taeda L.) stands were analyzed for the effects of planting density and cultural intensity on tree and crown attributes. Four study installations were located in the Piedmont and Upper Coastal Plain regions of the U.S. South. The treatments included six planting densities (740, 1480, 2220, 2960, 3700, 4440 trees...

Value of Tree Measurements Made at Age 5 Years for Predicting the Height and Diameter Growth at Age 25 Years in Loblolly Pine Plantations

Treesearch

Allan E. Tiarks; Calvin E. Meier; V. Clark Baldwin; James D. Haywood

1998-01-01

Early growth measurements Of pine plantations are often used to predict the productivity of the stand later in the rotation when assessing the effect Of management on productivity. A loblolly pine (Pinus taeda L.) study established at 35 locations (2 to 3 plots/location) was used to test the relationship between height measurements at age 5 years...

Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations

Treesearch

Gabriele Manoli; Jean-Christophe Domec; Kimberly Novick; Andrew C. Oishi; Asko Noormets; Marco Marani; Gabriel Katul

2016-01-01

Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, representmore than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m_2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be...

Modelling the limits on the response of net carbon exchange to fertilization in a south-eastern pine forest

Treesearch

Chun-Tai. Lai; G. Katul; J. Butnor; M. Siqueira; D. Ellsworth; C. Maier; Kurt Johnsen; S. Mickeand; R. Oren

2002-01-01

Using a combination of model simulations and detailed measurements at a hierarchy of scales conducted at a sandhills forest site, the effect of fertilization on net ecosystem exchange (NEE) and its components in 6-year-old Pinus taeda stands was quantified. The detailed measurements, collected over a 20-d period in September and October, included gas...

Estimating annual growth losses from drought in loblolly pine plantations

Treesearch

Ralph L. Amateis; Harold E. Burkhart; Daniel Waiswa

2013-01-01

Growth data over the past 10 years from loblolly pine (Pinus taeda L.) plantations established across the natural range of the species were linked with annual rainfall data over the same period to evaluate the impact of drought on stand growth. Regression procedures were used to determine (1) whether dominant height growth or basal area growth or...

Seasonal Dynamics in Leaf Area Index in Intensively Managed Loblolly Pine

Treesearch

Timothy B. Harrington; Jason A. Gatch; Bruce E. Borders

2002-01-01

Leaf area index (LAI; leaf area per ground area) was measured monthly or bimonthly for two years (March 1999 to February 2001) with the LAI-2000 in intensively managed plantations of loblolly pine (Pinus taeda L.) at Eatonton and Waycross GA. Since establishment of the three age classes at each site, the stands have received combinations of complete...

Growth responses of mature loblolly pine to dead wood manipulations

Treesearch

Michael D. Ulyshen; Scott Horn; James L. Hanula

2012-01-01

Large-scale manipulations of dead wood in mature Pinus taeda L. stands in the southeastern United States included a major one-time input of logs (fivefold increase in log volume) created by felling trees onsite, annual removals of all dead wood above ≥10 cm in diameter and ≥60 cm in length, and a reference in which no...

A Loblolly Pine Management Guide: When and Where to Apply Fertilizer

Treesearch

Carol G. Wells; Lee Allen

1985-01-01

Growth rates in loblolly pine (Pinus taeda L.) stands can often be increased markedly by applying phosphorus, nitrogen, or nitrogen and phosphorus fertilizers. On phosphorus-deficient Lowe Coastal Plain sites, the growth improvement from phosphorus fertilization of loblolly pine often amounts to an increase in site index (age 25) of 15 feet.Nitrogen and nitrogen plus...

Regional calibration models for predicting loblolly pine tracheid properties using near-infrared spectroscopy

Treesearch

Mohamad Nabavi; Joseph Dahlen; Laurence Schimleck; Thomas L. Eberhardt; Cristian Montes

2018-01-01

This study developed regional calibration models for the prediction of loblolly pine (Pinus taeda) tracheid properties using near-infrared (NIR) spectroscopy. A total of 1842 pith-to-bark radial strips, aged 19–31 years, were acquired from 268 trees from 109 stands across the southeastern USA. Diffuse reflectance NIR spectra were collected at 10-mm...

Site Index Curves for Direct-Seeded Loblolly and Longleaf Pines in Louisiana

Treesearch

Quang V. Cao; V. Clark Baldwin; Richard E. Lohrey

1995-01-01

Site index equations were developed for direct-seeded loblollypine (Pinus taeda L.) and longleaf pine (Pinus palustris Mill.) based on data from 148 and 75 permanent plots, respectively. These plots varied from 0.053 to 0.119 ac in size, and were established in broadcast, row, and spot seeded stands throughout Louisiana. The Bailey and Clutter (1974) model was...

Longitudial variation in wood specific gravity of planted loblolly pine in the southern United States

Treesearch

Finto Antony; Laurence R. Schimleck; Richard F. Daniels; Alexander Clark

2012-01-01

Loblolly pine (Pinus taeda L.) is the most important plantation species grown in the southern United States, having more than half of the standing pine volume. Wood from loblolly pine is a principal source of raw material for the pulp and paper industry and is desirable for the production of lumber and composite wood products. The quality of wood...

Loblolly and shortleaf pine seed viability through 21 months of field storage: Can carry-over occur between seed crops?

Treesearch

Michael D. Cain; Michael G. Shelton

1997-01-01

About two-thirds of pine stands in the southeastern United States originated from natural seedfall (USDA Forest Service 1988) and this method of regeneration continues to be impor-tant for perpetuating the species. Loblolly and shortleaf pines (Pinus taeda L. and Pinus echinatu Mill., respectively) are common associates throughout this geographic area and are the most...

Initial response of loblolly pine and competition to mid rotation fertilization and herbicide application in the gulf coastal plain

Treesearch

Hal O. Liechty; Conner Fristoe

2010-01-01

Application of N and P to mid-rotation loblolly pines (Pinus taeda L.) stands is a common silvicultural practice used to increase crop tree production in the Gulf Coastal Plain. Mid-rotation applications of herbicides or combined applications of herbicide and fertilizer are a less common practice. We applied herbicide (1.17 l imazapyr and 0.23 l...

Impacts of multiple applications of fertilizer on stream chemistry in the Ouachita Mountains

Treesearch

Hal O. Liechty; Jami Nettles; Stacy Wilson

2006-01-01

We have previously reported changes in stream chemistry following a late winter application of urea and diammonium phosphate to a loblolly pine (Pinus taeda L.) plantation located in a 176-ha subwatershed in the Ouachita Mountains. This stand was again fertilized with 437 kg/ha of urea in March of 2001. Water chemistry prior to, during, and after...

Linking growth and yield and process models to estimate impact of environmental changes on growth of loblolly pine

Treesearch

V. Clark Baldwin; Harold E. Burkhart; James A. Westfall; Kelly D. Peterson

2001-01-01

PTAEDA2 is a distance-dependent, individual tree model that simulates the growth and yield of a plantation of loblolly pine (Pinus taeda L.)on an annual basis. The MAESTRO model utilizes an array of trees in a stand to calculate and integrate the effects of biological and physical variables on the photosynthesis and respiration processes of a target...

A comparison of sample unit designs in the national inventory of the U.S.

Treesearch

B. E. Borders; G. H. Brister; N. Grahl; B. D. Shiver; C. J. Cieszewski

2000-01-01

The Forest Inventory and Analysis (FIA) program of the USDA Forest Service has adopted a new sampling unit for the national forest inventory of the U.S. We compared this new sampling unit with five other sampling units. Data from natural loblolly pine (Pinus taeda L.) stands in the Georgia piedmont show that all sample units produce reasonable...

Hardwood vigor and survival following applications of imazapyr in mid-rotation pine plantations

Treesearch

Prabudhda Dahal Dahal; Hal O. Liechty; Bryan Rupar; Conner Fristoe; Eric Heitzman

2006-01-01

Tree vigor, live crown ratios, dieback, and survival of hardwood competition were monitored for 2 years following a fall application (16 ounces per acre) of imazapyr on 4 stands of loblolly pine (Pinus taeda L.) in the Gulf Coastal Plain of Louisiana and Arkansas. Assessments during the first growing season following application indicated that 87 to...

Silviculture's impact on the historical shortleaf component of pine forests in the Upper West Gulf Coastal Plain

Treesearch

Don C. Bragg

2016-01-01

Silvicultural practices and human-induced alterations to natural disturbance regimes have contributed to a dramatic decline in shortleaf pine (Pinus echinata) across most of the Upper West Gulf Coastal Plain (UWGCP). The increased preference for faster-growing loblolly pine (Pinus taeda) in natural-origin stands, coupled with the spread of loblolly plantations and less...

Comparison of three site preparation techniques on growth of planted loblolly pine 6 years after a southern pine beetle epidemic

Treesearch

Wayne K. Clatterbuck; Michael Carr

2013-01-01

Three site preparation treatments: (1) complete removal of woody debris—drum chopped, raked, and disked; (2) drum chopping leaving woody debris; and (3) no site preparation—planting among dead standing trees were compared by evaluating the growth and survival of planted loblolly pine (Pinus taeda L.) after six growing seasons following a southern...

Continuous Cover Forestry in the United States--Experience With Southern Pines

Treesearch

James M. Guldin

2002-01-01

Continuous cover forestry (CCF) has not been common in the southern United States, but if does exist. The best record of reseurch and practice exists for mixed loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands in the Upper West Gulf Coastal Plain west of the Mississippi River. After 60 years, the Good and Poor...

Radial growth trends of loblolly pine in the Virginia Coastal Plain

Treesearch

Gregory A. Reams

1996-01-01

A number of recent studies have shown reduced individual-treerowth throughout the 1970s and early 1980s in natural loblolly pine (Pinus taeda L.) stands in the southeastern United States. This study updates radial growth trends of loblolly pine in the Virginia Coastal Plain through1989.Ring-width series were initially grouped into two age-classes (=150...

Eleventh-year response of loblolly pine and competing vegetation to woody and herbaceous plant control on a Georgia flatwoods site

Treesearch

Bruce R. Zutter; James H. Miller

1998-01-01

Through 11 growing seasons, growth of loblolly pine (Pinus taeda L.) increased after control of herbaceous, woody, or both herbaceous and woody vegetation (total control) for the first 3 years after planting on a bedded site in the Georgia coastal flatwoods. Gains in stand volume index from controlling either herbaceous or woody vegetation alone were approximately two-...

Stem Sinuosity, Tree Size, and Pest Injury of Machine-Planted Tress with and without Bent Taproots: A Comparison of Loblolly and Slash Pine

Treesearch

Jason A. Gatch; Timothy B. Harrington; Terry S. Price; M. Boyd Edwards

1999-01-01

Twenty-four maohine-planted stands each of slash (Pinus elliottii Engelm.) and loblolly pine (Pinus taeda L.) (between ages 3 to 10 years) were randomly selected in the Coastal Plain and Piedmont of Georgia, respectively. Ten points per site were located along a transect and two planted trees within a 10-m radius of each point were...

Hydraulic redistribution of soil water by roots affects whole-stand evapotranspiration and net ecosystem carbon exchange

Treesearch

J.-C. Domec; J.S. King; A. Noormets; E. Treasure; M.J. Gavazzi; G. Sun; S.G. McNulty

2010-01-01

Hydraulic redistribution (HR) of water via roots from moist to drier portions of the soil occurs in many ecosystems, potentially influencing both water use and carbon assimilation. By measuring soil water content, sap flow and eddy covariance, we investigated the temporal variability of HR in a loblolly pine (Pinus taeda) plantation during months of...

Two anomalous cardiovascular responses to active standing in essential hypertension.

PubMed

Bettencourt, M Joaquina; Pinto, Basílio Gomes; de Oliveira, E Infante; Silva-Carvalho, L

2008-05-01

In a previous work we studied, non-invasively, autonomic nervous system control of circulation in healthy subjects, observing the hemodynamic reaction to active standing. We now propose to extend this analysis to essential hypertension (EH), investigating possible autonomic dysfunction. The cardiovascular response to postural change from the supine position to active standing of 48 EH patients, of both sexes, with and without medication, was compared with that obtained for healthy subjects. We evaluated arterial systolic (SBP) and diastolic (DBP) blood pressure, stroke volume (SV), inotropic index (INOI), total vascular resistance (TVR), cardiac work (W), stroke work (SW), arterial compliance (AC) and heart rate (HR), using the entirely non-invasive BoMed NCCOM3 thoracic electrical bioimpedance monitor and sphygmomanometry. We found two patient groups characterized by different linear relationships between values of cardiovascular variables in active standing and in supine positions. Except for HR, in both groups these regression lines differed from normal. Compared to the supine position, in active standing, one group (EH-I) presented increased TVR, diminished SV, INOI, W, SW, and AC, and normal HR; the other group (EH-II) presented diminished TVR and HR and increased SV, INOI, W, SW and AC. The two patient groups could be separated on the basis of their age, but not on the basis of their systolic, diastolic and mean arterial blood pressures, gender or medication. The younger patient group (EH-I) included 28 subjects aged 24 to 69 years (50+/-10), of whom 11 were unmedicated, and the older patient group (EH-II) included 20 subjects aged 35 to 75 years (62+/-11), of whom 7 were unmedicated. Our results show a depressed response in postural change for older patients, which in the autonomic control of circulation expresses carotid baroreflex impairment, and conversely an enhanced response for younger patients, which can be caused by a maladjustment of the influence

PID Controller Design for FES Applied to Ankle Muscles in Neuroprosthesis for Standing Balance

PubMed Central

Rouhani, Hossein; Same, Michael; Masani, Kei; Li, Ya Qi; Popovic, Milos R.

2017-01-01

Closed-loop controlled functional electrical stimulation (FES) applied to the lower limb muscles can be used as a neuroprosthesis for standing balance in neurologically impaired individuals. The objective of this study was to propose a methodology for designing a proportional-integral-derivative (PID) controller for FES applied to the ankle muscles toward maintaining standing balance for several minutes and in the presence of perturbations. First, a model of the physiological control strategy for standing balance was developed. Second, the parameters of a PID controller that mimicked the physiological balance control strategy were determined to stabilize the human body when modeled as an inverted pendulum. Third, this PID controller was implemented using a custom-made Inverted Pendulum Standing Apparatus that eliminated the effect of visual and vestibular sensory information on voluntary balance control. Using this setup, the individual-specific FES controllers were tested in able-bodied individuals and compared with disrupted voluntary control conditions in four experimental paradigms: (i) quiet-standing; (ii) sudden change of targeted pendulum angle (step response); (iii) balance perturbations that simulate arm movements; and (iv) sudden change of targeted angle of a pendulum with individual-specific body-weight (step response). In paradigms (i) to (iii), a standard 39.5-kg pendulum was used, and 12 subjects were involved. In paradigm (iv) 9 subjects were involved. Across the different experimental paradigms and subjects, the FES-controlled and disrupted voluntarily-controlled pendulum angle showed root mean square errors of <1.2 and 2.3 deg, respectively. The root mean square error (all paradigms), rise time, settle time, and overshoot [paradigms (ii) and (iv)] in FES-controlled balance were significantly smaller or tended to be smaller than those observed with voluntarily-controlled balance, implying improved steady-state and transient responses of FES

Effects of rehabilitative horse riding on the Sit-to-Stand action of the adolescent with brain lesions.

PubMed

Lee, Jang Won; Han, A-Reum; Kim, Kihong

2014-02-01

The purpose of this study was to investigate the balance abilities of the adolescent girl with brain lesions by Sit-to-Stand (STS) action analysis before and after the rehabilitative horse riding of 16 week program. The subject aged 16 yr old who had the disabilities of spasticity and hemiplegia was recruited with the consent approval. The equilibrium abilities of the subject were tested by Sit-to-Stand examination with Weight Transfer Time (WTT), Mean Rising Index (MRI), Mean Weight Asymmetry (MWA), Max Trunk Flexion Velocity (MTFV), and Max Trunk Extension Velocity (MTEV). Research was designed by AB single subject study with baseline of 3 times of measurement and rehabilitative horse riding treatments. In the results, the enhancement of the subject's equilibrium ability was shown from the comparisons between baseline and treatment by the STS test that WTT was 2.37 sec faster, MRI was 6.64 N/kg higher, and MWA was 8.12% lower, and MTFV was 0.57°/sec larger than all those means of baseline. It suggested that the subject showed her enhanced balance ability while in sitting and standing after the rehabilitative horse riding treatments.

The effect of foot arch on plantar pressure distribution during standing.

PubMed

Periyasamy, R; Anand, Sneh

2013-07-01

The aim of this study was to explore how foot type affects plantar pressure distribution during standing. In this study, 32 healthy subjects voluntarily participated and the subject feet were classified as: normal feet (n = 23), flat feet (n = 14) and high arch feet (n = 27) according to arch index (AI) values obtained from foot pressure intensity image analysis. Foot pressure intensity images were acquired by a pedopowergraph system to obtain a foot pressure distribution parameter-power ratio (PR) during standing in eight different regions of the foot. Contact area and mean PR were analysed in hind foot, mid-foot and fore foot regions. One-way analysis of variance was used to determine statistical differences between groups. The contact area and mean PR value beneath the mid-foot was significantly increased in the low arch foot when compared to the normal arch foot and high arch foot (p < 0.001) in both feet. However, subjects with low-arch feet had significantly higher body mass index (BMI) compared to subjects with high-arch feet (p < 0.05) and subjects with normal arch feet (p < 0.05) in both feet. In addition, subjects with low-arch feet had significant differences in arch index (AI) value as compared to subjects with high-arch feet (p < 0.001) and subjects with normal arch feet (p < 0.05) in both feet. Mean mid-foot PR value were positively (r = 0.54) correlated with increased arch index (AI) value. A significant (p < 0.05) change was obtained in PR value beneath the mid-foot of low arch feet when compared with other groups in both feet. The findings suggest that there is an increased mid-foot PR value in the low arch foot as compared to the normal arch foot and high arch foot during standing. Therefore, individuals with low arch feet could be at high risk for mid-foot collapse and Charcot foot problems, indicating that foot type should be assessed when determining an individual's risk for foot injury.

Stand density relationships

Treesearch

John C. Tappeiner

2013-01-01

Th inning stands (managing their densities) aff ects the development of trees and understory plants as individuals, as well as stand-level characteristics like structure, microclimate, and stand growth, habitat for various species, and fuel and potential fi re severity. Th ese characteristics and the rate of changes are aff ected by thinning severity—the reduction in...

Development of a stand density index equation for slash pine stands

Treesearch

Paul F. Doruska

2002-01-01

Stand density index (SDI) is commonly used as the basis for density management guides for even-aged forest stands. Many tree species follow the same self-thinning trajectory, allowing for the use of stand density index in such guides. Slash pine (Pinus elliottii Englem.) has been shown to depart from the self-thinning trajectory exhibited by other...

Switchgrass (Panicum virgatum) Intercropping within Managed Loblolly Pine (Pinus taeda) Does Not Affect Wild Bee Communities.

PubMed

Campbell, Joshua W; Miller, Darren A; Martin, James A

2016-11-04

Intensively-managed pine ( Pinus spp.) have been shown to support diverse vertebrate communities, but their ability to support invertebrate communities, such as wild bees, has not been well-studied. Recently, researchers have examined intercropping switchgrass ( Panicum virgatum ), a native perennial, within intensively managed loblolly pine ( P. taeda ) plantations as a potential source for cellulosic biofuels. To better understand potential effects of intercropping on bee communities, we investigated visitation of bees within three replicates of four treatments of loblolly pine in Mississippi, U.S.A.: 3-4 year old pine plantations and 9-10 year old pine plantations with and without intercropped switchgrass. We used colored pan traps to capture bees during the growing seasons of 2013 and 2014. We captured 2507 bees comprised of 18 different genera during the two-year study, with Lasioglossum and Ceratina being the most common genera captured. Overall, bee abundances were dependent on plantation age and not presence of intercropping. Our data suggests that switchgrass does not negatively impact or promote bee communities within intensively-managed loblolly pine plantations.

SETs: stand evaluation tools: I. an individual-tree approach to making stand evaluations

Treesearch

Paul S. DeBald; Joseph J. Mendel

1976-01-01

The authors outline a stand-evaluation method that stresses individuality by (1) making on-the-ground projections of individual tree development; (2) summarizing stand values in terms of the individual trees in the stand and their potential development; and (3) tailoring several management possibilities to an individual stand so the owner can choose among them.

Reduction of oxidative stress by compression stockings in standing workers.

PubMed

Flore, Roberto; Gerardino, Laura; Santoliquido, Angelo; Catananti, Cesare; Pola, Paolo; Tondi, Paolo

2007-08-01

Healthy workers who stand for prolonged periods show enhanced production of reactive oxygen species (ROS) in their systemic circulation. Oxidative stress is thought to be a risk factor for chronic venous insufficiency and other systemic diseases. To evaluate the effectiveness of compression stockings in the prevention of oxidative stress at work. ROS and venous pressure of the lower limbs were measured in 55 theatre nurses who stood in the operating theatre for >6 h, 23 industrial ironers who stood for up to 5 h during their shift and 65 outpatient department nurses and 35 laundry workers who acted as controls. Subjects and controls were examined on two consecutive days before and after work and with and without compression stockings. Without compression stockings, lower limb venous pressure increased significantly after work in all subjects and controls (P < 0.001), while only operating theatre nurses showed significantly higher mean levels of ROS (P < 0.001). There was no significant difference in venous pressures and ROS levels after work in subjects or controls when wearing compression stockings. Our data suggest a preventive role of compression stockings against oxidative stress in healthy workers with a standing occupation.

Consistent definition and application of Reineke's Stand Density Index in silviculture and stand projection

Treesearch

John D. Shaw; James N. Long

2010-01-01

Reineke’s Stand Density Index (SDI) has been available to silviculturists for over 75 years, but application of this stand metric has been inconsistent. Originally described as a measurement of relative density in single-species, even-aged stands, it has since been generalized for use in uneven-aged stands and mixed-species stands. However, methods used to establish...

Vegetation composition five years after silvicultural treatments to control competition in a natural stand of loblolly-shortleaf pines

Treesearch

M.D. Cain

2000-01-01

Woody nonpine vegetation, averaging over 6,000 rootstocksiac, was controlled by chain-saw felling, chain-saw felling plus prescribed burning,orby a broadcast herbicide spray to release even-aged loblolly and shortleafpine (Pinus taeda L. and P. echinata Mill.) saplings that became established from natural seedfall on a cutover area...

The influence of environmental, soil carbon, root, and stand characteristics on soil C02 efflux in loblolly pine (Pinus taeda L.) plantations located on the South Carolina Coastal Plain

Treesearch

Christopher M. Gough; John R. Seiler

2004-01-01

While the effect of soil temperature and rnoisture on soil C02 efflux (Ec) has becn widely investigated, the relationship between Ec and soil carbon (C). root, and stand parameters has not been comprehensively examined or quantified across extensive spatial and temporal scales. Wle measured E

20. Building 202, detail of stand A, rocket test stand ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. Building 202, detail of stand A, rocket test stand in test cell. View looking southeast. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

Weight and Volume Determination for Planted Loblolly Pine in North Louisiana

Treesearch

Ray A. Newbold; V. Clark Baldwin; Gary Hill

2001-01-01

The objective of this study was to assess the variability in weight-to-volume relationships in loblolly pine (Pinus taeda L.) plantations and to determine predictability based on stand age, site quality, and/or tree size. Trees ages ranged from 11 to 40 years, with diameters to 2 1 inches and heights to 9 1 feet. Measured site indices ranged from 45...

Will crown ideotype help determine optimum varietal silviculture?

Treesearch

Timothy J. Albaugh; Thomas R. Fox; Marco A. Yanez; Rafael A. Rubilar; Barry Goldfarb

2016-01-01

Recent advances in somatic embryogenesis permit large numbers of clonal loblolly pine (Pinus taeda L.) to be produced and deployed. Clones may have greater growth (mean annual increment exceeding 30 cubic meters per hectare per year), greater stand uniformity and may be more susceptible to genotype by environment interactions when they are deployed in intensively...

The longest active thinned and pruned loblolly pine permanent plots: the last measurement

Treesearch

Denise R. General; Curtis L. VanderSchaaf; B. Zeide

2013-01-01

The longest active study of the effects of thinning and pruning on growth of loblolly pine (Pinus taeda L.) was established by Dr. James D. Burton in 1970 in a typical 12-year-old loblolly pine (plantation was 11 years old) stand planted by then the Georgia-Pacific Corporation in the southeastern corner of Arkansas. Basal area has been maintained at...

Five years of change in an old-growth pine-hardwood remnant in Ashley County, Arkansas

Treesearch

Don C. Bragg

2006-01-01

The Levi Wilcoxon Demonstration Forest near Hamburg, Arkansas is an industrially-owned remnant of old-growth pine and hardwoods. Some of the loblolly (Pinus taeda L.) and shortleaf (Pinus echinata Mill.) pine in this stand are over 200 years old, and numerous individuals exceed 90 cm in diameter and 30 m in height. A 2000 survey of a portion of this...

Soil properties and pine growth affected by site preparation after clearcutting

Treesearch

John J. Stransky; John H. Roese; K.G. Watterson

1985-01-01

A pine-hardwood sawtimber stand in southeast Texas was clearcut in September 1972. Random plots were burned, chopped, KG-bladed, or left untreated. In the spring of 1974, 1-0 loblolly pine seedlings (Pinus taeda L.) were handplanted at 8 by 10 foot spacing. Data from soil samples, taken from the 0-5 inch depth before clearcutting and 1, 3, and 5...

Standing on a declining surface reduces transient prolonged standing induced low back pain development.

PubMed

Gallagher, Kaitlin M; Callaghan, Jack P

2016-09-01

While alternating standing position on a sloped surface has proven successful at reducing low back pain during standing, the purpose of this study was to evaluate standing solely on a declining surface to isolate the influence of the postural change. Seventeen participants performed two 75-min prolonged standing occupational simulations- level ground and declining surface. Fifty-three percent of participants (9/17) were categorized as pain developers during the level ground standing condition. For these same pain developers, their average maximum pain scores were 58% lower during sloped standing. All participants showed greater hip flexion, trunk-to-thigh angle flexion, and posterior translation of the trunk center of gravity when standing on the sloped surface. These postural changes could cause the muscles crossing the hip posteriorly to increase passive stiffness and assist with stabilizing the pelvis. This study stresses the importance of hip kinematics, not just lumbar spine posture, in reducing prolonged standing induced low back pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reducing stand densities in immature and mature stands, Applegate Watershed, Southwest Oregon.

Treesearch

Marty L. Main; Michael P. Amaranthus

1996-01-01

Abstract Throughout the Applegate watershed, dense, overstocked, immature stands of mixed conifers and hardwoods and declining stands of mature conifers present significant and complex silvicultural problems. Stand stagnation is common, as is loss of large-diameter conifers from insects and wildfire. Treatments designed to maintain or encourage development of large-...

Improvement in the physiological function and standing stability based on kinect multimedia for older people

PubMed Central

Chen, Chih-Chen

2016-01-01

[Purpose] The increase in the Taiwanese older population is associated with age-related inconveniences. Finding adequate and simple physical activities to help the older people maintaining their physiological function and preventing them from falls has become an urgent social issue. [Subjects and Methods] This study aimed to design a virtual exercise training game suitable for Taiwanese older people. This system will allow for the maintenance of the physiological function and standing stability through physical exercise, while using a virtual reality game. The participants can easily exercise in a carefree, interactive environment. This study will use Kinect for Windows for physical movement detection and Unity software for virtual world development. [Results] Group A and B subjects were involved in the exercise training method of Kinect interactive multimedia for 12 weeks. The results showed that the functional reach test and the unipedal stance test improved significantly. [Conclusion] The physiological function and standing stability of the group A subjects were examined at six weeks post training. The results showed that these parameters remained constant. This proved that the proposed system provide substantial support toward the preservation of the Taiwanese older people’ physiological function and standing stability. PMID:27190480

Improvement in the physiological function and standing stability based on kinect multimedia for older people.

PubMed

Chen, Chih-Chen

2016-04-01

[Purpose] The increase in the Taiwanese older population is associated with age-related inconveniences. Finding adequate and simple physical activities to help the older people maintaining their physiological function and preventing them from falls has become an urgent social issue. [Subjects and Methods] This study aimed to design a virtual exercise training game suitable for Taiwanese older people. This system will allow for the maintenance of the physiological function and standing stability through physical exercise, while using a virtual reality game. The participants can easily exercise in a carefree, interactive environment. This study will use Kinect for Windows for physical movement detection and Unity software for virtual world development. [Results] Group A and B subjects were involved in the exercise training method of Kinect interactive multimedia for 12 weeks. The results showed that the functional reach test and the unipedal stance test improved significantly. [Conclusion] The physiological function and standing stability of the group A subjects were examined at six weeks post training. The results showed that these parameters remained constant. This proved that the proposed system provide substantial support toward the preservation of the Taiwanese older people' physiological function and standing stability.

Effect of attentional focus strategies on peak force and performance in the standing long jump.

PubMed

Wu, Will F W; Porter, Jared M; Brown, Lee E

2012-05-01

Significant benefits in standing long jump performance have been demonstrated when subjects were provided verbal instructions that promoted an external focus of attention compared with an internal focus of attention, suggesting differences in ground reaction forces. The purpose of the present study was to evaluate peak force and jump performance between internal and external focus of attention strategies. Untrained subjects were assigned to both experimental conditions in which verbal instructions were provided to promote either an external or internal focus of attention. All subjects completed a total number of 5 standing long jumps. The results of the study demonstrated that the external focus of attention condition elicited significantly greater jump distance (153.6 ± 38.6 cm) than the internal focus of attention condition (139.5 ± 46.7 cm). There were no significant differences observed between conditions in peak force (1429.8 ± 289.1 N and 1453.7 ± 299.7 N, respectively). The results add to the growing body of literature describing the training and learning benefits of an external focus of attention. Practitioners should create standardized verbal instructions using an external focus of attention to maximize standing long jump performance.

Changing stand structure and regional growth reductions in Georgia's natural pine stands

Treesearch

W.A. Bechtold; G.A. Ruark; F.T. Lloyd

1991-01-01

Forest Inventory and Analysis (FIA) data indicate reductions in the growth of naturally regenerated pines in Georgia between the two latest measurement periods (1961-1972 vs. 1972-1982). Analysis of Covariance was used to adjust stand-level basal area growth rates for differences between periods in stand age, stand density, site index, mortality, and hardwood...

Decomposition rate comparisons between frequently burned and unburned areas of uneven-aged loblolly pine stands in southeastern Arkansas

Treesearch

Miclele Renschin; Hal O. Leichty; Michael G. Shelton

2001-01-01

Although fire has been used extensively over long periods of time in loblolly pine (Pinis taeda L.) ecosystems, little is known concerning the effects of frequent fire use on nutrient cycling and decomposition. To better understand the long-term effects of fire on these processes, foliar litter decomposition rates were quantified in a study...

Aerial shows Stennis test stands

NASA Image and Video Library

2004-04-16

An aerial photo shows the B-1/B-2 Test Stand (foreground), A-2 Test Stand (middle) and A-1 Test Stand (back). The historic stands have been used to test engines used on every manned Apollo and space shuttle mission.

Alzheimer's Disease Diagnosis in Individual Subjects using Structural MR Images: Validation Studies

PubMed Central

Vemuri, Prashanthi; Gunter, Jeffrey L.; Senjem, Matthew L.; Whitwell, Jennifer L.; Kantarci, Kejal; Knopman, David S.; Boeve, Bradley F.; Petersen, Ronald C.; Jack, Clifford R.

2008-01-01

OBJECTIVE To develop and validate a tool for Alzheimer's disease (AD) diagnosis in individual subjects using support vector machine (SVM) based classification of structural MR (sMR) images. BACKGROUND Libraries of sMR scans of clinically well characterized subjects can be harnessed for the purpose of diagnosing new incoming subjects. METHODS 190 patients with probable AD were age- and gender-matched with 190 cognitively normal (CN) subjects. Three different classification models were implemented: Model I uses tissue densities obtained from sMR scans to give STructural Abnormality iNDex (STAND)-score; and Models II and III use tissue densities as well as covariates (demographics and Apolipoprotein E genotype) to give adjusted-STAND (aSTAND)-score. Data from 140 AD and 140 CN were used for training. The SVM parameter optimization and training was done by four-fold cross validation. The remaining independent sample of 50 AD and 50 CN were used to obtain a minimally biased estimate of the generalization error of the algorithm. RESULTS The CV accuracy of Model II and Model III aSTAND-scores was 88.5% and 89.3% respectively and the developed models generalized well on the independent test datasets. Anatomic patterns best differentiating the groups were consistent with the known distribution of neurofibrillary AD pathology. CONCLUSIONS This paper presents preliminary evidence that application of SVM-based classification of an individual sMR scan relative to a library of scans can provide useful information in individual subjects for diagnosis of AD. Including demographic and genetic information in the classification algorithm slightly improves diagnostic accuracy. PMID:18054253

Association of unipedal standing time and bone mineral density in community-dwelling Japanese women.

PubMed

Sakai, A; Toba, N; Takeda, M; Suzuki, M; Abe, Y; Aoyagi, K; Nakamura, T

2009-05-01

Bone mineral density (BMD) and physical performance of the lower extremities decrease with age. In community-dwelling Japanese women, unipedal standing time, timed up and go test, and age are associated with BMD while in women aged 70 years and over, unipedal standing time is associated with BMD. The aim of this study was to clarify whether unipedal standing time is significantly associated with BMD in community-dwelling women. The subjects were 90 community-dwelling Japanese women aged 54.7 years. BMD of the second metacarpal bone was measured by computed X-ray densitometry. We measured unipedal standing time as well as timed up and go test to assess physical performance of the lower extremities. Unipedal standing time decreased with increased age. Timed up and go test significantly correlated with age. Low BMD was significantly associated with old age, short unipedal standing time, and long timed up and go test. Stepwise regression analysis revealed that age, unipedal standing time, and timed up and go test were significant factors associated with BMD. In 21 participants aged 70 years and over, body weight and unipedal standing time, but not age, were significantly associated with BMD. BMD and physical performance of the lower extremities decrease with older age. Unipedal standing time, timed up and go test, and age are associated with BMD in community-dwelling Japanese women. In women aged 70 years and over, unipedal standing time is significantly associated with BMD.

A-3 Test Stand

NASA Image and Video Library

2012-06-08

A tethered Stennis Space Center employee climbs an A-3 Test Stand ladder June 8, 2012, against the backdrop of the A-2 and B-1/B-2 stands. The new A-3 Test Stand will enable simulated high-altitude testing of next-generation rocket engines.

A-3 Test Stand

NASA Image and Video Library

2012-06-08

A tethered Stennis Space Center employee climbs an A-3 Test Stand ladded June 8, 2012, against the backdrop of the A-2 and B-1/B-2 stands. The new A-3 Test Stand will enable simulated high-altitude testing of next-generation rocket engines.

SRWC bioenergy productivity and economic feasibility on marginal lands.

PubMed

Ghezehei, Solomon B; Shifflett, Shawn D; Hazel, Dennis W; Nichols, Elizabeth Guthrie

2015-09-01

Evolving bioenergy markets necessitate consideration of marginal lands for woody biomass production worldwide particularly the southeastern U.S., a prominent wood pellet exporter to Europe. Growing short rotation woody crops (SRWCs) on marginal lands minimizes concerns about using croplands for bioenergy production and reinforces sustainability of wood supply to existing and growing global biomass markets. We estimated mean annual aboveground green biomass increments (MAIs) and assessed economic feasibility of various operationally established (0.5 ha-109 ha) SRWC stands on lands used to mitigate environmental liabilities of municipal wastewater, livestock wastewater and sludge, and subsurface contamination by petroleum and pesticides. MAIs (Mg ha(-1) yr(-1)) had no consistent relationship with stand density or age. Non-irrigated Populus, Plantanus occidentalis L. and Pinus taeda L. stands produced 2.4-12.4 Mg ha(-1) yr(-1). Older, irrigated Taxodium distchum L., Fraxinus pennsylvanica L., and coppiced P. occidentalis stands had higher MAIs (10.6-21.3 Mg ha(-1) yr(-1)) than irrigated Liquidambar styraciflua L. and non-coppiced, irrigated P. occidentalis (8-18 Mg ha(-1) yr(-1)). Natural hardwood MAIs at 20-60 years were less than hardwood and P. taeda productivities at 5-20 years. Unlike weed control, irrigation and coppicing improved managed hardwood productivity. Rotation length affected economic outcomes although the returns were poor due to high establishment and maintenance costs, low productivities and low current stumpage values, which are expected to quickly change with development of robust global markets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Natural mycorrhizal colonization of pines on reclaimed surface mines in Virginia. [Pinus strobus; Pinus taeda; Pinus virginiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoenholtz, S.H.; Burger, J.A.; Torbert, J.L.

The effects of spoil type, slow-release fertilization, and weed control using glyphosate on the degree of ectomycorrhizal colonization of container-grown white (Pinus strobus L.), loblolly (P. taeda L.), and Virginia (P. virginiana Mill.) pines were studied on two strip mined sites (sandstone vs. siltstone overburden material) in southwestern Virginia. Although some seedlings were successfully colonized at both sites, the number of seedlings colonized and the proportion of short-root colonization per seedling were consistently higher on the sandstone spoil. On both sites, loblolly and Virginia pines had more ectomycorrhizal formation than white pine. Foliar P levels of all three species onmore » the sandstone spoil and of loblolly pine on the siltstone spoil were significantly correlated with ectomycorrhizal development. The degree of ectomycorrhizal formation for any of the species on either spoil was not decreased by slow-release fertilization or glyphosate applications. These results indicate that natural mycorrhizal colonization is compatible with these cultural treatments, and that colonization from indigenous fungal species may be adequate, eliminating the need for artificial inoculation.« less

Direct measurement of the intrinsic ankle stiffness during standing.

PubMed

Vlutters, M; Boonstra, T A; Schouten, A C; van der Kooij, H

2015-05-01

Ankle stiffness contributes to standing balance, counteracting the destabilizing effect of gravity. The ankle stiffness together with the compliance between the foot and the support surface make up the ankle-foot stiffness, which is relevant to quiet standing. The contribution of the intrinsic ankle-foot stiffness to balance, and the ankle-foot stiffness amplitude dependency remain a topic of debate in the literature. We therefore developed an experimental protocol to directly measure the bilateral intrinsic ankle-foot stiffness during standing balance, and determine its amplitude dependency. By applying fast (40 ms) ramp-and-hold support surface rotations (0.005-0.08 rad) during standing, reflexive contributions could be excluded, and the amplitude dependency of the intrinsic ankle-foot stiffness was investigated. Results showed that reflexive activity could not have biased the torque used for estimating the intrinsic stiffness. Furthermore, subjects required less recovery action to restore balance after bilateral rotations in opposite directions compared to rotations in the same direction. The intrinsic ankle-foot stiffness appears insufficient to ensure balance, ranging from 0.93±0.09 to 0.44±0.06 (normalized to critical stiffness 'mgh'). This implies that changes in muscle activation are required to maintain balance. The non-linear stiffness decrease with increasing rotation amplitude supports the previous published research. With the proposed method reflexive effects can be ruled out from the measured torque without any model assumptions, allowing direct estimation of intrinsic stiffness during standing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating the Community Land Model in a pine stand with shading manipulations and 13CO2 labeling

NASA Astrophysics Data System (ADS)

Mao, J.; Ricciuto, D. M.; Thornton, P. E.; Warren, J. M.; King, A. W.; Shi, X.; Iversen, C. M.; Norby, R. J.

2016-02-01

Carbon allocation and flow through ecosystems regulates land surface-atmosphere CO2 exchange and thus is a key, albeit uncertain, component of mechanistic models. The Partitioning in Trees and Soil (PiTS) experiment-model project tracked carbon allocation through a young Pinus taeda stand following pulse labeling with 13CO2 and two levels of shading. The field component of this project provided process-oriented data that were used to evaluate terrestrial biosphere model simulations of rapid shifts in carbon allocation and hydrological dynamics under varying environmental conditions. Here we tested the performance of the Community Land Model version 4 (CLM4) in capturing short-term carbon and water dynamics in relation to manipulative shading treatments and the timing and magnitude of carbon fluxes through various compartments of the ecosystem. When calibrated with pretreatment observations, CLM4 was capable of closely simulating stand-level biomass, transpiration, leaf-level photosynthesis, and pre-labeling 13C values. Over the 3-week treatment period, CLM4 generally reproduced the impacts of shading on soil moisture changes, relative change in stem carbon, and soil CO2 efflux rate. Transpiration under moderate shading was also simulated well by the model, but even with optimization we were not able to simulate the high levels of transpiration observed in the heavy shading treatment, suggesting that the Ball-Berry conductance model is inadequate for these conditions. The calibrated version of CLM4 gave reasonable estimates of label concentration in phloem and in soil surface CO2 after 3 weeks of shade treatment, but it lacks the mechanisms needed to track the labeling pulse through plant tissues on shorter timescales. We developed a conceptual model for photosynthate transport based on the experimental observations, and we discussed conditions under which the hypothesized mechanisms could have an important influence on model behavior in larger-scale applications

Development of prolonged standing strain index to quantify risk levels of standing jobs.

PubMed

Halim, Isa; Omar, Abdul Rahman

2012-01-01

Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.

Young, Healthy Subjects Can Reduce the Activity of Calf Muscles When Provided with EMG Biofeedback in Upright Stance

PubMed Central

Vieira, Taian M.; Baudry, Stéphane; Botter, Alberto

2016-01-01

Recent evidence suggests the minimization of muscular effort rather than of the size of bodily sway may be the primary, nervous system goal when regulating the human, standing posture. Different programs have been proposed for balance training; none however has been focused on the activation of postural muscles during standing. In this study we investigated the possibility of minimizing the activation of the calf muscles during standing through biofeedback. By providing subjects with an audio signal that varied in amplitude and frequency with the amplitude of surface electromyograms (EMG) recorded from different regions of the gastrocnemius and soleus muscles, we expected them to be able to minimize the level of muscle activation during standing without increasing the excursion of the center of pressure (CoP). CoP data and surface EMG from gastrocnemii, soleus and tibialis anterior muscles were obtained from 10 healthy participants while standing at ease and while standing with EMG biofeedback. Four sensitivities were used to test subjects' responsiveness to the EMG biofeedback. Compared with standing at ease, the two most sensitive feedback conditions induced a decrease in plantar flexor activity (~15%; P < 0.05) and an increase in tibialis anterior EMG (~10%; P < 0.05). Furthermore, CoP mean position significantly shifted backward (~30 mm). In contrast, the use of less sensitive EMG biofeedback resulted in a significant decrease in EMG activity of ankle plantar flexors with a marginal increase in TA activity compared with standing at ease. These changes were not accompanied by greater CoP displacements or significant changes in mean CoP position. Key results revealed subjects were able to keep standing stability while reducing the activity of gastrocnemius and soleus without loading their tibialis anterior muscle when standing with EMG biofeedback. These results may therefore posit the basis for the development of training protocols aimed at assisting subjects in

The effect of pile size on moisture content of loblolly pine while field drying

Treesearch

John Klepac; Dana Mitchell; Jason and Thompson

2014-01-01

A 14-year old loblolly pine (Pinus taeda) plantation approximately 5 acres in size was cut during August 2013 with a tracked feller-buncher. A grapple skidder transported trees from one-half of the tract to a landing where they were piled whole-tree. Remaining trees were left whole-tree in skidder bundles (small piles) in the stand. All trees were left on-site and...

Recovery of planted loblolly pine 5 years after severe ice storms in Arkansas

Treesearch

Don C. Bragg; Michael G. Shelton

2010-01-01

Following a severe ice storm, one of a landowner’s first considerations regarding the future of their damaged stands should be on the recovery potential of injured crop trees. The ice storms that struck Arkansas in December 2000 provided an opportunity to monitor 410 injured loblolly pines (Pinus taeda L.), representing a wide range of damage in 18 –20-year-old...

49 CFR 40.21 - May an employer stand down an employee before the MRO has completed the verification process?

Code of Federal Regulations, 2010 CFR

2010-10-01

... which DOT agencies regulate your employees. (2) Your proposed written company policy concerning stand... temporary removal from performance of safety-sensitive functions becomes available, directly or indirectly... a covered employee will be subject to stand-down only with respect to the actual performance of...

Managing uneven-aged stands

Treesearch

Jay R. Law; Craig G. Lorimer

1989-01-01

Maintaining uneven-aged stands involves cutting trees from a range of diameter classes in such a way that the residual stand has a balanced, steeply descending diameter distribution curve (fig. 1). The objective is to distribute trees by diameter classes so that over time the stand contains trees of different ages and sizes.

Up, Up Up in 60 Seconds- Watch Rocket Test Stand Soar to 221-Feet Tall

NASA Image and Video Library

2017-01-09

In this 60-second time-lapse video, watch structural Test Stand 4693 at NASA's Marshall Space Flight Center rise 221 feet, from the start of construction in May 2014 to its end in December 2016. Test Stand 4693 will subject the 537,000-gallon liquid hydrogen tank of the Space Launch System's massive core stage to the same stresses and pressures it must endure at launch and in flight.

Normative values for the spine shape parameters using 3D standing analysis from a database of 268 asymptomatic Caucasian and Japanese subjects.

PubMed

Le Huec, Jean Charles; Hasegawa, Kazuhiro

2016-11-01

Sagittal balance analysis has gained importance and the measure of the radiographic spinopelvic parameters is now a routine part of many interventions of spine surgery. Indeed, surgical correction of lumbar lordosis must be proportional to the pelvic incidence (PI). The compensatory mechanisms [pelvic retroversion with increased pelvic tilt (PT) and decreased thoracic kyphosis] spontaneously reverse after successful surgery. This study is the first to provide 3D standing spinopelvic reference values from a large database of Caucasian (n = 137) and Japanese (n = 131) asymptomatic subjects. The key spinopelvic parameters [e.g., PI, PT, sacral slope (SS)] were comparable in Japanese and Caucasian populations. Three equations, namely lumbar lordosis based on PI, PT based on PI and SS based on PI, were calculated after linear regression modeling and were comparable in both populations: lumbar lordosis (L1-S1) = 0.54*PI + 27.6, PT = 0.44*PI - 11.4 and SS = 0.54*PI + 11.90. We showed that the key spinopelvic parameters obtained from a large database of healthy subjects were comparable for Causasian and Japanese populations. The normative values provided in this study and the equations obtained after linear regression modeling could help to estimate pre-operatively the lumbar lordosis restoration and could be also used as guidelines for spinopelvic sagittal balance.

Treating mature stands for wildlife

Treesearch

William H. Healy; Gary F. Houf

1989-01-01

Stands older than 60 years or that are medium to large sawtimber size generally provide good wildlife habitat. Mature trees usually produce abundant mast and provide den sites (see fig. 1 in Note 9.04 Treating Immature Stands). The undergrowth in these stands produces moderate amounts of browse and herbage. Mature stands also provide opportunities for management...

Design and characterization of a torque-controllable actuator for knee assistance during sit-to-stand.

PubMed

Shepherd, Max K; Rouse, Elliott J

2016-08-01

Individuals with post-stroke hemiparesis often have difficulty standing out of a chair. One way to potentially improve sit-to-stand is to provide knee extension assistance using a powered knee exoskeleton. An exoskeleton providing unilateral, partial assistance during sit-to-stand would need to be torque-controllable. There are no knee exoskeletons on the market suitable for conducting experiments assisting stroke patients with sit-to-stand, so to enable such experiments a research device was developed. The purpose of this report is to present the design of a novel knee exoskeleton actuator that uses a fiberglass leaf spring in series to improve torque-controllability, and present a characterization of the actuator performance. The actuator is capable of the required torque and speed for sit-to-stand, has high bandwidth (25 Hz), low output impedance at low frequencies (<;0.5 Nm), and excellent torque tracking. An orthotic brace built upon this actuator will enable an in-depth study on the biomechanical effects of providing stroke subjects with knee extension assistance during sit-to-stand.

Reineke’s stand density index: a quantitative and non-unitless measure of stand density

Treesearch

Curtis L. VanderSchaaf

2013-01-01

When used as a measure of relative density, Reineke’s stand density index (SDI) can be made unitless by relating the current SDI to a standard density but when used as a quantitative measure of stand density SDI is not unitless. Reineke’s SDI relates the current stand density to an equivalent number of trees per unit area in a stand with a quadratic mean diameter (Dq)...

Effect of In-Flight Exercise and Extravehicular Activity on Postflight Stand Tests

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Moore, Alan D., Jr.; Fritsch-Yelle, Janice; Greenisen, Michael; Schneider, Suzanne M.; Foster, Philip P.

2000-01-01

The purpose of this study was to determine whether exercise performed by Space Shuttle crewmembers during short-duration spaceflights (9-16 days) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 hr of landing. Thirty crewmembers performed self-selected in-flight exercise and maintained exercise logs to monitor their exercise intensity and duration. A 10min stand test, preceded by at least 6 min of quiet supine rest, was completed 10- 15 d before launch (PRE) and within four hours of landing (POST). Based upon their in-flight exercise records, subjects were grouped as either high (HIex: = 3x/week, HR = 70% ,HRMax, = 20 min/session, n = 11), medium (MEDex: = 3x/week, HR = 70% HRmax, = 20 min/session, n = 10), or low (LOex: = 3x/week, HR and duration variable, n = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, or analysis of variance, P < 0.05). There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared to PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36+/-5 bpm) compared to HIex or MEDex groups (25+/-1bpm; 22+/-2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after spaceflight in the MEDex and HIex groups, but was significantly less in the LOex group (PRE: -9+/- 3, POST: -19+/- 4 mmHg). Thus, moderate to high levels of in-flight exercise attenuated HR and PP responses to standing after spaceflight compared.

Stand size, stand distribution, and rotation lengths for forest wildlife

Treesearch

Steven E. Backs; Russel R. Titus

1989-01-01

The key to managing forest wildlife is providing diverse habitats. Stand size, stand distribution, and rotation length determine how diverse habitats will be. Since the tenure of private forest owners is generally shorter than prescribed rotations, rotation recommendations serve more as guides to the amount and intensity of cutting needed to maintain desired habitat....

Effects of bilateral swing-away grab bars on the biomechanics of stand-to-sit and sit-to-stand toilet transfers.

PubMed

Lee, Su Jin; Mehta-Desai, Ricky; Oh, Kyunggeune; Sanford, Jon; Prilutsky, Boris I

2018-03-09

Kinetic characteristics of transfers to and from a toilet performed using bilateral grab bars are not fully quantified to inform grab bar design and configuration. The purpose of this study was to (1) determine effects of bilateral swing-away grab bars on peaks of ankle, knee and hip joint moments during grab bar assisted stand-to-sit and sit-to-stand transfers; and (2) determine effects of three different heights and widths of swing-away grab bars on the same kinetic characteristics. Healthy subjects (N = 11, age 25-58 years) performed stand-to-sit and sit-to-stand transfers with and without grab bars. In transfers with grab bars, 9 grab bar configurations were tested by varying their height from the floor (0.787 m, 0.813 m, 0.838 m; 31″-33″) and width, the distance of each grab bar from the toilet's centerline (0.330 m, 0.356 m, 0.381 m; 13″-15″). Motion capture, force plate and inverse dynamics analysis were used to determine lower limb joint moments. The use of bilateral grab bars generally reduced the peak magnitude of extension moments at lower limb joints during stand-to-sit and sit-to-stand transfers (p < .05), except the ankle joint moments during stand-to-sit transfers. Relatively few differences in peak joint moments were found between studied grab bar widths or heights. The obtained results suggest that the studied ranges of grab bar configurations reduce moment demands on the leg joints and thus decrease difficulty and required lower limb muscle effort to perform the transfers. Implications for Rehabilitation Maximizing the benefits of assistive technology in the built environment requires a careful assessment of their spatial and configurational dimensions, especially in respect to the needs and abilities of the intended users. Examining the kinetic characteristics of transfers to and from a toilet using the swing-away grab bars is useful for informing grab bar design and configuration recommendations for assisted living

40 CFR 201.16 - Standard for locomotive load cell test stands.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Standard for locomotive load cell test... Interstate Rail Carrier Operations Standards § 201.16 Standard for locomotive load cell test stands. (a) Effective January 15, 1984, no carrier subject to this reguation shall operate locomotive load cell test...

40 CFR 201.16 - Standard for locomotive load cell test stands.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Standard for locomotive load cell test... Interstate Rail Carrier Operations Standards § 201.16 Standard for locomotive load cell test stands. (a) Effective January 15, 1984, no carrier subject to this reguation shall operate locomotive load cell test...

40 CFR 201.16 - Standard for locomotive load cell test stands.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Standard for locomotive load cell test... Interstate Rail Carrier Operations Standards § 201.16 Standard for locomotive load cell test stands. (a) Effective January 15, 1984, no carrier subject to this reguation shall operate locomotive load cell test...

40 CFR 201.16 - Standard for locomotive load cell test stands.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Standard for locomotive load cell test... Interstate Rail Carrier Operations Standards § 201.16 Standard for locomotive load cell test stands. (a) Effective January 15, 1984, no carrier subject to this reguation shall operate locomotive load cell test...

40 CFR 201.16 - Standard for locomotive load cell test stands.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Standard for locomotive load cell test... Interstate Rail Carrier Operations Standards § 201.16 Standard for locomotive load cell test stands. (a) Effective January 15, 1984, no carrier subject to this reguation shall operate locomotive load cell test...

Physico-Chemical Properties and Biodegradability of Genetically Modified Populus trichocarpa and Pinus taeda

NASA Astrophysics Data System (ADS)

Edmunds, Charles Warren

Increasing concerns over greenhouse gas emissions and the finite supply of fossil fuels lead to the goal of utilizing lignocellulosic feedstocks for biofuels, platform chemicals, and biocomposites. Lignin is responsible for the recalcitrance of lignocellulosic biomass and is a major barrier to its deconstruction. Great progress has been made in mapping and modifying the lignin biosynthetic pathway. However, the link between the genetic modification, resulting chemical and physical properties of the wood, and how these properties influence the thermomechanical and recalcitrance to biological and chemical degradation needs further investigation. In this dissertation, the study of modified Populus trichocarpa and Pinus taeda were utilized to accomplish this goal. Thermo-mechanical properties of genetically modified P. trichocarpa with altered lignin content and/or lignin structure were measured with a series of tools including; dynamic mechanical analysis, nuclear magnetic resonance, and wet chemistry techniques. Results demonstrated lignin content and lignin structure likely influence the glass transition temperature (Tg), and that decreased lignin content and the corresponding higher proportion of cell wall carbohydrates may contribute to increased molecular mobility in the wood polymer structure. The effect of lignin biosynthetic pathway modification on biological degradation of these transgenic wood specimens was of interest. However, experimental methods for fungal treatment on small young greenhouse-grown wood specimens are not well established. Therefore, a project was undertaken to develop a method for fungal inoculation and incubation for these unique specimens. Several parameters were tested, and a fungal treatment method was identified with sufficient weight loss after decay and significant reduction in variation of weight loss between replicates compared to previous experiments by direct inoculation of wood with liquid malt extract fungal culture

The interactive impact of forest site and stand attributes and logging technology on stand management

Treesearch

C.B. LeDoux; J.E. Baumgras

1991-01-01

The impact of selected site and stand attributes on stand management is demonstrated using actual forest model plot data and a complete systems simulation model called MANAGE. The influence of terrain on the type of logging technology required to log a stand and the resulting impact on stand management is also illustrated. The results can be used by managers and...

A-3 Test Stand construction

NASA Image and Video Library

2010-10-01

An 80,000-gallon liquid hydrogen tank is placed at the A-3 Test Stand construction site on Sept. 24, 2010. The tank will provide propellant for tests of next-generation rocket engines at the stand. It will be placed upright on top of the stand, helping to increase the overall height to 300 feet. Once completed, the A-3 Test Stand will enable operators to test rocket engines at simulated altitudes of up to 100,000 feet. The A-3 stand is the first large rocket engine test structure to be built at Stennis Space Center since the 1960s.

A-3 Test Stand construction

NASA Image and Video Library

2010-09-24

A 35,000-gallon liquid oxygen tank is placed at the A-3 Test Stand construction site on Sept. 24, 2010. The tank will provide propellant for tests of next-generation rocket engines at the stand. It will be placed upright on top of the stand, helping to increase the overall height to 300 feet. Once completed, the A-3 Test Stand will enable operators to test rocket engines at simulated altitudes of up to 100,000 feet. The A-3 stand is the first large rocket engine test structure to be built at Stennis Space Center since the 1960s.

The Plantation Conversion Demonstration at the Crossett Experimental Forest--Implications For Converting Stands From Even-Aged to Uneven-Aged Structure

Treesearch

James M. Guldin; Robert M. Farrar

2002-01-01

In the absence of replicated studies, we used a case study demonstration to illustrate converting a 26-year-old even-aged loblolly pine (Pinus taeda L.) plantation to uneven-aged structure. Unreplicated treatments included maintaining even-aged structure through low thinning (thinning from below) to a residual basal area of 80 square feet per acre,...

IDEEA activity monitor: validity of activity recognition for lying, reclining, sitting and standing.

PubMed

Jiang, Yuyu; Larson, Janet L

2013-03-01

Recent evidence demonstrates the independent negative effects of sedentary behavior on health, but there are few objective measures of sedentary behavior. Most instruments measure physical activity and are not validated as measures of sedentary behavior. The purpose of this study was to evaluate the validity of the IDEEA system's measures of sedentary and low-intensity physical activities: lying, reclining, sitting and standing. Thirty subjects, 14 men and 16 women, aged 23 to 77 years, body mass index (BMI) between 18 to 34 kg/m(2), participated in the study. IDEEA measures were compared to direct observation for 27 activities: 10 lying in bed, 3 lying on a sofa, 1 reclining in a lawn chair, 10 sitting and 3 standing. Two measures are reported, the percentage of activities accurately identified and the percentage of monitored time that was accurately labeled by the IDEEA system for all subjects. A total of 91.6% of all observed activities were accurately identified and 92.4% of the total monitored time was accurately labeled. The IDEEA system did not accurately differentiate between lying and reclining so the two activities were combined for calculating accuracy. Using this approach the IDEEA system accurately identified 96% of sitting activities for a total of 97% of the monitored sitting time, 99% and 99% for standing, 87% and 88% for lying in bed, 87% and 88% for lying on the sofa, and 83% and 83% for reclining on a lawn chair. We conclude that the IDEEA system accurately recognizes sitting and standing positions, but it is less accurate in identifying lying and reclining positions. We recommend combining the lying and reclining activities to improve accuracy. The IDEEA system enables researchers to monitor lying, reclining, sitting and standing with a reasonable level of accuracy and has the potential to advance the science of sedentary behaviors and low-intensity physical activities.

Support surface related changes in feedforward and feedback control of standing posture

PubMed Central

Mohapatra, Sambit; Kukkar, Komal K.; Aruin, Alexander S.

2013-01-01

The aim of the study was to investigate the effect of different support surfaces on feedforward and feedback components of postural control. Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing on a rigid platform, foam, and wobble board with eyes open or closed. Electrical activity of nine trunk and leg muscles and displacements of the center of pressure were recorded and analyzed during the time frames typical of feedforward and feedback postural adjustments. Feedforward control of posture was characterized by earlier activation of anterior muscles when the subjects stood on foam compared to a wobble board or a firm surface. In addition, the magnitude of feedforward muscle activity was the largest when the foam was used. During the feedback control, anterior muscles were activated prior to posterior muscles irrespective of the nature of surface. Moreover, the largest muscle activity was seen when the supporting surface was foam. Maximum CoP displacement occurred when subjects were standing on a rigid surface. Altering support surface affects both feedforward and feedback components of postural control. This information should be taken into consideration in planning rehabilitation interventions geared towards improvement of balance. PMID:24268589

Projecting a Stand Table Through Time

Treesearch

Quang V. Cao; V. Clark Baldwin

1999-01-01

Stand tables provide number of trees per acre for each diameter class. This paper presents a general technique to predict a future stand table, based on the current stand table and future stand summary statistics such as trees and basal area per acre, and average diameter. The stand projection technique involves (a) predicting surviving trees for each class, and (b)...

Characterization and enzymatic hydrolysis of wood from transgenic Pinus taeda engineered with syringyl lignin or reduced lignin content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edmunds, Charles W.; Peralta, Perry; Kelley, Stephen S.

Softwood is an abundant resource; however, currently its utilization for bioconversion to obtain platform sugars is limited. Pinus taeda trees which were genetically modified to either produce S lignin or to decrease lignin content were characterized with a suite of analytic techniques. Syringyl lignin was visualized in the secondary xylem of one genetic line with Maule staining. Solid-state nuclear magnetic resonance identified the S lignin units were coupled into the lignin through β-O-4 linkages, and thioacidolysis measured approximately 13% S lignin content in the same sample. Reductions of the lignin of as much as 33% were observed in the transgenics.more » To better understand how these modifications affect bioconversion, their amenability to hot water and dilute acid pretreatments and enzymatic hydrolysis was evaluated. Lignin reductions resulted in 1.9-3.2-fold increases in glucose release compared to the control. However, no apparent benefit was observed by S lignin incorporation at the concentrations reported in this study. Finally, these results highlight the potential for softwood cell wall properties to be improved for bioenergy/biochemical applications.« less

Characterization and enzymatic hydrolysis of wood from transgenic Pinus taeda engineered with syringyl lignin or reduced lignin content

DOE PAGES

Edmunds, Charles W.; Peralta, Perry; Kelley, Stephen S.; ...

2017-02-22

Softwood is an abundant resource; however, currently its utilization for bioconversion to obtain platform sugars is limited. Pinus taeda trees which were genetically modified to either produce S lignin or to decrease lignin content were characterized with a suite of analytic techniques. Syringyl lignin was visualized in the secondary xylem of one genetic line with Maule staining. Solid-state nuclear magnetic resonance identified the S lignin units were coupled into the lignin through β-O-4 linkages, and thioacidolysis measured approximately 13% S lignin content in the same sample. Reductions of the lignin of as much as 33% were observed in the transgenics.more » To better understand how these modifications affect bioconversion, their amenability to hot water and dilute acid pretreatments and enzymatic hydrolysis was evaluated. Lignin reductions resulted in 1.9-3.2-fold increases in glucose release compared to the control. However, no apparent benefit was observed by S lignin incorporation at the concentrations reported in this study. Finally, these results highlight the potential for softwood cell wall properties to be improved for bioenergy/biochemical applications.« less

Effects of Stand and Step Training with Epidural Stimulation on Motor Function for Standing in Chronic Complete Paraplegics

PubMed Central

Rejc, Enrico; Angeli, Claudia A.; Bryant, Nicole

2017-01-01

Abstract Individuals affected by motor complete spinal cord injury are unable to stand, walk, or move their lower limbs voluntarily; this diagnosis normally implies severe limitations for functional recovery. We have recently shown that the appropriate selection of epidural stimulation parameters was critical to promoting full-body, weight-bearing standing with independent knee extension in four individuals with chronic clinically complete paralysis. In the current study, we examined the effects of stand training and subsequent step training with epidural stimulation on motor function for standing in the same four individuals. After stand training, the ability to stand improved to different extents in the four participants. Step training performed afterwards substantially impaired standing ability in three of the four individuals. Improved standing ability generally coincided with continuous electromyography (EMG) patterns with constant levels of ground reaction forces. Conversely, poorer standing ability was associated with more variable EMG patterns that alternated EMG bursts and longer periods of negligible activity in most of the muscles. Stand and step training also differentially affected the evoked potentials amplitude modulation induced by sitting-to-standing transition. Finally, stand and step training with epidural stimulation were not sufficient to improve motor function for standing without stimulation. These findings show that the spinal circuitry of motor complete paraplegics can generate motor patterns effective for standing in response to task-specific training with optimized stimulation parameters. Conversely, step training can lead to neural adaptations resulting in impaired motor function for standing. PMID:27566051

Plume dispersion in four pine thinning scenarios: development of a simple pheromone dispersion model

Treesearch

Holly Peterson; Harold Thistle; Brian Lamb; Gene Allwine; Steve Edburg; Brian Strom

2010-01-01

A unique field campaign was conducted in 2004 to examine how changes in stand density may affect dispersion of insect pheromones in forest canopies. Over a l4-day period, 126 tracer tests were performed, and conditions ranged from an unthinned loblolly pine (Pinus taeda) canopy through a series of thinning scenarios with basal areas of32.l, 23.0, and 16.1 m2ha-l.ln...

Genetic and Spacing Effects on Loblolly Pine Plantation Development Through Age 17

Treesearch

Samuel B. Land; Scott D. Roberts; Howard W. Duzan

2004-01-01

Eight North Carolina families and a Mississippi-Alabama commercial check of loblolly pine (Pinus taeda L.) were planted at three spacings (5x5, 8x8, and 10x10 feet) in east Mississippi. Results for ages 5, 9, 13, and 17 years indicated that spacing effects occurred by age 5 for d.b.h. and height and by age 9 for survival, stand volume, and periodic...

Variable Cadence Walking and Ground Adaptive Standing with a Powered Ankle Prosthesis

PubMed Central

Shultz, Amanda H.; Lawson, Brian E.; Goldfarb, Michael

2015-01-01

Abstract This paper describes a control approach that provides walking and standing functionality for a powered ankle prosthesis, and demonstrates the efficacy of the approach in experiments in which a unilateral transtibial amputee subject walks with the prosthesis at variable cadences, and stands on various slopes. Both controllers incorporate a finite-state structure that emulates healthy ankle joint behavior via a series of piecewise passive impedance functions. The walking controller incorporates an algorithm to modify impedance parameters based on estimated cadence, while the standing controller incorporates an algorithm to modulate the ankle equilibrium angle in order to adapt to the ground slope and user posture, and the supervisory controller selects between the walking and standing controllers. The system is shown to reproduce several essential biomechanical features of the healthy joint during walking, particularly relative to a passive prosthesis, and is shown to adapt to variable cadences. The system is also shown to adapt to slopes over a range of ± 15 deg and to provide support to the user in a manner that is biomimetic, as validated by quasi-static stiffness measurements recorded by the prosthesis. Data from standing trials indicate that the user places more weight on the powered prosthesis than on his passive prosthesis when standing on sloped surfaces, particularly at angles of 10 deg or greater. The authors also demonstrated that the prosthesis typically began providing support within 1 s of initial contact with the ground. Further, the supervisory controller was shown to be effective in switching between walking and standing, as well as in determining ground slope just prior to the transition from the standing controller to the walking controller, where the estimated ground slope was within 1.25 deg of the actual ground slope for all trials. PMID:25955789

Learning to Stand: The Acceptability and Feasibility of Introducing Standing Desks into College Classrooms

PubMed Central

Benzo, Roberto M.; Gremaud, Allene L.; Jerome, Matthew; Carr, Lucas J.

2016-01-01

Prolonged sedentary behavior is an independent risk factor for multiple negative health outcomes. Evidence supports introducing standing desks into K-12 classrooms and work settings to reduce sitting time, but no studies have been conducted in the college classroom environment. The present study explored the acceptability and feasibility of introducing standing desks in college classrooms. A total of 993 students and 149 instructors completed a single online needs assessment survey. This cross-sectional study was conducted during the fall semester of 2015 at a large Midwestern University. The large majority of students (95%) reported they would prefer the option to stand in class. Most students (82.7%) reported they currently sit during their entire class time. Most students (76.6%) and instructors (86.6%) reported being in favor of introducing standing desks into college classrooms. More than half of students and instructors predicted having access to standing desks in class would improve student’s “physical health”, “attention”, and “restlessness”. Collectively, these findings support the acceptability of introducing standing desks in college classrooms. Future research is needed to test the feasibility, cost-effectiveness and efficacy of introducing standing desks in college classrooms. Such studies would be useful for informing institutional policies regarding classroom designs. PMID:27537901

A-3 Test Stand work

NASA Image and Video Library

2011-07-29

Work continues on the A-3 Test Stand at Stennis Space Center. The new stand will allow operators to test next-generation rocket engines at simulated altitudes up to 100,000 feet. The test stand is scheduled for completion and activation in 2013.

Determining maximum stand density index in mixed species stands for strategic-scale stocking assessments

Treesearch

Chris W. Woodall; Patrick D. Miles; John S. Vissage

2005-01-01

Stand density index (SDI), although developed for use in even-aged monocultures, has been used for assessing stand density in large-scale forest inventories containing diverse tree species and size distributions. To improve application of SDI in unevenaged, mixed species stands present in large-scale forest inventories, trends in maximum SDI across diameter classes...

Inertial Sensor Based Analysis of Lie-to-Stand Transfers in Younger and Older Adults

PubMed Central

Schwickert, Lars; Boos, Ronald; Klenk, Jochen; Bourke, Alan; Becker, Clemens; Zijlstra, Wiebren

2016-01-01

Many older adults lack the capacity to stand up again after a fall. Therefore, to analyse falls it is relevant to understand recovery patterns, including successful and failed attempts to get up from the floor in general. This study analysed different kinematic features of standing up from the floor. We used inertial sensors to describe the kinematics of lie-to-stand transfer patterns of younger and healthy older adults. Fourteen younger (20–50 years of age, 50% men) and 10 healthy older community dwellers (≥60 years; 50% men) conducted four lie-to-stand transfers from different initial lying postures. The analysed temporal, kinematic, and elliptic fitting complexity measures of transfer performance were significantly different between younger and older subjects (i.e., transfer duration, angular velocity (RMS), maximum vertical acceleration, maximum vertical velocity, smoothness, fluency, ellipse width, angle between ellipses). These results show the feasibility and potential of analysing kinematic features to describe the lie-to-stand transfer performance, to help design interventions and detection approaches to prevent long lies after falls. It is possible to describe age-related differences in lie-to-stand transfer performance using inertial sensors. The kinematic analysis remains to be tested on patterns after real-world falls. PMID:27529249

A-1 Test Stand work

NASA Technical Reports Server (NTRS)

2010-01-01

Employees at NASA's John C. Stennis Space Center work to maneuver a structural steam beam into place on the A-1 Test Stand on Jan. 13. The beam was one of several needed to form the thrust takeout structure that will support a new thrust measurement system being installed on the stand for future rocket engine testing. Once lifted onto the stand, the beams had to be hoisted into place through the center of the test stand, with only two inches of clearance on each side. The new thrust measurement system represents a state-of-the-art upgrade from the equipment installed more than 40 years ago when the test stand was first constructed.

Saw gin stands

USDA-ARS?s Scientific Manuscript database

The saw gin stand is the heart of the saw ginning system. Almost from the initial filing of patents for the spiked tooth gin and the saw gin in 1794 and 1796 by Whitney and then Holmes respectively (Hughs and Holt, 2015), the saw gin stand has predominated over early roller-type gins in the U.S. co...

PPT Thrust Stand

NASA Technical Reports Server (NTRS)

Haag, Thomas W.

1995-01-01

A torsional-type thrust stand has been designed and built to test Pulsed Plasma Thrusters (PPT's) in both single shot and repetitive operating modes. Using this stand, momentum per pulse was determined strictly as a function of thrust stand deflection, spring constant, and natural frequency. No empirical corrections were required. The accuracy of the method was verified using a swinging impact pendulum. Momentum transfer data between the thrust stand and the pendulum were consistent to within 1%. Following initial calibrations, the stand was used to test a Lincoln Experimental Satellite (LES-8/9) thruster. The LES-8/9 system had a mass of approximately 7.5 kg, with a nominal thrust to weight ratio of 1.3 x 10(exp -5). A total of 34 single shot thruster pulses were individually measured. The average impulse bit per pulse was 266 microN-s, which was slightly less than the value of 300 microN-s published in previous reports on this device. Repetitive pulse measurements were performed similar to ordinary steady-state thrust measurements. The thruster was operated for 30 minutes at a repetition rate of 132 pulses per minute and yielded an average thrust of 573 microN. Using average thrust, the average impulse bit per pulse was estimated to be 260 microN-s, which was in agreement with the single shot data. Zero drift during the repetitive pulse test was found to be approximately 1% of the measured thrust.

Distribution of standing-wave errors in real-ear sound-level measurements.

PubMed

Richmond, Susan A; Kopun, Judy G; Neely, Stephen T; Tan, Hongyang; Gorga, Michael P

2011-05-01

Standing waves can cause measurement errors when sound-pressure level (SPL) measurements are performed in a closed ear canal, e.g., during probe-microphone system calibration for distortion-product otoacoustic emission (DPOAE) testing. Alternative calibration methods, such as forward-pressure level (FPL), minimize the influence of standing waves by calculating the forward-going sound waves separate from the reflections that cause errors. Previous research compared test performance (Burke et al., 2010) and threshold prediction (Rogers et al., 2010) using SPL and multiple FPL calibration conditions, and surprisingly found no significant improvements when using FPL relative to SPL, except at 8 kHz. The present study examined the calibration data collected by Burke et al. and Rogers et al. from 155 human subjects in order to describe the frequency location and magnitude of standing-wave pressure minima to see if these errors might explain trends in test performance. Results indicate that while individual results varied widely, pressure variability was larger around 4 kHz and smaller at 8 kHz, consistent with the dimensions of the adult ear canal. The present data suggest that standing-wave errors are not responsible for the historically poor (8 kHz) or good (4 kHz) performance of DPOAE measures at specific test frequencies.

21 CFR 880.6990 - Infusion stand.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Infusion stand. 880.6990 Section 880.6990 Food and....6990 Infusion stand. (a) Identification. The infusion stand is a stationary or movable stand intended to hold infusion liquids, infusion accessories, and other medical devices. (b) Classification. Class...

21 CFR 880.6990 - Infusion stand.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Infusion stand. 880.6990 Section 880.6990 Food and....6990 Infusion stand. (a) Identification. The infusion stand is a stationary or movable stand intended to hold infusion liquids, infusion accessories, and other medical devices. (b) Classification. Class...

Purification, Characterization, and Cloning of Cinnamyl Alcohol Dehydrogenase in Loblolly Pine (Pinus taeda L.).

PubMed

O'malley, D M; Porter, S; Sederoff, R R

1992-04-01

Cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1. 195) has been purified to homogeneity from differentiating xylem tissue and developing seeds of loblolly pine (Pinus taeda L.). The enzyme is a dimer with a native molecular weight of 82,000 and a subunit molecular weight of 44,000, and is the only form of CAD involved in lignification in differentiating xylem. High levels of loblolly pine CAD enzyme were found in nonlignifying seed tissue. Characterization of the enzyme from both seeds and xylem demonstrated that the enzyme is the same in both tissues. The enzyme has a high affinity for coniferaldehyde (K(m) = 1.7 micromolar) compared with sinapaldehyde (K(m) in excess of 100 micromolar). Kinetic data strongly suggest that coniferin is a noncompetitive inhibitor of CAD enzyme activity. Protein sequences were obtained for the N-terminus (28 amino acids) and for two other peptides. Degenerate oligonucleotide primers based on the protein sequences were used to amplify by polymerase chain reaction a 1050 base pair DNA fragment from xylem cDNA. Nucleotide sequence from the cloned DNA fragment coded for the N-terminal protein sequence and an internal peptide of CAD. The N-terminal protein sequence has little similarity with the lambdaCAD4 clone isolated from bean (MH Walter, J Grima-Pettenati, C Grand, AM Boudet, CJ Lamb [1988] Proc Natl Acad Sci USA 86:5546-5550), which has homology with malic enzyme.

Conservation: Where we stand: Review of Water, land, and people

USGS Publications Warehouse

Leopold, Luna Bergere

1951-01-01

A distinguished conservationist, just returned from more than a year in those Pacific islands held in trust by the United States, reports that representatives of the government there are nearly completely concerned with the maintenance of an administrative organization. Actual advances in matters of land use, of maintaining the material and mental welfare of the native population, and the preservation of the most interesting remnants of untouched habitat, are just never made.Any such oversimplification is, of course, subject to error in detail, but it nevertheless stands as a touchstone to where we stand in conservation. In much more guarded phrases, and with considerable supporting data, Bernard Frank and Anthony Netboy say much the same thing about governmental conservation in the United States in their recently published Water, Land, and People.

Association Mapping of Quantitative Disease Resistance in a Natural Population of Loblolly Pine (Pinus taeda L.)

PubMed Central

Quesada, Tania; Gopal, Vikneswaran; Cumbie, W. Patrick; Eckert, Andrew J.; Wegrzyn, Jill L.; Neale, David B.; Goldfarb, Barry; Huber, Dudley A.; Casella, George; Davis, John M.

2010-01-01

Genetic resistance to disease incited by necrotrophic pathogens is not well understood in plants. Whereas resistance is often quantitative, there is limited information on the genes that underpin quantitative variation in disease resistance. We used a population genomic approach to identify genes in loblolly pine (Pinus taeda) that are associated with resistance to pitch canker, a disease incited by the necrotrophic pathogen Fusarium circinatum. A set of 498 largely unrelated, clonally propagated genotypes were inoculated with F. circinatum microconidia and lesion length, a measure of disease resistance, data were collected 4, 8, and 12 weeks after inoculation. Best linear unbiased prediction was used to adjust for imbalance in number of observations and to identify highly susceptible and highly resistant genotypes (“tails”). The tails were reinoculated to validate the results of the full population screen. Significant associations were detected in 10 single nucleotide polymorphisms (SNPs) (out of 3938 tested). As hypothesized for genes involved in quantitative resistance, the 10 SNPs had small effects and proposed roles in basal resistance, direct defense, and signal transduction. We also discovered associated genes with unknown function, which would have remained undetected in a candidate gene approach constrained by annotation for disease resistance or stress response. PMID:20628037

Power quality improvement of a stand-alone power system subjected to various disturbances

NASA Astrophysics Data System (ADS)

Lone, Shameem Ahmad; Mufti, Mairaj Ud-Din

In wind-diesel stand-alone power systems, the disturbances like random nature of wind power, turbulent wind, sudden changes in load demand and the wind park disconnection effect continuously the system voltage and frequency. The satisfactory operation of such a system is not an easy task and the control design has to take in to account all these subtleties. For maintaining the power quality, generally, a short-term energy storage device is used. In this paper, the performance of a wind-diesel system associated with a superconducting magnetic energy storage (SMES) system is studied. The effect of installing SMES at wind park bus/load bus, on the system performance is investigated. To control the exchange of real and reactive powers between the SMES unit and the wind-diesel system, a control strategy based on fuzzy logic is proposed. The dynamic models of the hybrid power system for most common scenarios are developed and the results presented.

The energy cost for balance control during upright standing.

PubMed

Houdijk, Han; Fickert, Richard; van Velzen, Judith; van Bennekom, Coen

2009-08-01

The aim of this study was to investigate whether balance control during a static upright standing task with and without balance perturbations elicits a significant and meaningful metabolic energy demand and to test whether this energy demand correlates with conventional posturography measures for balance control. Ten healthy subjects were assessed in four 4-min upright standing conditions on a force platform while energy consumption was measured using open circuit respirometry. In the reference condition subjects stood upright in parallel stance without balance perturbation (PS). In the other conditions balance was perturbed by placing the subjects in tandem stance (TS), in tandem stance blind folded (TSBF) and in tandem stance on a balance board (TSBB). Gross and net energy consumption was assessed and various conventional posturography measures were derived from the excursion of the center of pressure (CoP) of the ground reaction force. Energy consumption was substantially affected by all balance perturbations, compared to the reference condition. The highest increase in energy consumption was found for the TSBF condition (increase of 0.86 J kg(-1)s(-1) or 60% of PS). Significant correlations were found between energy consumption and posturography measures. The strongest correlation was found between gross energy consumption and the CoP path and normalized CoP path along the anterior-posterior axis (resp. r=0.57 and r=0.66, p<0.001). It was concluded that the effort for balance control can elicit a meaningful metabolic energy demand. Conventional posturography provided significant, though moderate, predictors of this metabolic effort for balance control.

Desk-based workers' perspectives on using sit-stand workstations: a qualitative analysis of the Stand@Work study.

PubMed

Chau, Josephine Y; Daley, Michelle; Srinivasan, Anu; Dunn, Scott; Bauman, Adrian E; van der Ploeg, Hidde P

2014-07-25

Prolonged sitting time has been identified as a health risk factor. Sit-stand workstations allow desk workers to alternate between sitting and standing throughout the working day, but not much is known about their acceptability and feasibility. Hence, the aim of this study was to qualitatively evaluate the acceptability, feasibility and perceptions of using sit-stand workstations in a group of desk-based office workers. This article describes the qualitative evaluation of the randomized controlled cross-over Stand@Work pilot trial. Participants were adult employees recruited from a non-government health agency in Sydney, Australia. The intervention involved using an Ergotron Workfit S sit-stand workstation for four weeks. After the four week intervention, participants shared their perceptions and experiences of using the sit-stand workstation in focus group interviews with 4-5 participants. Topics covered in the focus groups included patterns of workstation use, barriers and facilitators to standing while working, effects on work performance, physical impacts, and feasibility in the office. Focus group field notes and transcripts were analysed in an iterative process during and after the data collection period to identify the main concepts and themes. During nine 45-min focus groups, a total of 42 participants were interviewed. Participants were largely intrinsically motivated to try the sit-stand workstation, mostly because of curiosity to try something new, interest in potential health benefits, and the relevance to the participant's own and organisation's work. Most participants used the sit-stand workstation and three common usage patterns were identified: task-based routine, time-based routine, and no particular routine. Common barriers to sit-stand workstation use were working in an open plan office, and issues with sit-stand workstation design. Common facilitators of sit-stand workstation use were a supportive work environment conducive to standing

Increased Activity of Rhizosphere and Hyphosphere Enzymes under Elevated CO2 in a Loblolly Pine Stand

NASA Astrophysics Data System (ADS)

Meier, I.; Phillips, R.

2012-12-01

The stimulatory effect of elevated atmospheric CO2 under global climate change on forest productivity has been predicted to decrease over time as pools of available N in soil become depleted, but empirical support for such progressive N limitation has been lacking. Increased N acquisition from soil depleted in inorganic nitrogen requires stimulation of the microbial processing of organic N, possibly through increasing C supply to soil by plant roots or mycorrhizal hyphae. Increases in (mycorr)rhizosphere C fluxes could stimulate microbes to produce extra-cellular enzymes that release N from SOM, feeding back from soil microsites to ecosystem-scale processes. We investigated the influence of elevated CO2 on root exudation and soil enzyme activity at the Duke Forest FACE site, USA, where loblolly pine (Pinus taeda L.) stands have been exposed to elevated CO2 for 14 years and N fertilization for five years. In each plot, root boxes containing acetate windows were installed in 2008. Two years after installation, we collected soils adjacent to root tips (the rhizosphere), hyphal tips (the hyphosphere) and bulk soil. We measured in situ root exudation rates from intact pine roots. Study objectives were to analyze (i) the influence of atmospheric CO2 on root exudation and extra-cellular enzyme activities, (ii) the influence of soil N availability in regulating these activities, and (iii) the relationship between the activities of enzymes involved in N cycling in soils and gross N transformations at soil microsites. Elevated atmospheric CO2 significantly increased the activity of β-1-4-N-acetylglucosaminidase (NAG) in the rhizosphere by almost 2.5 times (39 to 95 nmol h-1 g-1), and 1.6fold in the hyphosphere relative to ambient plots. NAG is an enzyme involved in the degradation of chitin from the cell walls of soil organisms, releasing absorbable forms of nitrogen. The activity of peroxidase, which degrades aromatic C compounds of SOM, increased significantly in the

The effects of spacing and thinning on stand and tree characteristics of 38-year-old loblolly pine

Treesearch

V. Clark Baldwin; Kelly D. Peterson; Alexander Clark; Robert B. Ferguson; Mike R Strub; David R. Bower

2000-01-01

The effects of early and continuous density control on the characteristics of mature loblolly pine (Pinus taedaL.) were measured at age 38 and analyzed. Trees in plots planted at spacings of 1.8 x 1.8, 2.4 x 2.4, 2.7 x 2.7, 3.0 x 3.0, and 3.7 x 3.7 m were either left unthinned or thinned every 5 years beginning at age 18, to...

Lessons from 72 years of monitoring a once-cut pine-hardwood stand on the Crossett Experimental Forest, Arkansas, U.S.A

Treesearch

Don C. Bragg; Michael G. Shelton

2011-01-01

The Crossett Experimental Forest was established in 1934 to provide landowners in the Upper West Gulf Coastal Plain with reliable, science-based advice on how to manage their loblolly (Pinus taeda) and shortleaf (Pinus echinata) pine-dominated forests. A key component of this program was the establishment of an unmanaged control, currently known as the Russell R....

NASA's Functional Task Test: High Intensity Exercise Improves the Heart Rate Response to a Stand Test Following 70 Days of Bedrest

NASA Technical Reports Server (NTRS)

Laurie, Steven S.; Lee, Stuart M. C.; Phillips, Tiffany R.; Dillon, E. Lichar; Sheffield-Moore, Melinda; Urban, Randall J.; Ploutz-Snyder, Lori; Stenger, Michael B.; Bloomberg, Jacob J.

2015-01-01

Cardiovascular adaptations due to spaceflight are modeled with 6deg head-down tilt bed rest (BR) and result in decreased orthostatic tolerance. We investigated if high-intensity resistive and aerobic exercise with and without testosterone supplementation would improve the heart rate (HR) response to a 3.5-min stand test and how quickly these changes recovered following BR. During 70 days of BR male subjects performed no exercise (Control, n=10), high intensity supine resistive and aerobic exercise (Exercise, n=9), or supine exercise plus supplemental testosterone (Exercise+T, n=8; 100 mg i.m., weekly in 2-week on/off cycles). We measured HR for 2 min while subjects were prone and for 3 min after standing twice before and 0, 1, 6, and 11 days after BR. Mixed-effects linear regression models were used to evaluate group, time, and interaction effects. Compared to pre-bed rest, prone HR was elevated on BR+0 and BR+1 in Control, but not Exercise or Exercise+T groups, and standing HR was greater in all 3 groups. The increase in prone and standing HR in Control subjects was greater than either Exercise or Exercise+T groups and all groups recovered by BR+6. The change in HR from prone to standing more than doubled on BR+0 in all groups, but was significantly less in the Exericse+T group compared to the Control, but not Exercise group. Exercise reduces, but does not prevent the increase in HR observed in response to standing. The significantly lower HR response in the Exercise+T group requires further investigation to determine physiologic significance.

Taking Stock and Standing down

ERIC Educational Resources Information Center

Peeler, Tom

2009-01-01

Standing down is an action the military takes to review, regroup, and reorganize. Unfortunately, it often comes after an accident or other tragic event. To stop losses, the military will "stand down" until they are confident they can resume safe operations. Standing down is good for everyone, not just the military. In today's fast-paced world,…

Acclimation of leaf hydraulic conductance and stomatal conductance of Pinus taeda (loblolly pine) to long-term growth in elevated CO2 (free-air CO2 enrichment) and N-fertilizationpce

Treesearch

Jean-Christophe Domec; Sari Palmroth; Eric Ward; Chris Maier; M. Therezien; Ram Oren

2009-01-01

We investigated how leaf hydraulic conductance (Kleaf) of loblolly pine trees is influenced by soil nitrogen amendment (N) in stands subjected to ambient or elevated CO2 concentrations CO2 a and CO2 e, respectively). We also examined how Kleaf varies with changes in reference leaf water potential (...

Support surface related changes in feedforward and feedback control of standing posture.

PubMed

Mohapatra, Sambit; Kukkar, Komal K; Aruin, Alexander S

2014-02-01

The aim of the study was to investigate the effect of different support surfaces on feedforward and feedback components of postural control. Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing on a rigid platform, foam, and wobble board with eyes open or closed. Electrical activity of nine trunk and leg muscles and displacements of the center of pressure were recorded and analyzed during the time frames typical of feedforward and feedback postural adjustments. Feedforward control of posture was characterized by earlier activation of anterior muscles when the subjects stood on foam compared to a wobble board or a firm surface. In addition, the magnitude of feedforward muscle activity was the largest when the foam was used. During the feedback control, anterior muscles were activated prior to posterior muscles irrespective of the nature of surface. Moreover, the largest muscle activity was seen when the supporting surface was foam. Maximum CoP displacement occurred when subjects were standing on a rigid surface. Altering support surface affects both feedforward and feedback components of postural control. This information should be taken into consideration in planning rehabilitation interventions geared towards improvement of balance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Validation of a robotic balance system for investigations in the control of human standing balance.

PubMed

Luu, Billy L; Huryn, Thomas P; Van der Loos, H F Machiel; Croft, Elizabeth A; Blouin, Jean-Sébastien

2011-08-01

Previous studies have shown that human body sway during standing approximates the mechanics of an inverted pendulum pivoted at the ankle joints. In this study, a robotic balance system incorporating a Stewart platform base was developed to provide a new technique to investigate the neural mechanisms involved in standing balance. The robotic system, programmed with the mechanics of an inverted pendulum, controlled the motion of the body in response to a change in applied ankle torque. The ability of the robotic system to replicate the load properties of standing was validated by comparing the load stiffness generated when subjects balanced their own body to the robot's mechanical load programmed with a low (concentrated-mass model) or high (distributed-mass model) inertia. The results show that static load stiffness was not significantly (p > 0.05) different for standing and the robotic system. Dynamic load stiffness for the robotic system increased with the frequency of sway, as predicted by the mechanics of an inverted pendulum, with the higher inertia being accurately matched to the load properties of the human body. This robotic balance system accurately replicated the physical model of standing and represents a useful tool to simulate the dynamics of a standing person. © 2011 IEEE

Influence of Isokinetic Strength Training of Unilateral Ankle on Ipsilateral One-legged Standing Balance of Adults

PubMed Central

Son, Sung Min; Kang, Kyung Woo; Lee, Na Kyung; Nam, Seok Hyun; Kwon, Jung Won; Kim, Kyoung

2013-01-01

[Purpose] The purpose of the current study was to investigate the changes in one-legged standing balance of the ipsilateral lower limb following unilateral isokinetic strength training. [Subjects and Methods] Thirty healthy adult volunteers were randomly assigned to either a training group or a control group, so that each group included 15 subjects. Subjects in the training group performed unilateral ankle isokinetic exercises of the dominant leg using the Biodex 3 PRO System for a period of four weeks. Ipsilateral one-legged standing balance was evaluated before and after the intervention with three stability indexes of balance using the Biodex System: Anterior-Posterior Stability Index (APSI), Medial-Lateral Stability Index (MLSI), and Overall Stability Index (OSI). [Results] Comparison of pre- and post-test data revealed significant improvements in strength values (dorsiflexion, plantarflexion, eversion, and inversion) and stability indexes (APSI, MLSI, OSI). [Conclusion] These results suggest that ankle strengthening exercise can be considered as a form of exercise that may assist individuals with improvement of balance. PMID:24259783

Stand Density and Canopy Gaps

Treesearch

Boris Zeide

2004-01-01

Estimation of stand density is based on a relationship between number of trees and their average diameter in fully stocked stands. Popular measures of density (Reineke’s stand density index and basal area) assume that number of trees decreases as a power function of diameter. Actually, number of trees drops faster than predicted by the power function because the number...

A-3 Test Stand work

NASA Image and Video Library

2011-07-29

Stennis Space Center employees have installed liquid oxygen and liquid hydrogen tanks atop the A-3 Test Stand, raising the structure to its full 300-foot height. The stand is being built to test next-generation rocket engines that could carry humans beyond low-Earth orbit into deep space. The A-3 Test Stand is scheduled for completion and activation in 2013.

Silvicultural treatments in sapling stands

Treesearch

Neil I. Lamson

1989-01-01

Sapling stands are those in which codominant trees average less than 5 inches d.b.h. Silvicultural treatments in sapling stands can be summed up in two words: CROP TREES. Any silvicultural treatment must help crop trees if the investment in sapling stands is going to pay off. Just cutting "bad" or "undesirable" trees does not insure that crop trees...

Static balance according to hip joint angle of unsupported leg during one-leg standing.

PubMed

Cha, Ju-Hyung; Kim, Jang-Joon; Ye, Jae-Gwan; Lee, Seul-Ji; Hong, Jeong-Mi; Choi, Hyun-Kyu; Choi, Ho-Suk; Shin, Won-Seob

2017-05-01

[Purpose] This study aimed to determine static balance according to hip joint angle of the unsupported leg during one-leg standing. [Subjects and Methods] Subjects included 45 healthy adult males and females in their 20s. During one-leg standing on the non-dominant leg, the position of the unsupported leg was classified according to hip joint angles of point angle was class. Static balance was then measured using a force plate with eyes open and closed. The total length, sway velocity, maximum deviation, and velocity on the mediolateral and anteroposterior axes of center of pressure were measured. [Results] In balance assessment with eyes open, there were significant differences between groups according to hip joint angle, except for maximum deviation on the anteroposterior axis. In balance assessment with eyes closed, there were significant differences between total length measurements at 0° and 30°, 60° and between 30° and 90°. There were significant differences between sway velocity measurements at 0° and 30° and between 30° and 90°. [Conclusion] Thus, there were differences in static balance according to hip joint angle. It is necessary to clearly identify the hip joint angle during one-leg standing testing.

NEO Test Stand Analysis

NASA Technical Reports Server (NTRS)

Pike, Cody J.

2015-01-01

A project within SwampWorks is building a test stand to hold regolith to study how dust is ejected when exposed to the hot exhaust plume of a rocket engine. The test stand needs to be analyzed, finalized, and fabrication drawings generated to move forward. Modifications of the test stand assembly were made with Creo 2 modeling software. Structural analysis calculations were developed by hand to confirm if the structure will hold the expected loads while optimizing support positions. These calculations when iterated through MatLab demonstrated the optimized position of the vertical support to be 98'' from the far end of the stand. All remaining deflections were shown to be under the 0.6'' requirement and internal stresses to meet NASA Ground Support Equipment (GSE) Safety Standards. Though at the time of writing, fabrication drawings have yet to be generated, but are expected shortly after.

Effect of revised high-heeled shoes on foot pressure and static balance during standing.

PubMed

Bae, Young-Hyeon; Ko, Mansoo; Park, Young-Soul; Lee, Suk-Min

2015-04-01

[Purpose] The purpose of this study was to investigate the effects of revised high-heeled shoes on the foot pressure ratio and static balance during standing. [Subjects and Methods] A single-subject design was used, 15 healthy women wearing revised high-heeled shoes and general high-heeled shoes in a random order. The foot pressure ratio and static balance scores during standing were measured using a SpaceBalance 3D system. [Results] Forefoot and rearfoot pressures were significantly different between the 2 types of high-heeled shoes. Under the 3 conditions tested, the static balance score was higher for the revised high-heeled shoes than for the general high-heeled shoes, but this difference was not statistically significant. [Conclusion] Revised high-heeled shoes are preferable to general high-heeled shoes, as they result in normalization of normalized foot pressure and a positive effect on static balance.

Effect of revised high-heeled shoes on foot pressure and static balance during standing

PubMed Central

Bae, Young-Hyeon; Ko, Mansoo; Park, Young-Soul; Lee, Suk-Min

2015-01-01

[Purpose] The purpose of this study was to investigate the effects of revised high-heeled shoes on the foot pressure ratio and static balance during standing. [Subjects and Methods] A single-subject design was used, 15 healthy women wearing revised high-heeled shoes and general high-heeled shoes in a random order. The foot pressure ratio and static balance scores during standing were measured using a SpaceBalance 3D system. [Results] Forefoot and rearfoot pressures were significantly different between the 2 types of high-heeled shoes. Under the 3 conditions tested, the static balance score was higher for the revised high-heeled shoes than for the general high-heeled shoes, but this difference was not statistically significant. [Conclusion] Revised high-heeled shoes are preferable to general high-heeled shoes, as they result in normalization of normalized foot pressure and a positive effect on static balance. PMID:25995572

Sit-To-Stand Biomechanics Before and After Total Hip Arthroplasty

PubMed Central

Abujaber, Sumayeh B.; Marmon, Adam R.; Pozzi, Federico; Rubano, James J.; Zeni, Joseph A.

2015-01-01

The purpose of this study was to evaluate changes in movement patterns during a sit-to-stand (STS) task before and after total hip arthroplasty (THA), and to compare biomechanical outcomes after THA to a control group. Forty-five subjects who underwent THA and twenty-three healthy control subjects participated in three-dimensional motion analysis. Pre-operatively, subjects exhibited inter-limb movement asymmetries with lower vertical ground reaction force (VGRF) and smaller moments on the operated limb. Although there were significant improvements in movement symmetry 3 months after THA, patients continued to demonstrate lower VGRF and smaller moments on the operated limb compared to non-operated and to control limbs. Future studies should identify the contributions of physical impairments and the influence of surgical approach on STS biomechanics. PMID:26117068

Thinning ponderosa pine (Pinus ponderosa) stands reduces mortality while maintaining stand productivity

Treesearch

Jianwei Zhang; Martin W. Ritchie; Douglas A. Maguire; William W. Oliver

2013-01-01

We analyzed 45-yr data collected from three ponderosa pine (Pinus ponderosa Lawson & C. Lawson) levels-of-growing-stock installations in Oregon (OR) and northern California (CA), USA, to determine the effect of stand density regimes on stand productivity and mortality. We found that periodic annual increment (PAI) of diameter, basal area (BA...

Evaluation of multiple muscle loads through multi-objective optimization with prediction of subjective satisfaction level: illustration by an application to handrail position for standing.

PubMed

Chihara, Takanori; Seo, Akihiko

2014-03-01

Proposed here is an evaluation of multiple muscle loads and a procedure for determining optimum solutions to ergonomic design problems. The simultaneous muscle load evaluation is formulated as a multi-objective optimization problem, and optimum solutions are obtained for each participant. In addition, one optimum solution for all participants, which is defined as the compromise solution, is also obtained. Moreover, the proposed method provides both objective and subjective information to support the decision making of designers. The proposed method was applied to the problem of designing the handrail position for the sit-to-stand movement. The height and distance of the handrails were the design variables, and surface electromyograms of four muscles were measured. The optimization results suggest that the proposed evaluation represents the impressions of participants more completely than an independent use of muscle loads. In addition, the compromise solution is determined, and the benefits of the proposed method are examined. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Refrigeration system having standing wave compressor

DOEpatents

Lucas, Timothy S.

1992-01-01

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Postural adjustments associated with voluntary contraction of leg muscles in standing man.

PubMed

Nardone, A; Schieppati, M

1988-01-01

The postural adjustments associated with a voluntary contraction of the postural muscles themselves have been studied in the legs of normal standing men. We focussed on the following questions. Do postural adjustments precede the focal movement as in the case of movements of the upper limb? Which muscle(s) are involved in the task of stabilizing posture? Can the same postural muscle be activated in postural stabilization and in voluntary movement at the same time, in spite of the opposite changes in activity possibly required by these conditions? Six subjects standing on a dynamometric platform were asked to rise onto the tips their toes by contracting their soleus muscles, or to rock on their heels by contracting their tibialis anterior muscles. The tasks were made in a reaction time (RT) situation or in a self-paced mode, standing either freely or holding onto a stable structure. Surface EMGs of leg and thigh muscles, and the foot-floor reaction forces were recorded. The following results were obtained in the RT mode, standing freely. 1. Rising onto toe tips: a striking silent period in soleus preceded its voluntary activation; during this silent period, a tibialis anterior burst could be observed in three subjects; these anticipatory activities induced a forward sway, as monitored by a change in the force exerted along the x axis of the platform. 2. Rocking on heels: an enhancement in tonic EMG of soleus was observed before tibialis anterior voluntary burst, at a mean latency from the go-signal similar to that of the silent period; this anticipatory activity induced a backward body sway. 3. Choice RT conditions showed that the above anticipatory patterns in muscle activity were pre-programmed, specific for the intended tasks, and closely associated with the focal movement. When both tasks were performed in a self-paced mode, all the above EMG and mechanical features were more pronounced and unfolded in time. If the subjects held onto the frame, the early

Standing wave compressor

DOEpatents

Lucas, Timothy S.

1991-01-01

A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.

Model for multi-stand management based on structural attributes of individual stands

Treesearch

G.W. Miller; J. Sullivan

1997-01-01

A growing interest in managing forest ecosystems calls for decision models that take into account attribute goals for large forest areas while continuing to recognize the individual stand as a basic unit of forest management. A dynamic, nonlinear forest management model is described that schedules silvicultural treatments for individual stands that are linked by multi-...

Do Sitting, Standing, or Treadmill Desks Impact Psychobiological Indicators of Work Productivity?

PubMed

Gilson, Nicholas D; Hall, Caitlin; Renton, Angela; Ng, Norman; von Hippel, William

2017-10-01

This pilot study investigated the links between psychobiological indicators of work productivity, prolonged desk sitting, and conditions whereby office workers were able to interrupt sitting using a sit-stand or treadmill desk. Twenty participants visited our laboratory and completed their own desk work in counterbalanced sit-only, sit-stand (Varidesk Pro Plus 48™), and sit-walk conditions (Infiniti TR1200-DTS™). Steady-state visually evoked potentials calculated from electroencephalography recordings during a set task at the end of the workday assessed attentional resource. Salivary cortisol samples were taken during the morning and afternoon to measure stress response. Within-subject analyses were used to compare work productivity indicators relative to condition. No significant differences in mean steady-state visually evoked potential amplitude were observed, although attentional resource allocation was found to be the most effective following the sit-stand [1.01 (0.46) μV] compared with the sit-walk [0.9 (0.28) μV] and sit-only [0.91 (0.32) μV] conditions. The mean magnitude of decrease in cortisol was most apparent when workers used treadmill (1.5 nmol/L; P = .007) and sit-stand (1.6 nmol/L; P = .001) desks, and least evident in the sit-only condition (1.0 nmol/L; P = .146). The findings highlight the potential benefits of standing or active deskwork to the allocation of attentional resources and the regulation of stress.

Measurement of transpiration in Pinus taeda L. and Liquidambar styraciflua L. in an environmental chamber using tritiated water

NASA Technical Reports Server (NTRS)

Levy, G. F.; Sonenshine, D. E.; Czoch, J. K.

1976-01-01

Transpiration rates of loblolly pine (Pinus taeda L.) and sweetgum (Liquidambar styraciflua L.) were measured at two different atmospheric water vapor pressure deficits (V.P.D.) in a controlled environment growth chamber using tritiated water as a tracer. The trees were maintained in a sealed plant bed containing a hydroponic nutrient solution into which labeled water (spike) was introduced. Samples of leaves, chamber air, spiked nutrient solution and control water were assayed for ratio-activity using liquid scintillation techniques to determine transpiration rates. The transpiration rate of sweetgum in ml./hr./gm. (4.95) was found to be 5 times greater than that of loblolly pine (1.03) at 1.84 V.P.D. and 8 times greater at 6.74 V.P.D. (15.99 for sweetgum vs. 2.19 for pine). Transpiration (based on measurements of leaf radioactivity) in both species rose with increasing deficit; however sweetgum increased its output by 3 times while pine only doubled its rate. Cyclical changes in transpiration rates were noted in both species; the sweetgum cycle required a 6 hour interval whereas the pine cycle required a 9 hour interval.

The role of the megagametophyte in maintaining loblolly pine (Pinus taeda L.) seedling arginase gene expression in vitro.

PubMed

Todd, Christopher D; Gifford, David J

2002-05-01

Following loblolly pine (Pinus taeda L.) seed germination, storage-protein breakdown in the megagametophyte and in the seedling results in a large increase in the seedling's free amino acid pool. A substantial portion of both the storage proteins and the amino acid pool is arginine, a very efficient nitrogen-storage compound. Free arginine is hydrolyzed in the seedling by the enzyme arginase (EC 3.5.3.1), which is under strong developmental control. At present, regulation of arginase in conifers is not well understood. Here we report the utilization of an in vitro culture system to address the separate impacts of the seedling and megagametophyte tissues on arginase enzyme activity, protein levels and patterns of gene expression. We also describe the generation of an anti-arginase antibody prepared from a histidine-tagged loblolly pine arginase fusion protein expressed in Escherichia coli. Our results indicate that arginase gene expression in the seedling is initiated by the seedling itself and then maintained or up-regulated by the megagametophyte. The contribution of storage-protein breakdown and the free amino acid pool, particularly arginine, in this regulation is also addressed.

The Influence of Residual Stand Densities on Regeneration in Sugar Maple Stands

Treesearch

Carl H. Tubbs

1968-01-01

Studies of regeneration 2, 5, and 10 years after cutting mature and overmature sugar maple stands to several residual densities show that (1) sugar maple is still the predominant species under all stand densities (2) nearly all regeneration reaching larger size classes became established before cutting (3) heavier cuttings (30, 50, and 70 square feet) are more rapidly...

Human voluntary activity integration in the control of a standing-up rehabilitation robot: a simulation study.

PubMed

Kamnik, Roman; Bajd, Tadej

2007-11-01

The paper presents a novel control approach for the robot-assisted motion augmentation of disabled subjects during the standing-up manoeuvre. The main goal of the proposal is to integrate the voluntary activity of a person in the control scheme of the rehabilitation robot. The algorithm determines the supportive force to be tracked by a robot force controller. The basic idea behind the calculation of supportive force is to quantify the deficit in the dynamic equilibrium of the trunk. The proposed algorithm was implemented as a Kalman filter procedure and evaluated in a simulation environment. The simulation results proved the adequate and robust performance of "patient-driven" robot-assisted standing-up training. In addition, the possibility of varying the training conditions with different degrees of the subject's initiative is demonstrated.

Analysis of the impact of a cognitive task on the posture of elderly subjects with depression compared with healthy elderly subjects.

PubMed

Casteran, Matthieu; Putot, Alain; Pfitzenmeyer, François; Thomas, Elizabeth; Manckoundia, Patrick

2016-11-01

While previous studies have demonstrated that depressive elderly subjects (DES) experience difficulties in the processing of simultaneous cognitive tasks, few have examined the coupling of cognitive tasks with seemingly 'automatic' tasks, such as standing upright. Current patient management focuses on pharmacological treatments and cognitive-behavioral therapies. Healthy elderly (HES) and non-treated DES were included. Postural sway in DES was compared with that in HES while in single-task and dual-task conditions. The single-task consisted of standing upright. For the dual-task, the subjects recalled various items from memory or counted while standing upright. Postural sway was evaluated by computing the center of pressure (CoP) area and path length. DES showed greater postural sway than HES in all conditions. The HES showed a greater CoP area in the dual-task than in the single-task conditions. In DES, the CoP area in the single-task condition was similar to that in the dual-task condition. The greater postural sway observed in DES may be a cause of a greater risk of falls. We showed that even seemingly automatic tasks, such as maintaining an upright posture, are affected by depression. These results are important for the management of DES. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Effects of unipedal standing balance exercise on the prevention of falls and hip fracture among clinically defined high-risk elderly individuals: a randomized controlled trial.

PubMed

Sakamoto, Keizo; Nakamura, Toshitaka; Hagino, Hiroshi; Endo, Naoto; Mori, Satoshi; Muto, Yoshiteru; Harada, Atsushi; Nakano, Tetsuo; Itoi, Eiji; Yoshimura, Mitsuo; Norimatsu, Hiromichi; Yamamoto, Hiroshi; Ochi, Takahiro

2006-10-01

The aim of this study was to assess the effectiveness of the unipedal standing balance exercise for 1 min to prevent falls and hip fractures in high-risk elderly individuals with a randomized controlled trial. This control study was designed as a 6-month intervention trial. Subjects included 553 clinically defined high-risk adults who were living in residences or in the community. They were randomized to an exercise group and a control group. Randomization to the subjects was performed by a table of random numbers. A unipedal standing balance exercise with open eyes was performed by standing on each leg for 1 min three times per day. As a rule, subjects of the exercise group stood on one leg without holding onto any support, but unstable subjects were permitted to hold onto a bar during the exercise time. Falls and hip fractures were reported by nurses, physical therapists, or facility staff with a survey sheet every month. This survey sheet was required every month for both groups. Registered subjects were 553 persons ranging in age from 37 to 102 years (average, 81.6 years of age). Twenty-six subjects dropped out. The number of falls and hip fractures for the 6-month period after the trial for 527 of the 553 subjects for whom related data were available were assessed. The exercise group comprised 315 subjects and the control group included 212 subjects. The cumulative number of falls of the exercise group, with 1 multiple faller omitted, was 118, and the control group recorded 121 falls. A significant intergroup difference was observed. However, the cumulative number of hip fractures was only 1 case in both groups. This difference was not statistically significant. The unipedal standing balance exercise is effective to prevent falls but was not shown to be statistically significant in the prevention of hip fracture in this study.

24 CFR 206.37 - Credit standing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CONVERSION MORTGAGE INSURANCE Eligibility; Endorsement Eligible Mortgagors § 206.37 Credit standing. Each mortgagor must have a general credit standing satisfactory to the Secretary. ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Credit standing. 206.37 Section 206...

Three-dimensional instability of standing waves

NASA Astrophysics Data System (ADS)

Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

2003-12-01

We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

A-1 Test Stand modifications

NASA Image and Video Library

2011-09-14

Team members check the progress of a liquid nitrogen cold shock test on the A-1 Test Stand at Stennis Space Center on Sept. 15. The cold shock test is used to confirm the test stand's support system can withstand test conditions, when super-cold rocket engine propellant is piped. The A-1 Test Stand is preparing to conduct tests on the powerpack component of the J-2X rocket engine, beginning in early 2012.

Purification, Characterization, and Cloning of Cinnamyl Alcohol Dehydrogenase in Loblolly Pine (Pinus taeda L.) 1

PubMed Central

O'Malley, David M.; Porter, Stephanie; Sederoff, Ronald R.

1992-01-01

Cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1. 195) has been purified to homogeneity from differentiating xylem tissue and developing seeds of loblolly pine (Pinus taeda L.). The enzyme is a dimer with a native molecular weight of 82,000 and a subunit molecular weight of 44,000, and is the only form of CAD involved in lignification in differentiating xylem. High levels of loblolly pine CAD enzyme were found in nonlignifying seed tissue. Characterization of the enzyme from both seeds and xylem demonstrated that the enzyme is the same in both tissues. The enzyme has a high affinity for coniferaldehyde (Km = 1.7 micromolar) compared with sinapaldehyde (Km in excess of 100 micromolar). Kinetic data strongly suggest that coniferin is a noncompetitive inhibitor of CAD enzyme activity. Protein sequences were obtained for the N-terminus (28 amino acids) and for two other peptides. Degenerate oligonucleotide primers based on the protein sequences were used to amplify by polymerase chain reaction a 1050 base pair DNA fragment from xylem cDNA. Nucleotide sequence from the cloned DNA fragment coded for the N-terminal protein sequence and an internal peptide of CAD. The N-terminal protein sequence has little similarity with the λCAD4 clone isolated from bean (MH Walter, J Grima-Pettenati, C Grand, AM Boudet, CJ Lamb [1988] Proc Natl Acad Sci USA 86:5546-5550), which has homology with malic enzyme. ImagesFigure 2Figure 3 PMID:16668801

Stomatal conductance at Duke FACE: Leveraging the lessons from 11 years of scaled sap flux measurements for region-wide analyses

NASA Astrophysics Data System (ADS)

Ward, E. J.; Bell, D.; Clark, J. S.; McCarthy, H. R.; Kim, H.; domec, J.; Noormets, A.; McNulty, D.; Sun, G.; Oren, R.

2013-12-01

A network of thermal dissipation probes (TDPs) monitoring sap flux density was used to estimate leaf-specific transpiration (EL) and canopy-averaged stomatal conductance (GS) in Pinus taeda (L.) exposed to +200 ppm atmospheric CO2 levels (eCO2) and nitrogen fertilization as part of the Duke FACE study. Data from scaling half-hourly measurements from hundreds of sensors over 11 years indicated that P. taeda in eCO2 intermittently (49% of monthly values) decreased stomatal conductance relative to the control, with a mean reduction of 13% in both total EL and mean daytime GS. This intermittent response was related to changes in a hydraulic allometry index (AH), defined as sapwood area per unit leaf area per unit canopy height, which was linearly related to GS at reference conditions (GSR) during the growing season across years (R2=0.67). Overall, AH decreased a mean of 15% with eCO2 over the course of the study, due mostly to a mean 19% increase in leaf area. Throughout the southeastern U.S., other P. taeda stands have been monitored with TDPs, such as the US-NC2 Ameriflux site and four fertilizer × throughfall displacement studies recently begun as part of the PINEMAP research network in VA, GA, FL and OK. We will also discuss the challenges and benefits of using a common modeling platform to combine FACE TDP data with that from a diversity of sites and treatments to draw inferences about EL and GS responses to environmental drivers and climate change, as well as their relation to AH, across the range of P. taeda.

Effect of yoga training on one leg standing and functional reach tests in obese individuals with poor postural control

PubMed Central

Jorrakate, Chaiyong; Kongsuk, Jutaluk; Pongduang, Chiraprapa; Sadsee, Boontiwa; Chanthorn, Phatchari

2015-01-01

[Purpose] The aim of the present study was to investigate the effect of yoga training on static and dynamic standing balance in obese individuals with poor standing balance. [Subjects and Methods] Sixteen obese volunteers were randomly assigned into yoga and control groups. The yoga training program was performed for 45 minutes per day, 3 times per week, for 4 weeks. Static and dynamic balance were assessed in volunteers with one leg standing and functional reach tests. Outcome measures were tested before training and after a single week of training. Two-way repeated measure analysis of variance with Tukey’s honestly significant difference post hoc statistics was used to analyze the data. [Results] Obese individuals showed significantly increased static standing balance in the yoga training group, but there was no significant improvement of static or dynamic standing balance in the control group after 4 weeks. In the yoga group, significant increases in static standing balance was found after the 2nd, 3rd, and 4th weeks. Compared with the control group, static standing balance in the yoga group was significantly different after the 2nd week, and dynamic standing balance was significantly different after the 4th week. [Conclusion] Yoga training would be beneficial for improving standing balance in obese individuals with poor standing balance. PMID:25642038

Change in subjective social status following HIV diagnosis and associated effects on mental and physical health among HIV-positive gay men in Australia.

PubMed

Heywood, Wendy; Lyons, Anthony

2017-07-01

This study investigates the impact of HIV diagnosis on subjective social status and if changes are linked to health outcomes. Two measures of subjective social status, socio-economic and standing in the community were examined in 342 Australian HIV-positive gay men in 2014. Participants recalled ratings at diagnosis were compared with current ratings. Self-reported mental (psychological distress, self-esteem, positive mental health and satisfaction with life) and physical health (self-rated health, CD4 count, viral load). Half of the participants reported improvements in subjective socio-economic status (59%) or standing in the community (52%) since diagnosis, yet one quarter reported socio-economic status (25%) or standing in the community had decreased (23%). Increases in either measure of subjective social status were linked to higher self-esteem, positive mental health, satisfaction with life and better self-rated health. Decreases in subjective social status, however, were strongly linked to poorer outcomes on all mental health measures. Decreases in standing in the community were also associated with poorer physical self-rated health. Most participants reported their subjective social status were the same or better since diagnosis. Changes in subjective social status following diagnosis were strongly linked to mental health outcomes. Those who reported a decrease in subjective social status were particularly vulnerable to mental health problems.

Dynamic cerebral autoregulation during repeated squat-stand maneuvers

PubMed Central

Claassen, Jurgen A. H. R.; Levine, Benjamin D.; Zhang, Rong

2009-01-01

Transfer function analysis of spontaneous oscillations in blood pressure (BP) and cerebral blood flow (CBF) can quantify the dynamic relationship between BP and CBF. However, such oscillation amplitudes are often small and of questionable clinical significance, vary substantially, and cannot be controlled. At the very low frequencies (<0.07 Hz), coherence between BP and CBF often is low (<0.50) and their causal relationship is debated. Eight healthy subjects performed repeated squat-stand maneuvers to induce large oscillations in BP at frequencies of 0.025 and 0.05 Hz (very low frequency) and 0.1 Hz (low frequency), respectively. BP (Finapres), CBF velocity (CBFV; transcranial Doppler), and end-tidal CO2 (capnography) were monitored. Spectral analysis was used to quantify oscillations in BP and CBFV and to estimate transfer function phase, gain, and coherence. Compared with spontaneous oscillations, induced oscillations had higher coherence [mean 0.8 (SD 0.11); >0.5 in all subjects at all frequencies] and lower variability in phase estimates. However, gain estimates remained unchanged. Under both conditions, the “high-pass filter” characteristics of dynamic autoregulation were observed. In conclusion, using repeated squat-stand maneuvers, we were able to study dynamic cerebral autoregulation in the low frequencies under conditions of hemodynamically strong and causally related oscillations in BP and CBFV. This not only enhances the confidence of transfer function analysis as indicated by high coherence and improved phase estimation but also strengthens the clinical relevance of this method as induced oscillations in BP and CBFV mimic those associated with postural changes in daily life. PMID:18974368

Presyncopal/Non-Presyncopal Outcomes of Post Spaceflight Stand Tests are Consistent from Flight to Flight

NASA Technical Reports Server (NTRS)

Martin, D. S.; Meck, J. V.

2004-01-01

The overall prevalence of orthostatic hypotension after short duration (6-18 d) spaceflight is 20% with existing countermeasures. However, it is not known if the outcomes of stand tests for orthostatic tolerance are consistent within individuals on subsequent flights, or if first time fliers are more (or less) likely to experience orthostatic hypotension and presyncope than are veteran astronauts. Fifty astronauts were studied retrospectively. Stand test data, which had been collected before and after spaceflight, were compared from at least two flights for each astronaut. For twenty-five of these astronauts, their first flight in this database was also their first time to fly into space. For the remaining 25, their first flight in this database was their second, third or fourth flight, as data were available. No subject became presyncopal during preflight testing. Of the 50 subjects, 45 (90%) had the same outcome on their first and second fligh ts of this study. Of 14 subjects on whom we had data from a third mission, 12 had the same stand test outcome on all three flights (86% same outcome across three flights). There was no correlation between flight duration and orthostatic tolerance (r = 0.39). These data support the idea that astronauts are predisposed to orthostatic tolerance/intolerance after spaceflight and that this predisposition is not altered by subsequent flights. Flight durations within this data set did not alter the likelihood of orthostatic intolerance and rookie fliers were no more likely to experience orthostatic intolerance than were veteran astronauts.

Longleaf pine cone production in relation to site index, stand age, and stand density

Treesearch

Thomas Croker

1973-01-01

Few cones were produced in stands less than 30 years old. In stands 30 to 70 years in age, production seemed best at timber densities of about 30 square feet of basal area per acre, and tended to increase with increasing site index.

Goniometric measurement of hip motion in cycling while standing.

PubMed

Hull, M L; Beard, A; Varma, H

1990-01-01

The purpose of this study was to develop an instrument for quantifying the motion of the hip relative to the bicycle while cycling in the standing position. Because of the need to measure hip motion on the road as well as in the laboratory, a goniometer which locates the hip using spherical coordinates was designed. The goniometer is presented first, followed by the development of the equations that enable the distance from the joint center to the pedal spindle to be determined. The orientation of this line segment is specified by calculating two angles referenced to the frame. Also outlined are the procedures used to both calibrate the goniometer and perform an accuracy check. The results of this check indicate that the attachment point of the goniometer to the rider can be located to within 2.5 mm of the true position. The goniometer was used to record the hip movement patterns of six subjects who cycled in the standing position on a treadmill. Representative results from one test subject who cycled at 6% grade and 25 km h-1 are presented. Results indicate that the bicycle is leaned from side to side with the frequency of leaning equal to the frequency of pedalling. Extreme lean angles are +/- 6 degrees. The distance from the hip to the pedal varies approximately sinusoidally with frequency equal to pedalling rate and amplitude somewhat less than crank arm length. The absolute elevation of the hip, however, exhibits two cycles for each crank cycle. Asymmetry in the plot of elevation over a single crank cycle indicates that the pelvis rocks from side to side and that the elevation of the pelvis midpoint changes. Extreme values of the pelvis rocking angle are +/- 12 degrees. Highest pelvis midpoint elevations, however, do not occur at the same crank angles as those angles at which the pelvis rocking is extreme. It appears that the vertical motion of the hips affects pedalling mechanics when cycling in the standing position.

Enhancing wildlife habitat when regenerating stands

Treesearch

Frank R., III Thompson

1989-01-01

Forest regeneration cuttings affect wildlife habitat more drastically than most forest management practices because a mature forest stand is replaced by a young sapling stand. Regeneration cuttings quickly provide habitat for many wildlife species but they also influence wildlife use of the new stand and adjacent areas throughout the rotation. Retaining snags, cavity...

User's Guide to the Stand Prognosis Model

Treesearch

William R. Wykoff; Nicholas L. Crookston; Albert R. Stage

1982-01-01

The Stand Prognosis Model is a computer program that projects the development of forest stands in the Northern Rocky Mountains. Thinning options allow for simulation of a variety of management strategies. Input consists of a stand inventory, including sample tree records, and a set of option selection instructions. Output includes data normally found in stand, stock,...

Effects of trunk-hip strengthening on standing in children with spastic diplegia: a comparative pilot study.

PubMed

Kim, Joong-Hwi; Seo, Hye-Jung

2015-05-01

[Purpose] This study evaluated the effects of trunk-hip strengthening exercise on trunk-hip activation and pelvic tilt motion during standing in children with spastic diplegia and compared the improvement of pelvic tilt between the modified trunk-hip strengthening exercise and conventional exercise. [Subjects and Methods] Ten ambulant children with spastic diplegia were randomized to the modified trunk-hip strengthening exercise (n = 5) or conventional exercise (n = 5) group. The intervention consisted of a 6-week modified trunk-hip strengthening exercise 3 times per week. The children were tested for trunk-hip muscles activation and pelvic tilt motion during standing by surface electromyography and an inclinometer before and after the intervention. [Results] The anterior pelvic tilt angle and activation of the extensor spinae, rectus femoris, and semitendinosus during standing decreased significantly in the modified exercise group. The activation of extensor spinae differed significantly between groups. [Conclusion] Compared to the conventional exercise, the modified exercise was more effective for trunk-hip activation improvement and anterior pelvic tilt motion decrease during standing in children with spastic diplegia. We suggest clinicians use an individually tailored modified trunk-hip strengthening exercise for strengthening the weakest muscle groups in children with standing ability problems.

Quantification of lower extremity physical exposures in various combinations of sit/stand time duration associated with sit-stand workstation.

PubMed

Pei, Huining; Yu, Suihuai; Babski-Reeves, Kari; Chu, Jianjie; Qu, Min; Tian, Baozhen; Li, Wenhua

2017-05-16

Sit-stand workstations are available for office work purposes but there is a dearth of quantitative evidence to state benefits for lower limb outcomes while using them. And there are no guidelines on what constitutes appropriate sit/stand time duration. The primary aim of this study has been to compare muscle activity and perceived discomfort in the lower extremity during various combinations of sit/stand time duration associated with a sit-stand workstation separately and to evaluate the effects of the sit-stand workstation on the lower extremity during the text entry task. During the 5 days, all participants completed a 2-h text entry task each day for various sit/stand time duration combinations as follows: 5/25 min, 10/20 min, 15/15 min, 20/10 min, 25/5 min. Lower extremity muscular exposure of 12 male and 13 female participants was collected at 8 sites by surface electromyography and body discomfort was calculated by a questionnaire under those 5 conditions. Results have demonstrated that lower extremity muscle activity has been significantly varied among the 5 sit/stand time duration groups. Perceived level of discomfort (PLD) has not differed significantly for 9 out of 10 body parts. The muscle activity of the thigh region was influenced by sit/stand time duration significantly. Ergonomic exposures of lower extremity when using a sit-stand workstation were increased, particularly during the long time standing posture. Results indicate that body mass index (BMI) and gender were not significant factors in this study. Combination of sit/stand time duration 25/5 min appears to show positive effects on relief of muscle exposure of back of thigh in the shifts of sitting and standing work position. Med Pr 2017;68(3):315-327. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Ground skidding and harvested stand attributes in Appalachian hardwood stands in West Virginia

Treesearch

Andrew F. Egan; John E. Baumgras

2003-01-01

A statewide logging-in-progress study was conducted in West Virginia to examine the associations among several ground skidding and harvested stand attributes. There was a strong positive association between skidding distance and cycle time, and a significant negative relationship between the percent of trees removed in the stand and total cycle time. The number of...

A-1 Test Stand work

NASA Technical Reports Server (NTRS)

2010-01-01

A structural steel beam to support the new thrust measurement system on the A-1 Test Stand at NASA's John C. Stennis Space Center is lifted to waiting employees for installation. The beam is part of the thrust takeout structure needed to support the new measurement system. Four such beams have been installed at the stand in preparation for installation of the system in upcoming weeks. Operators are preparing the stand for testing the next generation of rocket engines for the U.S. space program.

Pine Forest Harvest Leads to Decade-Scale Alterations in Soil Fungal Communities

NASA Astrophysics Data System (ADS)

Boutton, T. W.; Mushinski, R. M.; Gentry, T. J.

2016-12-01

Forestlands provide a multitude of ecosystem services, and sustainable management is crucial to maintaining the benefits of these ecosystems. Intensive organic matter removal (OMR) of logging residues and forest litter during forest harvest may result in long-term alterations to soil properties and processes. Because fungal activity regulates essential biogeochemical processes in forestlands, changes in soil fungal community structure following OMR may translate into altered soil function. Using a replicated field experiment in southern pine forest in eastern Texas, USA, we sampled soil to a depth of 1 m to assess the impact of intensive OMR on soil fungal communities. Soils were collected from replicated (n = 3 ) loblolly pine (Pinus taeda L.) stands subjected to 3 different harvest intensities (i.e., unharvested old growth stands, bole-only harvest stands, and whole-tree harvest + forest floor removal stands) in 1997. Nearly two decades after trees were harvested and replanted, next generation sequencing of the fungal internal transcribed spacer showed the diversity and community structure of the entire fungal community was altered relative to the unharvested stands. The relative abundance of Ascomycetes increased as OMR intensity increased and was positively correlated to concurrent changes in soil pH. The community composition of fungal functional groups (e.g., ecto- and arbuscular mycorrhizal, saprophytic fungi) was also altered by OMR. The most abundant taxa, Russula exhibited significant reductions in response to increasing intensity of OMR. Results of this study illustrate a linkage between anthropogenically-induced aboveground perturbation, edaphic factors, and belowground soil fungal communities of southern pine forests. Also, these results indicate that tree harvesting effects on soil fungal communities can persist for decades post-harvest, with potential implications for soil functional characteristics.

Stocking, growth, and yield of oak stands

Treesearch

Samuel F. Gingrich

1971-01-01

An appraisal of stocking in even-aged upland oak stands is a prerequisite for determining the cultural needs of a given stand. Most oak stands have sufficient stocking to utilize the site, but are deficient in high-quality trees. Thinning such stands offers a good opportunity to upgrade the relative quality of the growing stock and enhance the growth and yield...

Reconstructed old-growth forest stand structure and composition of two stands on the Olympic Peninsula, Washington state

Treesearch

David H. Peter; Constance A. Harrington

2010-01-01

We reconstructed the stand structure and composition for two western Washington old-growth forest stands harvested around 1930 (named Fresca and Rail) from field and historical data. Both old-growth stands had a codominant or dominant 250-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) overstory with a few scattered older Douglas-fir....

Fine root biomass in relation to site and stand characteristics in Norway spruce and Scots pine stands.

PubMed

Helmisaari, Heljä-Sisko; Derome, John; Nöjd, Pekka; Kukkola, Mikko

2007-10-01

Variations in fine root biomass of trees and understory in 16 stands throughout Finland were examined and relationships to site and stand characteristics determined. Norway spruce fine root biomass varied between 184 and 370 g m(-2), and that of Scots pine ranged between 149 and 386 g m(-2). In northern Finland, understory roots and rhizomes (< 2 mm diameter) accounted for up to 50% of the stand total fine root biomass. Therefore, the fine root biomass of trees plus understory was larger in northern Finland in stands of both tree species, resulting in a negative relationship between fine root biomass and the temperature sum and a positive relationship between fine root biomass and the carbon:nitrogen ratio of the soil organic layer. The foliage:fine root ratio varied between 2.1 and 6.4 for Norway spruce and between 0.8 and 2.2 for Scots pine. The ratio decreased for both Norway spruce and Scots pine from south to north, as well as from fertile to more infertile site types. The foliage:fine root ratio of Norway spruce was related to basal area and stem surface area. The strong positive correlations of these three parameters with fine root nitrogen concentration implies that more fine roots are needed to maintain a certain amount of foliage when nutrient availability is low. No significant relationships were found between stand parameters and fine root biomass at the stand level, but the relationships considerably improved when both fine root biomass and stand parameters were calculated for the mean tree in the stand. When the northern and southern sites were analyzed separately, fine root biomass per tree of both species was significantly correlated with basal area and stem surface area per tree. Basal area, stem surface area and stand density can be estimated accurately and easily. Thus, our results may have value in predicting fine root biomass at the tree and stand level in boreal Norway spruce and Scots pine forests.

Forest Stands Selected by Foraging Red-Cockaded Woodpeckers

Treesearch

Robert G. Hooper; Richard F. Harlow

1986-01-01

Selection of forest stands by 18 clans of foraging red-cockaded woodpeckers was studied in their year-round home ranges. The foraging use of 276 stands relative to their availability within the home ranges was compared to several stand characteristics. Selection among stands with similar characteristics was highly vairable and red-cockadeds foraged in stands with a...

Ammonia oxidizing archaea are the predominant nitrifiers in disturbed and undisturbed southern US pine forests

NASA Astrophysics Data System (ADS)

Mushinski, R. M.; Boutton, T. W.; Gentry, T. J.; Dorosky, R. J.

2016-12-01

The rate-limiting step in nitrification, ammonia oxidation, is performed by both ammonia oxidizing bacteria (AOB) and archaea (AOA); however, reports on the relative contribution of each of these groups to forest soil nitrification has varied. We coupled qPCR and next generation sequencing of the amoA gene to a whole-soil assay that stimulates nitrification and allows for the discrimination of AOA- from AOB-activity using 1-octyne, which inhibits the activity of the bacterial ammonia monooxygenase. Soils, to a depth of 1 meter, were collected from replicated (n = 3) loblolly pine (Pinus taeda L.) stands subjected to three different intensities of timber harvest (i.e., unharvested old growth stands, bole-only harvest stands, and whole-tree harvest + forest floor removal stands). The abundance of both bacterial and archaeal amoA were influenced by harvest method and soil depth; furthermore, archaeal amoA was 13x more abundant than bacterial amoA, across all soil depths. Sequencing and subsequent annotation of the ammonia oxidizing community revealed that the AOA were dominated by Crenarchaeota and AOB were dominated by Nitrosospira. Surface mineral soils (0-10 cm) amended with 1-octyne revealed that approximately 67-86% of total nitrification can be attributable to AOA activity. The highest rates of nitrification (total and 1-octyne resistant) occurred in the soils taken from the unharvested reference stands which were significantly greater than harvested stands. We can conclude that in this pine forest system, AOA dominates AOB in regards to amoA copy number and ammonia oxidizing activity. Not only is this study one of the first to investigate the ammonia-oxidizing population in southern pine forests, but also illustrates that timber harvest can lead to long-term alterations in nitrogen cycle processes.

The selection system of silviculture in spruce-fir stands - procedures, early results, and comparisons with unmanaged stands

Treesearch

Robert M. Frank; Barton M. Blum

1978-01-01

Early results after 20 years of record keeping indicate that spruce-fir stands will respond to the selection system of silviculture. Stand quality is improved, species composition can be altered, diameter-class distribution approaches a stated goal, stand density is controlled, and yields are increased. Selection silviculture in spruce-fir can now be compared to early...

A-3 Test Stand work

NASA Image and Video Library

2011-07-29

Rocket engine propellant tanks and cell dome top the A-3 Test Stand under construction at Stennis Space Center. The stand will test next-generation rocket engines that could carry humans beyond low-Earth orbit into deep space once more.

Red alder stand development and dynamics.

Treesearch

R.L. Deal

2006-01-01

This paper synthesizes information on the development of natural pure red alder stands and dynamics of mixed alder-conifer stands. Early research on red alder growth and yield focused on developing stand volume and normal yield. tables for alder in the Pacific Northwest. Recent site-index estimation and height-growth curves were developed on a 20-year site base age....

A comparison of the community diversity of foliar fungal endophytes between seedling and adult loblolly pines (Pinus taeda)

PubMed Central

Oono, Ryoko; Lefèvre, Emilie; Simha, Anita; Lutzoni, François

2015-01-01

Fungal endophytes represent one of the most ubiquitous plant symbionts on Earth and are phylogenetically diverse. The structure and diversity of endophyte communities have been shown to depend on host taxa and climate, but there have been relatively few studies exploring endophyte communities throughout host maturity. We compared foliar fungal endophyte communities between seedlings and adult trees of loblolly pines (Pinus taeda) at the same seasons and locations by culturing and culture-independent methods. We sequenced the internal transcribed spacer region and adjacent partial large subunit nuclear ribosomal RNA gene (ITS–LSU amplicon) to delimit operational taxonomic units and phylogenetically characterize the communities. Despite the lower infection frequency in seedlings compared to adult trees, seedling needles were receptive to a more diverse community of fungal endophytes. Culture-free method confirmed the presence of commonly cultured OTUs from adult needles but revealed several new OTUs from seedling needles that were not found with culturing methods. The two most commonly cultured OTUs in adults were rarely cultured from seedlings, suggesting that host age is correlated with a selective enrichment for specific endophytes. This shift in endophyte species dominance may be indicative of a functional change between these fungi and their loblolly pine hosts. PMID:26399186

The effects of drought and disturbance on the growth and developmental instability of loblolly pine (Pinus taeda L.)

USGS Publications Warehouse

Graham, John H.; Duda, Jeffrey J.; Brown, Michelle L.; Kitchen, Stanley G.; Emlen, John M.; Malol, Jagadish; Bankstahl, Elizabeth; Krzysik, Anthony J.; Balbach, Harold E.; Freeman, D. Carl

2012-01-01

Ecological indicators provide early warning of adverse environmental change, helping land managers adaptively manage their resources while minimizing costly remediation. In 1999 and 2000, we studied two such indicators, growth and developmental instability, of loblolly pine (Pinus taeda L.) influenced by mechanized infantry training at Fort Benning, Georgia. Disturbed areas were used for military training; tracked and wheeled vehicles damaged vegetation and soils. Highly disturbed sites had fewer trees, diminished ground cover, warmer soils in the summer, and more compacted soils with a shallower A-horizon. We hypothesized that disturbance would decrease the growth of needles, branches, and tree rings, increase the complexity of tree rings, and increase the developmental instability of needles. Contrary to our expectations, however, disturbance enhanced growth in the first year of the study, possibly by reducing competition. In the second year, a drought reduced growth of branches and needles, eliminating the stimulatory effect of disturbance. Growth-ring widths increased with growing-season precipitation, and decreased with growing-season temperature over the last 40 years. Disturbance had no effect on tree-ring complexity, as measured by the Hurst exponent. Within-fascicle variation of current-year needle length, a measure of developmental instability, differed among the study populations, but appeared unrelated to mechanical disturbance or drought.

Wetland biomass crops: Studies in natural and managed stands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, N.J.

1989-01-01

Wetlands dominated by Typha spp. and other emergent macrophytes are some of the most productive natural systems in the temperate zone. The subject of this thesis is the selection and management of potential emergent biomass crops and is presented in the following three chapters: (1) The Productivity of Typha spp. in Managed Stands in Minnesota, (II) The Establishment of Typha spp. on a Northern Minnesota Peatland, and (III) Wetland Species Yield Comparisons. Typha rhizomes were planted in a series of 1.5 m{sup 2} paddies. Variables investigated included planting density, fertilizer application rate and seasonal changes in above and below-ground biomass,more » shoot height and density. Yield increased with increased planting density. Maximum shoot dry weight occurred in August while maximum below ground dry weight was obtained in October. Trial plots were established on a northern Minnesota peatland using both rhizomes and seed. The influence of planting density, substrate preparation and fertilizer application on the seasonal development and productivity of trial plots was investigated. Through extensive literature surveys and sampling natural stands, five species were identified for further screening including: Carex atherodes, Phragmites australis, Scirpus fluviatilis, Sparganium eurycarpum and Spartina pectinata. These species, along with planting stock from five productive Typha stands were planted in 1.5 m{sup 2} paddies to compare productivity and growth characteristics under identical conditions. Trial plots of Phragmites, Scirpus and Sparganium were also established on excavated peatland plots.« less

Interesting times on Krakatau: stand dynamics in the 1990s.

PubMed Central

Whittaker, R J; Partomihardjo, T; Jones, S H

1999-01-01

The Krakatau Islands, Indonesia, have provided an opportunity for ecologists to track primary succession from the 'clean slate' of 1883, through forest closure in the 1920s, to the contemporary period, in which successional changes take the form of alterations in composition and stature of forest stands rather than gross changes in ecosystem type. This paper reports on permanent forest plots established on the islands in 1989, and fully surveyed again in both 1992 and 1997. Since 1989, the plots have been subject to natural disturbance phenomena in the form of varying combinations of, for example, deposition of volcanic ejecta, landslides, lightning strikes, storm damage and drought. These effects have been concentrated between 1992 and 1997, during which the volcano Anak Krakatau has deposited ash on the islands of Sertung and Panjang, but not on Rakata. Data on stand responses are presented for growth rates (dbh (diameter at breast height, 1.3 m) increment), stem recruitment and mortality, biomass changes partitioned into mortality, ingrowth and growth of established trees), and compositional shifts. The discussion focuses on evaluation of questions and successional models framed earlier in the programme. One general finding is that the stand dominants as of 1989 have tended to decline in number within the plots, generally through low levels of recruitment failing to balance rates of mortality. The effects of disturbance to the plots appear to be evident in terms of mortality and recruitment, dbh increment, and changes in biomass. The patterns of change in the eight plots are quite varied, such that relatively few generalizations are possible. The difficulties of establishing meaningful baseline rates for tree growth and stand biomass are discussed. PMID:11605628

Postural response latencies are related to balance control during standing and walking in patients with multiple sclerosis

PubMed Central

Huisinga, Jessie M.; St. George, Rebecca J.; Spain, Rebecca; Overs, Shannon; Horak, Fay B.

2015-01-01

Objective To understand examined the relationship between postural response latencies obtained during postural perturbations and representative measures of balance during standing (sway variables) and during walking (trunk motion). Design Cross-sectional Setting University medical center balance disorders laboratory Participants Forty persons with MS were compared with 20 similar aged control subjects. Twenty subjects with MS had normal walking velocity group and 20 had slow walking velocity based on the 25-foot walk time greater than 5 seconds. Interventions None Main Outcome Measures Postural response latency, sway variables, trunk motion variables Results: We found that subjects with MS with either slow or normal walking velocities had significantly longer postural response latencies than the healthy control group. Postural response latency was not correlated with the 25-ft walk time. Postural response latency was significantly correlated with center of pressure sway variables during quiet standing: root mean square (ρ = 0.334, p=0.040), range (ρ=0.385, p=0.017), mean velocity (ρ=0.337, p=0.038), and total sway area (ρ=0.393, p=0.015). Postural response latency was also significantly correlated with motion of the trunk during walking: sagittal plane range of motion (ρ=0.316, p=0.050) and standard deviation of transverse plane range of motion (ρ=-0.430, p=0.006). Conclusions These findings clearly indicate that slow postural responses to external perturbations in patients with MS contribute to disturbances in balance control, both during standing and walking. PMID:24445088

Impact of direct substitution of arm span length for current standing height in elderly COPD.

PubMed

Pothirat, Chaicharn; Chaiwong, Warawut; Phetsuk, Nittaya

2015-01-01

Arm span length is related to standing height and has been studied as a substitute for current standing height for predicting lung function parameters. However, it has never been studied in elderly COPD patients. To evaluate the accuracy of substituting arm span length for current standing height in the evaluation of pulmonary function parameters and severity classification in elderly Thai COPD patients. Current standing height and arm span length were measured in COPD patients aged >60 years. Postbronchodilator spirometric parameters, forced vital capacity (FVC), forced expiratory volume in first second (FEV1), and ratio of FEV1/FVC (FEV1%), were used to classify disease severity according to global initiative for chronic obstructive lung disease criteria. Predicted values for each parameter were also calculated separately utilizing current standing height or arm span length measurements. Student's t-tests and chi-squared tests were used to compare differences between the groups. Statistical significance was set at P<0.05. A total of 106 COPD patients with a mean age of 72.1±7.8 years, mean body mass index of 20.6±3.8 kg/m(2), and mean standing height of 156.4±8.3 cm were enrolled. The mean arm span length exceeded mean standing height by 7.7±4.6 cm (164.0±9.0 vs 156.4±8.3 cm, P<0.001), at a ratio of 1.05±0.03. Percentages of both predicted FVC and FEV1 values based on arm span length were significantly lower than those using current standing height (76.6±25.4 vs 61.6±16.8, P<0.001 and 50.8±25.4 vs 41.1±15.3, P<0.001). Disease severity increased in 39.6% (42/106) of subjects using arm span length over current standing height for predicted lung function. Direct substitution of arm span length for current standing height in elderly Thai COPD patients should not be recommended in cases where arm span length exceeds standing height by more than 4 cm.

Post-breeding bird responses to canopy tree retention, stand size, and edge in regenerating Appalachian hardwood stands

USGS Publications Warehouse

McDermott, Molly E.; Wood, Petra B.

2011-01-01

Avian use of even-aged timber harvests is likely affected by stand attributes such as size, amount of edge, and retained basal area, all characteristics that can easily be manipulated in timber harvesting plans. However, few studies have examined their effects during the post-breeding period. We studied the impacts of clearcut, low-leave two-age, and high-leave two-age harvesting on post-breeding birds using transect sampling and mist-netting in north-central West Virginia. In our approach, we studied the effects of these harvest types as well as stand size and edge on species characteristic of both early-successional and mature forest habitats. In 2005–2006, 13 stands ranging from 4 to 10 years post-harvest and 4–21 ha in size were sampled from late June through mid-August. Capture rates and relative abundance were similar among treatments for generalist birds. Early-successional birds had the lowest capture rates and fewer species (∼30% lower), and late-successional birds reached their highest abundance and species totals (double the other treatments) in high-leave two-age stands. Area sensitivity was evident for all breeding habitat groups. Both generalist and late-successional bird captures were negatively related to stand size, but these groups showed no clear edge effects. Mean relative abundance decreased to nearly zero for the latter group in the largest stands. In contrast, early-successional species tended to use stand interiors more often and responded positively to stand size. Capture rates for this group tripled as stand size increased from 4 to 21 ha. Few birds in the forest periphery responded to harvest edge types despite within-stand edge effects evident for several species. To create suitable habitat for early-successional birds, large, non-linear openings with a low retained basal area are ideal, while smaller harvests and increased residual tree retention would provide habitat for more late-successional birds post-breeding. Although

Long-term stand growth of interior ponderosa pine stands in response to structural modifications and burning treatments in northeastern California

Treesearch

Justin S. Crotteau; Martin W. Ritchie

2014-01-01

The Blacks Mountain Experimental Research Project created two distinct overstory structural classes (high structural diversity [HiD]; low-structural diversity [LoD]) across 12 stands and subsequently burned half of each stand. We analyzed stand-level growth 10 years after treatment and then modeled individual tree growth to forecast stand-level growth 10–20 years after...

The effects of partial cutting on stand structure and growth of western hemlock—Sitka spruce stands in southeast Alaska.

Treesearch

Robert L. Deal; John C. Tappeiner

2002-01-01

The effects of partial cutting on species composition, new and residual-tree cohorts, tree size distribution, and tree growth was evaluate on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12-96 years ago, when 16-96% if the former stand basal area was removed.Partial cutting maintained stand structures similar to...

A-2 Test Stand modification work

NASA Image and Video Library

2010-10-27

John C. Stennis Space Center employees install a new master interface tool on the A-2 Test Stand on Oct. 27, 2010. Until July 2009, the stand had been used for testing space shuttle main engines. With that test series complete, employees are preparing the stand for testing the next-generation J-2X rocket engine being developed. Testing of the new engine is scheduled to begin in 2011.

[Effects of crop tree release on stand growth and stand structure of Cunninghamia lanceolata plantation].

PubMed

Wu, Jian-qiang; Wang, Yi-xiang; Yang, Yi; Zhu, Ting-ting; Zhu, Xu-dan

2015-02-01

Crop trees were selected in a 26-year-old even-aged Cunninghamia lanceolata plantation in Lin' an, and compared in plots that were released and unreleased to examine growth and structure responses for 3 years after thinning. Crop tree release significantly increased the mean increments of diameter and volume of individual tree by 1.30 and 1.25 times relative to trees in control stands, respectively. The increments of diameter and volume of crop trees were significantly higher than those of general trees in thinning plots, crop trees and general trees in control plots, which suggested that the responses from different tree types to crop tree release treatment were different. Crop tree release increased the average distances of crop trees to the nearest neighboring trees, reducing competition among crop trees by about 68.2%. 3-year stand volume increment for thinning stands had no significant difference with that of control stands although the number of trees was only 81.5% of the control. Crop trees in thinned plots with diameters over than 14 cm reached 18.0% over 3 years, compared with 12.0% for trees without thinning, suggesting that crop tree release benefited the larger individual trees. The pattern of tree locations in thinning plots tended to be random, complying with the rule that tree distribution pattern changes with growth. Crop tree release in C. lanceolata plantation not only promoted the stand growth, but also optimized the stand structure, benefiting crop trees sustained rapid growth and larger diameter trees production.

Biomass estimation for Virginia pine trees and stands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madgwick, H.A.I.

1980-03-01

Stands of Virginia Pine (Pinus virginiana Mill.) occur on much abandoned farm land in the Appalachian Mountains and Piedmont of Virginia. Natural stands are an important source of pulpwood, and these are being augmented by plantations. Increased intensity of utilization necessitates the estimation of component weights of the trees. Data from 501 trees from 10 stands were used to develop equations for estimating dry weight of stem wood, stem bark, total stem 1-year-old needles, total needles, live branches, and total branches of individual trees. Stand weight of stems was closely related to stand basal area and mean height. Stand live-branchmore » weight varies inversely with stocking. Weight of 1-year-old foliage on the stands increased with stocking and site index. 13 references.« less

Predicting breeding bird occurrence by stand- and microhabitat-scale features in even-aged stands in the Central Appalachians

USGS Publications Warehouse

McDermott, M.E.; Wood, P.B.; Miller, G.W.; Simpson, B.T.

2011-01-01

Spatial scale is an important consideration when managing forest wildlife habitat, and models can be used to improve our understanding of these habitats at relevant scales. Our objectives were to determine whether stand- or microhabitat-scale variables better predicted bird metrics (diversity, species presence, and abundance) and to examine breeding bird response to clearcut size and age in a highly forested landscape. In 2004-2007, vegetation data were collected from 62 even-aged stands that were 3.6-34.6. ha in size and harvested in 1963-1990 on the Monongahela National Forest, WV, USA. In 2005-2007, we also surveyed birds at vegetation plots. We used classification and regression trees to model breeding bird habitat use with a suite of stand and microhabitat variables. Among stand variables, elevation, stand age, and stand size were most commonly retained as important variables in guild and species models. Among microhabitat variables, medium-sized tree density and tree species diversity most commonly predicted bird presence or abundance. Early successional and generalist bird presence, abundance, and diversity were better predicted by microhabitat variables than stand variables. Thus, more intensive field sampling may be required to predict habitat use for these species, and management may be needed at a finer scale. Conversely, stand-level variables had greater utility in predicting late-successional species occurrence and abundance; thus management decisions and modeling at this scale may be suitable in areas with a uniform landscape, such as our study area. Our study suggests that late-successional breeding bird diversity can be maximized long-term by including harvests >10. ha in size into our study area and by increasing tree diversity. Some harvesting will need to be incorporated regularly, because after 15 years, the study stands did not provide habitat for most early successional breeding specialists. ?? 2010 Elsevier B.V.

Stand development and yields of Appalachian hardwood stands managed with single-tree selection for at least 30 years

Treesearch

Neil I Lamson; H. Clay Smith; H. Clay Smith

1991-01-01

Appalachian hardwood stands in West Virginia were managed for 30 or more years using single-tree selection regeneration practices. Stand yield data suggest that current stand growth will provide economical harvest cuts for several future cutting cycles. This case study indicates that the single-tree selection practice has potential for landowners who want to maintain...

Stand quality management in a late-rotation, red oak-sweetgum stand in east Mississippi: preliminary results following thinning

Treesearch

James S. Meadows; Daniel A. Skojac

2012-01-01

Stand quality management is a new management strategy in which thinning prescriptions are based solely on tree quality rather than a quantitative level of residual stand density. As long as residual density falls within fairly broad limits, prescriptions are based on tree quality alone. We applied four thinning prescriptions based on stand quality management, along...

Influence of prolonged wearing of unstable shoes on upright standing postural control.

PubMed

Sousa, Andreia S P; Macedo, Rui; Santos, Rubim; Sousa, Filipa; Silva, Andreia; Tavares, João Manuel R S

2016-02-01

To study the influence of prolonged wearing of unstable shoes on standing postural control in prolonged standing workers. The participants were divided into two groups: one wore unstable shoes while the other wore conventional shoes for 8weeks. Stabilometry parameters related to centre of pressure (CoP), rambling (RM) and trembling (TR) as well as the total agonist/antagonist muscle activity, antagonist co-activation and reciprocal activation were evaluated during upright standing, before and after the 8weeks period. In both moments, the subjects were evaluated wearing the unstable shoes and in barefoot. The unstable shoe condition presented increased CoP displacement related variables and decreased co-activation command compared to barefoot before and after the intervention. The prolonged wearing of unstable shoes led to: (1) reduction of medial-lateral CoP root mean square and area; (2) decreased anteroposterior RM displacement; (3) increased anteroposterior RM mean velocity and mediolateral RM displacement; (4) decreased anteroposterior TR RMS; and (5) increased thigh antagonist co-activation in the unstable shoe condition. The unstable shoe condition is associated to a higher destabilising effect that leads to a selection of more efficient and accurate postural commands compared to barefoot. Prolonged wearing of unstable shoes provides increased effectiveness and performance of the postural control system, while wearing of unstable shoes in upright standing, that are reflected by changes in CoP related variables and by a reorganisation of postural control commands. Copyright © 2015 Elsevier B.V. All rights reserved.

21 CFR 203.35 - Standing requests.

Code of Federal Regulations, 2011 CFR

2011-04-01

... PRESCRIPTION DRUG MARKETING Samples § 203.35 Standing requests. Manufacturers or authorized distributors of... subsequent oral communication or electronic transmission, is not considered to be a standing request. ...

Seasonal Biennial Burning and Woody Plant Control Influence Native Vegetation in Loblolly Pine Stands

Treesearch

James D. Haywood; Alton Martin; Henry A. Pearson; Harold E. Grelen

1998-01-01

This paper documents the results of a study to determine the effects of selectedvegetation-management treatments in loblolly pine. Vegetation in precommercially thinned, 6-year-old stands was subjected to five biennial growing season burns in either early March, May, or July coupled with hand felling of residual woody stems. Using a randomized complete block design, we...

Quantifying Standing Dead Tree Volume and Structural Loss with Voxelized Terrestrial Lidar Data

NASA Astrophysics Data System (ADS)

Popescu, S. C.; Putman, E.

2017-12-01

Standing dead trees (SDTs) are an important forest component and impact a variety of ecosystem processes, yet the carbon pool dynamics of SDTs are poorly constrained in terrestrial carbon cycling models. The ability to model wood decay and carbon cycling in relation to detectable changes in tree structure and volume over time would greatly improve such models. The overall objective of this study was to provide automated aboveground volume estimates of SDTs and automated procedures to detect, quantify, and characterize structural losses over time with terrestrial lidar data. The specific objectives of this study were: 1) develop an automated SDT volume estimation algorithm providing accurate volume estimates for trees scanned in dense forests; 2) develop an automated change detection methodology to accurately detect and quantify SDT structural loss between subsequent terrestrial lidar observations; and 3) characterize the structural loss rates of pine and oak SDTs in southeastern Texas. A voxel-based volume estimation algorithm, "TreeVolX", was developed and incorporates several methods designed to robustly process point clouds of varying quality levels. The algorithm operates on horizontal voxel slices by segmenting the slice into distinct branch or stem sections then applying an adaptive contour interpolation and interior filling process to create solid reconstructed tree models (RTMs). TreeVolX estimated large and small branch volume with an RMSE of 7.3% and 13.8%, respectively. A voxel-based change detection methodology was developed to accurately detect and quantify structural losses and incorporated several methods to mitigate the challenges presented by shifting tree and branch positions as SDT decay progresses. The volume and structural loss of 29 SDTs, composed of Pinus taeda and Quercus stellata, were successfully estimated using multitemporal terrestrial lidar observations over elapsed times ranging from 71 - 753 days. Pine and oak structural loss rates

Cooperative standing-horizontal-standing reentrant transition for numerous solid particles under external vibration.

PubMed

Takatori, Satoshi; Baba, Hikari; Ichino, Takatoshi; Shew, Chwen-Yang; Yoshikawa, Kenichi

2018-01-11

We report the collective behavior of numerous plastic bolt-like particles exhibiting one of two distinct states, either standing stationary or horizontal accompanied by tumbling motion, when placed on a horizontal plate undergoing sinusoidal vertical vibration. Experimentally, we prepared an initial state in which all of the particles were standing except for a single particle that was placed at the center of the plate. Under continuous vertical vibration, the initially horizontal particle triggers neighboring particles to fall over into a horizontal state through tumbling-induced collision, and this effect gradually spreads to all of the particles, i.e., the number of horizontal particles is increased. Interestingly, within a certain range of vibration intensity, almost all of the horizontal particles revert back to standing in association with the formation of apparent 2D hexagonal dense-packing. Thus, phase segregation between high and low densities, or crystalline and disperse domains, of standing particles is generated as a result of the reentrant transition. The essential features of such cooperative dynamics through the reentrant transition are elucidated with a simple kinetic model. We also demonstrate that an excitable wave with the reentrant transition is observed when particles are situated in a quasi-one-dimensional confinement on a vibrating plate.

Attenuated or absent HRV response to postural change in subjects with primary insomnia.

PubMed

Jiang, Xiao-ling; Zhang, Zheng-gang; Ye, Cui-ping; Lei, Ying; Wu, Lei; Zhang, Ying; Chen, Yuan-yuan; Xiao, Zhong-ju

2015-03-01

Previous studies have compared rest heart rate variability (HRV) between insomniacs and good sleepers, but the results have not been consistent. The altered HRV behavior in response to postural change was considered useful as another sensitive measure for evaluating the autonomic nervous function, however, to our knowledge, no study was found using HRV response to postural change in primary insomnia. Our study aimed to examine HRV response to postural change maneuver (PCM) in both primary insomniacs and controls between 22 and 39 years of age to gain insights into the characteristics of the autonomic nervous system (ANS) function in primary insomnia subjects. HRV was recorded for 5 min at seated rest, and then, the subjects quickly stood up from a seated position in up to 3s and remained standing for 15 min. HRV was recorded at the following times: seated rest and 0-5 min, 5-10 min and 10-15 min in the standing position. In primary insomnia subjects, attenuated or absent HRV response to postural change was identified, the increase in LF/HF ratio and the decrease in HF and SD1 from seated to standing were much slower than in the normal controls. In conclusion, this study provided evidence of the possible bi-directional relationship between insomnia and autonomic nervous system (ANS) function, which will move us closer to developing a new sensitive method for measuring autonomic impairment and early sympathetic damage in primary insomnia subjects. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis.

PubMed

Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

2017-01-01

Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12-18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis

PubMed Central

Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

2017-01-01

Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12–18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

Diameter Distributions in Natural Yellow-Poplar Stands

Treesearch

Charles E. McGee; Lino Della-Bianca

1967-01-01

Diameter distributions obtained from 141 pure, natural unthinned yellow-poplar stands in the Appalachian Mountains of Virginia, North Carolina, and Georgia are presented in tables. The distributions are described in relation to stand age, site index, and total number of trees per acre, and are useful for stand management planning.

Snow breakage in a pole-sized ponderosa pine plantation ... more damage at high stand-densities

Treesearch

Robert F. Powers; William W. Oliver

1970-01-01

Damage by snow breakage to pole-sized ponderosa pine (Pinus pondvosa Laws.) increased as stand density increased. In a plantation on the west slope of California's Sierra Nevada, the tallest trees were most often broken. Thinning in the sapling stage is recommended as a preventative measure in dense plantations subject to heavy snowfall.

21 CFR 880.2700 - Stand-on patient scale.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Devices § 880.2700 Stand-on patient scale. (a) Identification. A stand-on patient scale is a device intended for medical purposes that is used to weigh a patient who is able to stand on the scale platform... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stand-on patient scale. 880.2700 Section 880.2700...

Advance reproduction and other stand characteristics in Pennsylvania and French stands of northern red oak

Treesearch

Kim C. Steiner; Marc D. Abrams; Todd W. Bowersox

1993-01-01

The frequent scarcity of northern red oak (NRO) advance reproduction raises questions about its regeneration potential under prevailing stand conditions in eastern North America. In contrast, NRO plantations in France typically contain abundant advance reproduction. The purpose of this study was to document stand conditions in Pennsylvania (PA) and southwestern France...

Economic considerations of managing stands

Treesearch

Gary W. Miller

1989-01-01

Managing central hardwood stands involves making choices. Each year landowners face at least three alternatives for managing a stand: (1) allow it to grow undisturbed, (2) undertake a partial or complete commercial harvest, or (3) culture the timber crop through a precommercial investment. Each activity affects long-term monetary returns. The "best" choice in...

The effects of stand structure after thinning on the growth of an Allegheny hardwood stand

Treesearch

David A. Marquis; Richard L. Ernst

1991-01-01

A 50-year-old Allegheny hardwood stand in which the crown canopy had stratified into distinct species groups was thinned to 60% relative density leaving dramatically different stand structures and species composition. Treatments included combined thinning, thin from middle, thin from above, thin from below, and unthinned control. Individual tree growth was stimulated...

Vegetation Recovery and Stand Structure Following a Prescribed Stand-Replacement Burn in Sand Pine Scrub

Treesearch

Cathryn H. Greenberg

2003-01-01

Vegetation and stand structure of sand pine scrub in central Florida, USA, were measured before a prescribed stand-replacement burn and for > 8 y afterward. Herbaceous species richness peaked within 16 months postburn, then gradually declined, although significant differences were detected only between 16 months and > 8 y postburn. Twenty-two plant species...

Dynamics of dense direct-seeded stands of southern pines

Treesearch

J.C.G. Goelz

2006-01-01

Direct seeding of southern pines is an effective method of artificial regeneration, producing extremely dense stands when survival exceeds expectations. Long-term studies of dense direct-seeded stands provide ideal data for exploring development of stands as they approach the limit of maximum stand density. I present data from seven studies with ages of stands ranging...

Silvicultural systems for harvesting mixed hardwood stands

Treesearch

H. Clay Smith; Ivan L. Sander

1989-01-01

Mixed stands that include oaks, yellow-poplar, black cherry, maples, white ash, basswood, birches, American beech, and other species are commonly found in the central hardwood forest. Depending on site quality and past stand treatment, overstory composition may range from nearly pure stands of oak or yellow-poplar to mixtures of 20 or more species.

Dynamics of Connecticut hemlock stands

Treesearch

Jeffrey S. Ward; David M. Smith

2000-01-01

The stand dynamics and production of two one-acre plots of eastern hemlock (Tsuga canadensis L) in Connecticut have been followed for more than six decades. Data were recorded for all individual trees. One plot (Saltonstall) was established in 1924 after the removal of a hardwood overstory. This stand had a nearly pure, almost fully closed understory...

Experimental Studies of Discrimination in the Evaluation of Job Applicants' Resumes: I. Relative Importance of Sex, Attractiveness, and Scholastic Standing. Paper No. 430.

ERIC Educational Resources Information Center

Wiback, Kent; And Others

College students and college recruiters rated bogus resumes of twelve senior industrial management students who were allegedly seeking employment. In addition to subject population, three variables were systematically varied in each resume: applicant's sex, physical attractiveness, and scholastic standing. The dependent variable was subjects'…

Stand hazard rating for central Idaho forests

Treesearch

Robert Steele; Ralph E. Williams; Julie C. Weatherby; Elizabeth D. Reinhardt; James T. Hoffman; R. W. Thier

1996-01-01

Growing concern over sustainability of central ldaho forests has created a need to assess the health of forest stands on a relative basis. A stand hazard rating was developed as a composite of 11 individual ratings to compare the health hazards of different stands. The composite rating includes Douglas-fir beetle, mountain pine beetle, western pine beetle, spruce...

A-3 Test Stand work continues

NASA Image and Video Library

2011-04-22

Stennis Space Center employees continue work on the A-3 Test Stand test cell. The stand is being built to test next-generation rocket engines that could carry humans beyond low-Earth orbit into deep space.

Sensor Fusion to Infer Locations of Standing and Reaching Within the Home in Incomplete Spinal Cord Injury.

PubMed

Lonini, Luca; Reissman, Timothy; Ochoa, Jose M; Mummidisetty, Chaithanya K; Kording, Konrad; Jayaraman, Arun

2017-10-01

The objective of rehabilitation after spinal cord injury is to enable successful function in everyday life and independence at home. Clinical tests can assess whether patients are able to execute functional movements but are limited in assessing such information at home. A prototype system is developed that detects stand-to-reach activities, a movement with important functional implications, at multiple locations within a mock kitchen. Ten individuals with incomplete spinal cord injuries performed a sequence of standing and reaching tasks. The system monitored their movements by combining two sources of information: a triaxial accelerometer, placed on the subject's thigh, detected sitting or standing, and a network of radio frequency tags, wirelessly connected to a wrist-worn device, detected reaching at three locations. A threshold-based algorithm detected execution of the combined tasks and accuracy was measured by the number of correctly identified events. The system was shown to have an average accuracy of 98% for inferring when individuals performed stand-to-reach activities at each tag location within the same room. The combination of accelerometry and tags yielded accurate assessments of functional stand-to-reach activities within a home environment. Optimization of this technology could simplify patient compliance and allow clinicians to assess functional home activities.

Stand-structural effects on Heterobasidion abietinum-related mortality following drought events in Abies pinsapo.

PubMed

Linares, Juan Carlos; Camarero, Jesús Julio; Bowker, Matthew A; Ochoa, Victoria; Carreira, José Antonio

2010-12-01

Climate change may affect tree-pathogen interactions. This possibility has important implications for drought-prone forests, where stand dynamics and disease pathogenicity are especially sensitive to climatic stress. In addition, stand structural attributes including density-dependent tree-to-tree competition may modulate the stands' resistance to drought events and pathogen outbreaks. To assess the effects of stand structure on root-rot-related mortality after severe droughts, we focused on Heterobasidion abietinum mortality in relict Spanish stands of Abies pinsapo, a drought-sensitive fir. We compared stand attributes and tree spatial patterns in three plots with H. abietinum root-rot disease and three plots without root-rot. Point-pattern analyses were used to investigate the scale and extent of mortality patterns and to test hypotheses related to the spread of the disease. Dendrochronology was used to date the year of death and to assess the association between droughts and growth decline. We applied a structural equation modelling approach to test if tree mortality occurs more rapidly than predicted by a simple distance model when trees are subjected to high tree-to-tree competition and following drought events. Contrary to expectations of drought mortality, the effect of precipitation on the year of death was strong and negative, indicating that a period of high precipitation induced an earlier tree death. Competition intensity, related to the size and density of neighbour trees, also induced an earlier tree death. The effect of distance to the disease focus was negligible except in combination with intensive competition. Our results indicate that infected trees have decreased ability to withstand drought stress, and demonstrate that tree-to-tree competition and fungal infection act as predisposing factors of forest decline and mortality.

Power roll gin stand technology: Evaluation and optimization of rib rail angle and ginning point modifications on a retrofitted Lummus gin stand

USDA-ARS?s Scientific Manuscript database

Previous studies have shown the powered roll gin stand (PRGS) is capable of improving ginning rate, turnout, and fiber quality relative to a conventional gin stand; however, most of these studies used Continental Eagle gin stands, the gin stand used to develop the initial prototype and the one used ...

Center of pressure velocity reflects body acceleration rather than body velocity during quiet standing.

PubMed

Masani, Kei; Vette, Albert H; Abe, Masaki O; Nakazawa, Kimitaka

2014-03-01

The purpose of this study was to test the hypothesis that the center of pressure (COP) velocity reflects the center of mass (COM) acceleration due to a large derivative gain in the neural control system during quiet standing. Twenty-seven young (27.2±4.5 years) and twenty-three elderly (66.2±5.0 years) subjects participated in this study. Each subject was requested to stand quietly on a force plate for five trials, each 90 s long. The COP and COM displacements, the COP and COM velocities, and the COM acceleration were acquired via a force plate and a laser displacement sensor. The amount of fluctuation of each variable was quantified using the root mean square. Following the experimental study, a simulation study was executed to investigate the experimental findings. The experimental results revealed that the COP velocity was correlated with the COM velocity, but more highly correlated with the COM acceleration. The equation of motion of the inverted pendulum model, however, accounts only for the correlation between the COP and COM velocities. These experimental results can be meaningfully explained by the simulation study, which indicated that the neural motor command presumably contains a significant portion that is proportional to body velocity. In conclusion, the COP velocity fluctuation reflects the COM acceleration fluctuation rather than the COM velocity fluctuation, implying that the neural motor command controlling quiet standing posture contains a significant portion that is proportional to body velocity. Copyright © 2013 Elsevier B.V. All rights reserved.

Early dynamics of table mountain pine stands following stand-replacement prescribed fires of varying intensity

Treesearch

Thomas A. Waldrop; Helen H. Mohr; Patrick H. Brose

2006-01-01

Interest in using stand-replacement prescribed fires to regenerate stands of Table Mountain pine (Pinus pungens Lamb.) has increased in the past decade, but the type and intensity of fire needed to achieve success have been undefined. In an earlier paper, we concluded from first-year results that flames must reach into the crowns to kill most...

Stand dynamics in 60-year-old Allegheny hardwoods after thinning

Treesearch

Gary W. Miller

1997-01-01

Stand dynamics and tree growth in even-aged hardwood stands can be influenced by manipulating relative stand density, species composition, and stand structure. Land managers need quantitative information on the effect of vegetation manipulation to prescribe stand treatments that are appropriate for specific management objectives. Sixty-year-old stands composed of black...

Stand characteristics of 65-year-old planted and naturally regenerated stands near Sequim, Washington. Forest Service research paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, R.E.; Anderson, H.W.

1995-04-01

Tree numbers, height, and volume were determined in six 63- to 66-year-old plantations of coast Douglas-fir (Pseudotsunga menziesii) (Mirb.) Franco var. menziesii in northwest Washington. These stands resulted from the first extensive plantings of this species in the Pacific Northwest. Data from 0.25-acre plots in these plantations were compared to those from matched plots in adjacent, naturally regenerated stands with the same history of logging, wildfire, and absence of further siviculture after regeneration. Planting resulted in well-stocked Douglas-fir stands with volunteers of other tree species. Natural seeding resulted in similarly stocked stands of western hemlock (Tsunga heterophylla) (Raf.) (Sarg.) withmore » Douglas-fir in the dominant crown class.« less

Response of sapling stands to cultural treatments

Treesearch

H. Clay Smith

1989-01-01

The main reasons for precommercial cultural practices in sapling stands (trees less than 5 inches d.b.h.) are to increase growth of residual trees, increase stand value, and improve or maintain species composition. On good sites (northern red oak site index 70 and above), treating sapling stands may be justified by increased diameter growth of high value species. On...

Estimating growth and yield of mixed stands

Treesearch

Stephen R. Shifley; Burnell C. Fischer

1989-01-01

A mixed stand is defined as one in which no single species comprises more than 80 percent of the stocking. The growth estimation methods described below can be used not only in mixed stands but in almost any stand, regardless of species composition, age structure, or size structure. The methods described are necessary to accommodate the complex species mixtures and...

Evaluation of the kinetic energy of the torso by magneto-inertial measurement unit during the sit-to-stand movement.

PubMed

Lepetit, Kevin; Ben Mansour, Khalil; Boudaoud, Sofiane; Kinugawa-Bourron, Kiyoka; Marin, Frédéric

2018-01-23

Sit-to-stand tests are used in geriatrics as a qualitative issue in order to evaluate motor control and stability. In terms of measured indicators, it is traditionally the duration of the task that is reported, however it appears that the use of the kinetic energy as a new quantitative criterion allows getting a better understanding of musculoskeletal deficits of elderly subjects. The aim of this study was to determine the feasibility to obtain the measure of kinetic energy using magneto-inertial measurement units (MIMU) during sit-to-stand movements at various paces. 26 healthy subjects contributed to this investigation. Measured results were compared to a marker-based motion capture using the correlation coefficient and the normalized root mean square error (nRMSE). nRMSE were below 10% and correlation coefficients were over 0.97. In addition, errors on the mean kinetic energy were also investigated using Bland-Altman 95% limits of agreement (0.63 J-0.77 J), RMSE (0.29 J-0.38 J) and correlation coefficient (0.96-0.98). The results obtained highlighted that the method based on MIMU data could be an alternative to optoelectronic data acquisition to assess the kinetic energy of the torso during the sit-to-stand test, suggesting this method as being a promising alternative to determine kinetic energy during the sit-to-stand movement. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of intermittent standing and walking on physiological changes induced by head-down bed rest

NASA Technical Reports Server (NTRS)

Vernikos, J.; Ludwig, D. A.; Ertl, A. C.; Wade, C. E.; Keil, L.; OHara, D.

1994-01-01

Continuous exposure to gravity may not be necessary to prevent compromised physiological function resulting from exposure to microgravity. However, minimum gravity (G) exposure requirements, effectiveness of passive Gz versus activity in a G field, and optimal G stimulus amplitude, duration, and frequency are unknown. To partially address these questions, a 4-day, 6 degree head-down bed rest (HDBR) study (one ambulatory control day, 4 full HDBR days, one recovery day) was conducted. Nine males, 30-50 yr, were subjected to four different +1 Gz (head-foot) exposure protocols (periodic standing or controlled walking for 2 or 4 h/day in 15 min doses), plus a continuous HDBR (0 Gz) control. Standing 4 h completely prevented and standing 2 h partially prevented post-HDBR orthostatic intolerance. Both walking conditions (2 h and 4 h) attenuated the decrease in peak VO2 and prevented the increased urinary Ca2+ excretion associated with HDBR. Both 4 h conditions (standing and walking) attenuated plasma volume loss during HDBR. It was concluded that various physiological systems benefit differentially from passive +1 Gz or activity in +1 Gz and the duration (2 h vs. 4 h) of the stimulus may be an important moderating factor.

Changes in site productivity and the recovery of soil properties following wet- and dry-weather harvesting disturbances in the Atlantic Coastal Plain for a stand of age 10 years

Treesearch

Mark H. Eisenbies; James A. Burger; Aust W. Michael; Patterson Steven C.

2007-01-01

Wet-weather logging can cause severe soil physical disturbances and redistribute residues. Although some research indicates negative effects of such disturbances on individual tree growth, the long-tenn resilience and resistance of soils and the ameliorative effects of site preparation are not fully understood. Three 20 ha loblolly pine (Pinus taeda L....

Converting partially-stocked aspen stands to fully-stocked stands in the Lake States: an economic analysis.

Treesearch

Jeffrey T. Olson; Allen L. Lundgren

1978-01-01

The 1968 Wisconsin Forest Survey showed large areas of aspen type that are not considered fully stocked. The economic feasibility of converting partially-stocked stands to full stocking is examined, and a rule presented for determining when a partially-stocked stand should be harvested to maximize its present value.

Estimating merchantable volumes of second growth Douglas-fir stands from total cubic volume and associated stand characteristics.

Treesearch

Richard L. Williamson; Robert O. Curtis

1980-01-01

Equations are given for estimating merchantable volumes of second-growth Douglas-fir stands to specified breast-high and top-diameter limits, in cubic feet or board feet, from total volume in cubic feet and certain associated stand characteristics.

Comparison of 70 deg tilt, LBNP, and passive standing as measures of orthostatic tolerance

NASA Technical Reports Server (NTRS)

Hyatt, K. H.; Jacobson, L. B.; Schneider, V. S.

1975-01-01

The present study was performed to assess the reliability of lower body negative pressure (LBNP) as a test of orthostatic tolerance. The need for this assessment arose from the prior observation in this laboratory that some subjects show wide day-to-day variation in heart rate responses to LBNP. The extent of these variations was so great as to raise a serious question as to the value of LBNP as a measure of study-induced alterations (e.g., those produced by bedrest or weightlessness) in orthostatic tolerance. Five healthy volunteers were subjected to a series of tests, consisting of 70 deg tilt, LBNP, and passive standing, on three occasions preceding and three occasions following a 2-week period of bedrest. Study results show that it is possible to subdivide the volunteers into subgroups which show either great or little day-to-day variability in any of the three tests. All three tests revealed bedrest-induced alterations in orthostatic tolerance quite adequately. Of the three tests studied, LBNP most frequently resulted in the largest test-induced heart rate alterations, followed by quiet standing and, finally 70 deg tilt.

Stand-age profile of North Carolina's timberland

Treesearch

Herbert A. Knight

1977-01-01

Most timber stands in North Carolina are even aged and appeared after some act of nature or man. The most common acts which lead to the establishment of a new stand are timber harvesting, retirement of farmland, wildfire, wind and ice storms, or insect and disease outbreaks. Most frequently, the new stand is a product of nature’s healing process. Less often, some land...