On the relationship factor between the PV module temperature and the solar radiation on it for various BIPV configurations

NASA Astrophysics Data System (ADS)

Kaplanis, S.; Kaplani, E.

2014-10-01

Temperatures of c-Si, pc-Si and a-Si PV modules making part of a roof in a building or hanging outside windows with various inclinations were measured with respect to the Intensity of the solar radiation on them under various environmental conditions. A relationship coefficient f was provided whose values are compared to those from a PV array operating in a free standing mode on a terrace. A theoretical model to predict f was elaborated. According to the analysis, the coefficient f takes higher values for PV modules embedded on a roof compared to the free standing PV array. The wind effect is much stronger for the free standing PV than for any BIPV configuration, either the PV is part of the roof, or placed upon the roof, or is placed outside a window like a shadow hanger. The f coefficient depends on various parameters such as angle of inclination, wind speed and direction, as well as solar radiation. For very low wind speeds the effect of the angle of inclination, β, of the PV module with respect to the horizontal on PV temperature is clear. As the wind speed increases, the heat transfer from the PV module shifts from natural flow to forced flow and this effect vanishes. The coefficient f values range from almost 0.01 m2°C/W for free standing PV arrays at strong wind speeds, vW>7m/s, up to around 0.05 m2°C/W for the case of flexible PV modules which make part of the roof in a BIPV system.

Estimating yellow-poplar growth and yield

Treesearch

Donald E. Beck

1989-01-01

Yellow-poplar grows in essentially pure, even-aged stands, so you can make growth and yield estimates from relatively few stand characteristics. The tables and models described here require only measures of stand age, stand basal area in trees 4.5 inches and larger, and site index. They were developed by remeasuring (at 5-year intervals over a 20-year period) many...

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

Three scales of aerial photography compared for making stand measurements

Treesearch

Earl J. Rogers; Gene Avery; Roy A. Chapman

1959-01-01

Three scales of aerial photography were tested in an attempt to determine the best scale to use in forest surveying. This was done by comparing photo measurements of average tree height, average crown diameter, and crown-closure percent. These stand variables were selected for testing because of their applicability in making aerial estimates of timber volume.

A Decision-Making Model For Managing or Regenerating Southern Upland Hardwoods

Treesearch

K. Kyle Cunningham; Andrew W. Ezell; Keith L. Belli; John D. Hodges

2004-01-01

A decision-making model for managing or regenerating southern upland hardwoods is being created for three physiographic provinces including the Cumberland Plateau, Western Highland Rim, and Upper Coastal Plain. The model performs a stand evaluation, from a silvicultural standpoint, and declares a stand as being either manageable or in need of regeneration. Model...

Proceedings: guidelines for regenerating Appalachian hardwood stands

Treesearch

H. Clay Smith; Arlyn W. Perkey; William E. Kidd

1988-01-01

This proceedings will provide field foresters and landowners with an update of current available information for regenerating Appalachian hardwood stands. We wanted a "state-of-the-art" proceedings for regenerating Appalachian hardwood stands. We asked the authors to make recommendations based on the current literature, their knowledge, and experience. Though...

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...

A SPATIAL ANALYSIS OF THE FINE ROOT BIOMASS FROM STAND DATA IN THE PACIFIC NORTHWEST

EPA Science Inventory

High spatial variability of fine roots in natural forest stands makes accurate estimates of stand-level fine root biomass difficult and expensive to obtain by standard coring methods. This study uses aboveground tree metrics and spatial relationships to improve core-based estima...

Optimum stand prescriptions for ponderosa pine

Treesearch

David W. Hann; J. Douglas Brodie; Kurt H. Riitters

1983-01-01

Two examples for a northern Arizona ponderosa pine stand illustrate the usefulness of dynamic programming in making silvicultural decisions. The first example analyzes the optimal planting density for bare land, while the second examines the optimal precommercial thinning intensity for a 43-year-old stand. Bot hexamples assume that the manager's primary objective...

Gibberellin Signaling: a Wake-up Call for Seed Germination

USDA-ARS?s Scientific Manuscript database

Making an appropriate decision to germinate is essential for the survival of plant species and is important for proper stand establishment in crop plants. Germination is regulated by the antagonistic effects to two plant hormones in Arabidopsis thaliana: abscisic acid (ABA) induces dormancy and repr...

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.

Optimized design for sling of stand up lift

NASA Astrophysics Data System (ADS)

Xu, Dongfang; Wang, Yue; Cui, Tengfei; Bao, Xuelian; Duan, Xingguang

2017-04-01

Stand up lift is a kind of equipment that assists those with dyskinesia of legs to stand up or move. As an important part of stand up lift, sling concerns the realization of the equipment's function and the safety of users. On the basis of ergonomics theory, this thesis will design and optimize the sling to make it safer and more comfortable and meet demands of different people.

Growth and Photosynthesis Characteristics of an Artificially Regenerated Mixed Hardwood Stand in the Southern USA

Treesearch

Shi-Jean S. Sung; Paul P. Kormanik; Stanley J. Zarnoch; Charles Possee

2002-01-01

The hardwood forests of the southern U.S. are not naturally composed of singe predominant species. The diversity of tree species within these stands is one of the qualities that make them so valuable for multiple use stand management. While many of the best hardwood sites have been planted to pines since the 1950's, some proportion of these pine stands now being...

Learning about Lasers

ERIC Educational Resources Information Center

Roberts, Larry

2011-01-01

The word laser is an acronym. It stands for Light Amplification by Stimulated Emission of Radiation. Lasers, invented in 1958, are used to cut and fuse materials, accurately survey long distances, communicate across fiber-optic phone lines, produce 3D pictures, make special effects, help navigation, and read bar codes for cash registers. A laser…

Back-pressure Effect on Shock-Train Location in a Scramjet Engine Isolator

DTIC Science & Technology

2010-03-01

valves .......................................................................................... 57 Side project: making an actuator stand...21 Figure 8. Main manual shut off valve ...................................................................................22 Figure 9 . A small...characteristic about this wind tunnel. With Mach 1.8 nozzle, prior to test runs, the upstream regulator pressure valve (Figure 9 ) was set at

[Comparison of three stand-level biomass estimation methods].

PubMed

Dong, Li Hu; Li, Feng Ri

2016-12-01

At present, the forest biomass methods of regional scale attract most of attention of the researchers, and developing the stand-level biomass model is popular. Based on the forestry inventory data of larch plantation (Larix olgensis) in Jilin Province, we used non-linear seemly unrelated regression (NSUR) to estimate the parameters in two additive system of stand-level biomass equations, i.e., stand-level biomass equations including the stand variables and stand biomass equations including the biomass expansion factor (i.e., Model system 1 and Model system 2), listed the constant biomass expansion factor for larch plantation and compared the prediction accuracy of three stand-level biomass estimation methods. The results indicated that for two additive system of biomass equations, the adjusted coefficient of determination (R a 2 ) of the total and stem equations was more than 0.95, the root mean squared error (RMSE), the mean prediction error (MPE) and the mean absolute error (MAE) were smaller. The branch and foliage biomass equations were worse than total and stem biomass equations, and the adjusted coefficient of determination (R a 2 ) was less than 0.95. The prediction accuracy of a constant biomass expansion factor was relatively lower than the prediction accuracy of Model system 1 and Model system 2. Overall, although stand-level biomass equation including the biomass expansion factor belonged to the volume-derived biomass estimation method, and was different from the stand biomass equations including stand variables in essence, but the obtained prediction accuracy of the two methods was similar. The constant biomass expansion factor had the lower prediction accuracy, and was inappropriate. In addition, in order to make the model parameter estimation more effective, the established stand-level biomass equations should consider the additivity in a system of all tree component biomass and total biomass equations.

Relationships between acoustic variables and different measures of stiffness in standing Pinus taeda trees

Treesearch

Christian R. Mora; Laurence R. Schimleck; Fikret Isik; Jerry M. Mahon Jr.; Alexander Clark III; Richard F. Daniels

2009-01-01

Acoustic tools are increasingly used to estimate standing-tree (dynamic) stiffness; however, such techniques overestimate static stiffness, the standard measurement for determining modulus of elasticity (MOE) of wood. This study aimed to identify correction methods for standing-tree estimates making dynamic and static stiffness comparable. Sixty Pinus taeda L...

Two commercial thinnings in century-old Douglas-fir.

Treesearch

Robert W. Steele

1954-01-01

As young-growth forests replace old-growth forests as the primary source of Douglas-fir raw material, the technique of managing young stands becomes increasingly important. Managers of young-growth timber need to know whether it is economical and silviculturally feasible to make thinnings in stands that are close to rotation age. Final harvest of some stands of this...

Validation of FIBER 3.0 for tolerant hardwood stands in Ontario

Treesearch

Jacek Bankowski; Daniel C. Dey; Murray Woods; Jim Rice; Eric Boysen; Brian Batchelor; Roj Miller

1995-01-01

Growth and yield projections aid foresters in assessing timber management opportunities and in making management decisions. With these uses, questions arise about the reliability and limits of growth and yield simulators. Using long-term studies of hardwood stands in Ontario the growth simulator FIBER 3.0 has been tested. Short-term (5 years) projections of stand...

Raising Sociocultural Awareness through Contextual Analysis: Some Tools for Teachers

ERIC Educational Resources Information Center

McConachy, Troy

2009-01-01

Despite long-standing recognition of the importance of sociocultural context in meaning making, criticisms have been levelled at communicative language teaching (CLT) for failing to effectively address this at the level of classroom practice. In fact, it has been argued that the way CLT presents content reveals a fundamentally reductionist view of…

Evaluating elk habitat interactions with GPS collars

Treesearch

Mark A. Rumble; Lakhdar Benkobi; Fredrick Lindzey; R. Scott Gamo

2001-01-01

Global positioning systems (GPS) are likely to revolutionize animal telemetry studies. GPS collars allow biologists to collect systematically scheduled data when VHF telemetry data is difficult or impossible to collect. Past studies have shown that the success of GPS telemetry is greater when animals are standing, or in open habitats. To make effective use of GPS...

Age and size effects on seed productivity of northern black spruce

Treesearch

J. N. Viglas; C. D. Brown; J. F. Johnstone

2013-01-01

Slow-growing conifers of the northern boreal forest may require several decades to reach reproductive maturity, making them vulnerable to increases in disturbance frequency. Here, we examine the relationship between stand age and seed productivity of black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) in Yukon Territory and Alaska....

Evidence-Based Practice: A Framework for Making Effective Decisions

ERIC Educational Resources Information Center

Spencer, Trina D.; Detrich, Ronnie; Slocum, Timothy A.

2012-01-01

The research to practice gap in education has been a long-standing concern. The enactment of No Child Left Behind brought increased emphasis on the value of using scientifically based instructional practices to improve educational outcomes. It also brought education into the broader evidence-based practice movement that started in medicine and has…

Different growth sensitivity to climate of the conifer Juniperus thurifera on both sides of the Mediterranean Sea

NASA Astrophysics Data System (ADS)

DeSoto, Lucía; Varino, Filipa; Andrade, José P.; Gouveia, Celia M.; Campelo, Filipe; Trigo, Ricardo M.; Nabais, Cristina

2014-12-01

Mediterranean plants cope with cold wet winters and dry hot summers, with a drought gradient from northwest to southeast. Limiting climatic conditions have become more pronounced in the last decades due to the warming trend and rainfall decrease. Juniperus thurifera L., a long-lived conifer tree endemic to the western Mediterranean region, has a disjunct distribution in Europe and Africa, making it a suitable species to study sensitivity to climate in both sides of the Mediterranean Basin. Tree-ring width chronologies were built for three J. thurifera stands at Spain (Europe) and three in Morocco (Africa) and correlated with monthly temperature and precipitation. The temporal stability of climate-growth relationships was assessed using moving correlations; the drought effect on growth was calculated using the monthly standardized precipitation-evapotranspiration index (SPEI) at different temporal scales. In the wettest stands, increasing spring temperature and summer precipitation enhanced growth, while in the driest stands, growth was enhanced by higher spring precipitation and lower summer temperature. The climate-growth correlations shifted during the twentieth century, especially since the 1970s. Particularly noticeable is the recent negative correlation with previous autumn and winter precipitation in the wettest stands of J. thurifera, probably related with an effect of cloud cover or flooding on carbon storage depletion for next year growth. The driest stands were affected by drought at long time scales, while the wettest stands respond to drought at short time scales. This reveals a different strategy to cope with drought conditions, with populations from drier sites able to cope with short periods of water deficit.

Acid or N? Disentangling Nutrient- and pH Effects of Nitrogen and Sulfur Deposition to Forest Ecosystems

NASA Astrophysics Data System (ADS)

Goodale, C. L.

2016-12-01

Nitrogen deposition can act as both a nutrient and acidifying agent with sometimes synergistic and sometimes contradictory effects on ecosystem processes. However, these two roles are rarely separated. Similarly, deposition patterns of N and S often covary, making it difficult to correctly attribute their respective roles on the biogeochemistry of downwind ecosystems. In 2011, we initiated a N x pH (S) experiment in six mixed hardwood stands (3 primary, 3 secondary) in Central New York designed to separate nutrient and acidifying impacts of N and S deposition. Three treatments included two 50 N ha-1 yr-1 additions in forms intended to raise (NaNO3) or lower ((NH4)2SO4) soil pH as well as elemental S treatment to acidify without N. Five years of treatment shifted surface soil pH in the expected directions. Treatment effects on soil extract DOC correlated with pH, with lower DOC concentration and aromaticity in the acidifying treatments. Foliar litterfall did not vary by stand age or treatment, but N and S treatments enriched litterfall N and S concentrations, respectively. Wood production did not vary significantly by stand age or treatment but trended toward an increase in response to the N additions in both stand ages. The treatments did not affect early stages of litter decomposition, but both N additions and acidification suppressed decomposition in later stages, with largest effects from acidification alone. Soil respiration responses followed those of litter decomposition, except that the response of respiration to the NaNO3 addition depended on the stand's mycorrhizal composition, with greater suppression in stands with a higher fraction of ectomycorrhizal tree species. Together, these results show that both N addition and acidification can suppress decomposition rates, but likely for different reasons that may be linked to plant carbon allocation (for N) and microbial function (pH). Distinguishing these mechanisms will be important for projecting recovery of ecosystem processes to changing N and S inputs.

Quasi-free-standing bilayer epitaxial graphene field-effect transistors on 4H-SiC (0001) substrates

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

Yu, C.; Li, J.; Song, X. B.

2016-01-04

Quasi-free-standing epitaxial graphene grown on wide band gap semiconductor SiC demonstrates high carrier mobility and good material uniformity, which make it promising for graphene-based electronic devices. In this work, quasi-free-standing bilayer epitaxial graphene is prepared and its transistors with gate lengths of 100 nm and 200 nm are fabricated and characterized. The 100 nm gate length graphene transistor shows improved DC and RF performances including a maximum current density I{sub ds} of 4.2 A/mm, and a peak transconductance g{sub m} of 2880 mS/mm. Intrinsic current-gain cutoff frequency f{sub T} of 407 GHz is obtained. The exciting DC and RF performances obtained in the quasi-free-standingmore » bilayer epitaxial graphene transistor show the great application potential of this material system.« less

Cordwood Yields From Thinnings in Young Oak Stands in the Missouri Ozarks

Treesearch

Kenneth W. Seidel

1966-01-01

Proposed construction in Missouri of pulpmills using oak cordwood should result in a greater demand for pole-size oak trees, thus making needed thinnings feasible in young oak stands. According to the 1958 forest survey, poletimber stands (which are mainly oak) occupy 39 percent of the commercial forest area of the eastern Ozakrs, more than any other size class. More...

Mortality and growth of dwarf mistletoe-infected red and white fir and the efficacy of thinning for reducing associated losses

Treesearch

H. K. Mehl; S. R. Mori; S. J. Frankel; D. M. Rizzo

2013-01-01

In managed forests dominated by true fir (Abies) species, stands are often restocked using understory trees retained during timber harvest, making the effects of dwarf mistletoe (Arceuthobium spp.) infestation on small true fir a concern. This study examined the response of small red (A. magnifica) and...

Smartphones and Other Mobile Devices: The Swiss Army Knives of the 21st Century

ERIC Educational Resources Information Center

Livingston, Alan

2004-01-01

MIAD stands for "mobile Internet access device." MIADs are the Swiss Army knives of the 21st century; they help users perform specific tasks in specific situations (including academic tasks in academic situations), thereby making users smarter and more productive. There are, however, significant obstacles to their effective use in higher…

A Comparison of Model-Based and Design-Based Impact Evaluations of Interventions in Developing Countries

ERIC Educational Resources Information Center

Hansen, Henrik; Klejnstrup, Ninja Ritter; Andersen, Ole Winckler

2013-01-01

There is a long-standing debate as to whether nonexperimental estimators of causal effects of social programs can overcome selection bias. Most existing reviews either are inconclusive or point to significant selection biases in nonexperimental studies. However, many of the reviews, the so-called "between-studies," do not make direct…

Making the Connection between Leisure and At-Risk Youth in Today's Society.

ERIC Educational Resources Information Center

Calloway, James

The sociology of leisure provides a rich and long-standing research tradition in deviant leisure activity. Leisure and recreation experiences are the product, not of a single system, but of the interaction among systems, none of which separately seems to effectively treat the family and its members. The need for recreational group activities is…

Simulation of L-band and HH microwave backscattering from coniferous forest stands - A comparison with SIR-B data

NASA Technical Reports Server (NTRS)

Sun, Guo-Qing; Simonett, David S.

1988-01-01

SIR-B images of the Mt. Shasta region of northern California are used to evaluate a composite L-band HH backscattering model of coniferous forest stands. It is found that both SIR-B and simulated backscattering coefficients for eight stands studied have similar trends and relations to average tree height and average number of trees per pixel. Also, the dispersion and distribution of simulated backscattering coefficients from each stand broadly match SIR-B data from the same stand. Although the limited quality and quantity of experimental data makes it difficult to draw any strong conclusions, the comparisons indicate that a stand-based L-band HH composite model seems promising for explaining backscattering features.

Effect of patient position on the lordosis and scoliosis of patients with degenerative lumbar scoliosis

PubMed Central

Fei, Han; Li, Wei-shi; Sun, Zhuo-ran; Jiang, Shuai; Chen, Zhong-qiang

2017-01-01

Abstract This study aimed to analyze the effect of patient positions on the lordosis and scoliosis of patients with degenerative lumbar scoliosis (DLS). Seventy-seven patients with DLS were retrospectively analyzed. We measured lordosis and Cobb's angle on preoperative upright x-rays and magnetic resonance imagings in supine position. The lordosis and scoliosis of surgical segments in intraoperative prone position were measured on intraoperative radiographs of 20 patients to compare with that in standing position. Paired t tests were performed to investigate the parameters of the sample. From standing to supine position the whole lordosis increased (29.2 ± 15.7 degree vs. 34.9 ± 11.2 degree), and the whole scoliosis decreased (24.3 ± 11.8 degree vs. 19.0 ± 10.5 degree); 53 of 77 (68.8%) cases had increased lordosis, and 67 of 77 (87%) cases had decreased scoliosis. The lordosis of surgical segments in standing position had no difference with that in intraoprerative prone position. But in changing from supine/standing position to intraoprerative prone position, the scoliosis of surgical segments decreased (14.7 ± 9.4 degree vs. 11.4 ± 7.0 degree; 19.0 ± 11.8 degree vs. 11.4 ± 7.0 degree, respectively), and 18 of 20 (90%) cases had decreased scoliosis in intraoperative prone position than that in standing position. Compared with standing position in DLS patients, supine position increased lordosis and reduced scoliosis, and intraoperative prone position reduced scoliosis significantly. When evaluating the severity of DLS and making preoperative surgical plans, lumbar lordosis in supine position should also be evaluated in addition to upright x-ray, and the effects of different positions should be taken into consideration to reduce deviation. PMID:28796046

Effect of patient position on the lordosis and scoliosis of patients with degenerative lumbar scoliosis.

PubMed

Fei, Han; Li, Wei-Shi; Sun, Zhuo-Ran; Jiang, Shuai; Chen, Zhong-Qiang

2017-08-01

This study aimed to analyze the effect of patient positions on the lordosis and scoliosis of patients with degenerative lumbar scoliosis (DLS).Seventy-seven patients with DLS were retrospectively analyzed. We measured lordosis and Cobb's angle on preoperative upright x-rays and magnetic resonance imagings in supine position. The lordosis and scoliosis of surgical segments in intraoperative prone position were measured on intraoperative radiographs of 20 patients to compare with that in standing position. Paired t tests were performed to investigate the parameters of the sample.From standing to supine position the whole lordosis increased (29.2 ± 15.7 degree vs. 34.9 ± 11.2 degree), and the whole scoliosis decreased (24.3 ± 11.8 degree vs. 19.0 ± 10.5 degree); 53 of 77 (68.8%) cases had increased lordosis, and 67 of 77 (87%) cases had decreased scoliosis. The lordosis of surgical segments in standing position had no difference with that in intraoprerative prone position. But in changing from supine/standing position to intraoprerative prone position, the scoliosis of surgical segments decreased (14.7 ± 9.4 degree vs. 11.4 ± 7.0 degree; 19.0 ± 11.8 degree vs. 11.4 ± 7.0 degree, respectively), and 18 of 20 (90%) cases had decreased scoliosis in intraoperative prone position than that in standing position.Compared with standing position in DLS patients, supine position increased lordosis and reduced scoliosis, and intraoperative prone position reduced scoliosis significantly. When evaluating the severity of DLS and making preoperative surgical plans, lumbar lordosis in supine position should also be evaluated in addition to upright x-ray, and the effects of different positions should be taken into consideration to reduce deviation.

The effect of selective tibial neurotomy and rehabilitation in a quadriplegic patient with ankle spasticity following traumatic brain injury.

PubMed

Jang, Sung Ho; Park, Sung-Min; Kim, Seong Ho; Ahn, Sang Ho; Cho, Yun Woo; Ahn, Mi Ok

2004-08-31

Ankle spasticity following brain injury leads to abnormal posture and joint contracture; making standing or walking impossible. This study investigates the efficacy of selective tibial neurotomy (STN) and intensive rehabilitation in a patient who suffered ankle spasticity after brain injury. This case describes a 37-year-old man whose traumatic brain injury (TBI) resulted in severe right ankle spasticity and contracture. He was unable to stand due to severe right ankle spasticity and contracture. Intensive rehabilitation and STN allowed him to walk without brace at 6 months and run at 12 months after STN. STN is an effective procedure to resolve localized spasticity of the ankle and it may be considered as a management strategy after local injection to alleviate ankle spasticity and/or contracture prior to orthopaedic surgery.

Total Participation Techniques: Making Every Student an Active Learner

ERIC Educational Resources Information Center

Himmele, Persida; Himmele, William

2011-01-01

Yes, there are easy-to-use and incredibly effective alternatives to the "stand and deliver" approach to teaching that causes so many students to tune out--or even drop out. Here's your opportunity to explore dozens of ways to engage K-12 students in active learning and allow them to demonstrate the depth of their knowledge and understanding. The…

Thinning southern bottomland hardwoods stands: Insect and disease consideratons

Treesearch

T. Evan Nebeker; Theodor D. Leininger; James S. Meadows; Michael D. Warriner

2005-01-01

The effects of thinning on insects and diseases have not been thoroughly examined in southern bottomland hardwood forests. To adress this issue, a study was initiated at sites in Mississippi and Alabama. These study sites allowed us to make observations concerning insect and disease activity 1-5 years following thinning. On all sites there was an unthinned control and...

Professional Learning in Canada: Learning Forward Releases a Landmark Study and Call to Action

ERIC Educational Resources Information Center

Learning Professional, 2017

2017-01-01

Learning Forward recently released findings from a new study that fills a long-standing gap in existing Pan-Canadian research, identifying key components of effective professional learning based on findings from educators' experiences in Canada. Accompanying the study is a call to action by Michael Fullan and Andy Hargreaves making the case for a…

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.

Arm motion coupling during locomotion-like actions: An experimental study and a dynamic model

PubMed Central

Shapkova, E.Yu; Terekhov, A.V.; Latash, M.L.

2010-01-01

We studied the coordination of arm movements in standing persons who performed an out-of-phase arm-swinging task while stepping in place or while standing. The subjects were instructed to stop one of the arms in response to an auditory signal while trying to keep the rest of the movement pattern unchanged. A significant increase was observed in the amplitude of the arm that continued swinging under both the stepping and standing conditions. This increase was similar between the right and left arms. A dynamic model was developed including two coupled non-linear van der Pol oscillators. We assumed that stopping an arm did not eliminate the coupling but introduced a new constraint. Within the model, superposition of two factors, a command to stop the ongoing movement of one arm and the coupling between the two oscillators, has been able to account for the observed effects. The model makes predictions for future experiments. PMID:21628725

Competency to stand trial and defendants who lack insight into their mental illness.

PubMed

Reisner, Andrew D; Piel, Jennifer; Makey, Miller

2013-01-01

Forensic evaluators often assess patients who lack insight into their mental illnesses. This lack of insight can have a significant impact on the defendant's ability to make legal strategy decisions that rely on their acceptance of their mental illness. In this article, the relationship between refusing an insanity plea and competency to stand trial will be explored in the context of defendants who lack insight into their mental illness. The authors argue that an adequate competency assessment should take into account the defendant's ability to consider his available pleas rationally. Such evaluations may have the effect of negating the necessity of a Frendak inquiry in those jurisdictions that can impose the insanity defense on defendants.

Construction alternatives for free-standing facilities.

PubMed

Brown, G

1990-01-01

Many hospitals are exploring free-standing facilities as an option for providing more efficient imaging services. Mr. Brown discusses the pros and cons of an emerging building technology, manufactured construction, in which building and site preparation are done simultaneously. He presents the criteria managers should use to make a knowledgeable decision.

Crown management and stand density

Treesearch

Thomas J. Dean; V. Clark Baldwin

1996-01-01

Determination of optimal stand-density continues to be a difficult problem. A trial cannot be established on every combination of soils, topography, and climate possible across the range of a widely distributed species such as loblolly pine, and continual advancements in nutrition and vegetation management, breeding, and utilization make established trials obsolete....

Strategy and Airpower

DTIC Science & Technology

2011-01-01

myopia often leads otherwise competent observers to under­ estimate significantly the new technology’s potential. Two business examples stand out: in...direction. With precision of effect combined with precision of impact, bloodless war becomes a reality . To this point, we have tried to make the...against virtually all of the centers of gravity directly related to strategic objectives, regardless of their loca­ tion. Because it can bring many

An Example of the Use of Research Methods and Findings as an Experiential Learning Exercise in an Accounting Theory Course

ERIC Educational Resources Information Center

Bublitz, Bruce; Philipich, Kirk; Blatz, Robert

2015-01-01

The purpose of this teaching note is to describe an experiential learning exercise used in a master's level financial accounting theory course. The experiential exercise illustrates how order effects can affect user's judgments, a long-standing research finding. This experiential exercise was used in an attempt to make students more cognizant of…

The Relationship between Item Context Characteristics and Student Performance: The Case of the 2006 and 2009 PISA Science Items

ERIC Educational Resources Information Center

Ruiz-Primo, Maria Araceli; Li, Min

2015-01-01

Background: A long-standing premise in test design is that contextualizing test items makes them concrete, less demanding, and more conducive to determining whether students can apply or transfer their knowledge. Purpose: We assert that despite decades of study and experience, much remains to be learned about how to construct effective and fair…

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

Spatial Interactions in Multiple-Use Forestry and Substitution and Wealth Effects for the Single Stand

Treesearch

Stephen K. Swallow; David N. Wear

1993-01-01

Forestry models often ignore spatial relationships between forest stands. This paper isolates the effects of stand interactions in muitiple-use forestry through a straightforward extension of the single-stand model. Effects of stand interactions decompose into wealth and substitution effects and may cause time-varying patterns of resource use for a forest...

The features of chlorophyll concentration long-standing dynamics in the ocean surface layer (comparison of czcs and seawifs data)

NASA Astrophysics Data System (ADS)

Shevyrnogov, A.; Vysotskaya, G.

To preserve biosphere and make its utilization expedient makes imperative to comprehend in depth long-standing dynamics of the primary production process on our planet. Variability of chlorophyll concentration in the ocean is one of the most important components of this process. However, hard access and large size of the water surface make its investigation labor-consuming. Besides, the dependence of primary production on high variability of hydrophysical phenomena in the ocean (fluctuations of currents, frontal zones, etc.) makes the location of points for measuring the chlorophyll concentration dynamics significant. In this work the long-standing changes in chlorophyll concentration in the surface layer of the ocean have been analyzed on the basis of the CZCS data for 7.5 years and the SeaWiFS data from 1997 to 2003. It was shown that the average chlorophyll concentration calculated at all investigated area is varied moderately. However when analyzing spatially local trends, it was detected that areas exist with stable rise and fall of chlorophyll concentration. Some interesting features of the long-standing dynamics of chlorophyll concentration several interesting features were found. There are the various directions of long-term trends (constant increase or decrease) that cannot be explained only by large-scale hydrological phenomena in the ocean (currents, upwellings etc.). The next feature is a difference between the trends revealed by using the CZCS data and the trends based on the SeaWiFS data. Thus, the obtained results allow the possibility of identification of the ocean biota role in the global biospheric gas exchange.

Assessing regeneration potential

Treesearch

Ivan L. Sander

1989-01-01

When a regeneration harvest cut is planned for even-aged stands or it is time to make another cut in uneven-aged stands, the first thing to do is assess the regeneration potential. Regeneration potential is the likelihood of being successful in reproducing desired species. You need an assessment to be reasonably sure that regeneration and management objectives can be...

Speed of Heart Rate Recovery in Response to Orthostatic Challenge.

PubMed

McCrory, Cathal; Berkman, Lisa F; Nolan, Hugh; O'Leary, Neil; Foley, Margaret; Kenny, Rose Anne

2016-08-19

Speed of heart rate recovery (HRR) may serve as an important biomarker of aging and mortality. To examine whether the speed of HRR after an orthostatic maneuver (ie, active stand from supine position) predicts mortality. A longitudinal cohort study involving a nationally representative sample of community-dwelling older individuals aged ≥50 years. A total of 4475 participants completed an active stand at baseline as part of a detailed clinic-based cardiovascular assessment. Beat-to-beat heart rate and blood pressure responses to standing were measured during a 2-minute window using a finometer and binned in 10-s intervals. We modeled HRR to the stand by age group, cardiovascular disease burden, and mortality status using a random effects model. Mortality status during a mean follow-up duration of 4.3 years served as the primary end point (n=138). Speed of HRR in the immediate 20 s after standing was a strong predictor of mortality. A 1-bpm slower HRR between 10 and 20 s after standing increased the hazard of mortality by 6% controlling for established risk factors. A clear dose-response relationship was evident. Sixty-nine participants in the slowest HRR quartile died during the observation period compared with 14 participants in the fastest HRR quartile. Participants in the slowest recovery quartile were 2.3× more likely to die compared with those in the fastest recovery quartile. Speed of orthostatic HRR predicts mortality and may aid clinical decision making. Attenuated orthostatic HRR may reflect dysregulation of the parasympathetic branch of the autonomic nervous system. © 2016 American Heart Association, Inc.

The impact of defendant ethnicity on the psycholegal opinions of forensic mental health evaluators.

PubMed

McCallum, Katherine E; MacLean, Nina; Neil Gowensmith, W

2015-01-01

The impact of ethnicity on clinicians' decision making has received a great deal of attention and research. Several studies have documented that client ethnicity significantly influences diagnoses, testing and assessment protocols, recommendations for treatment, and expected outcomes. However, there is limited research examining the impact of a criminal defendant's ethnicity upon forensic mental health experts. To examine this issue, the authors reviewed 816 forensic reports on competency to stand trial submitted to the Hawaii judiciary between 2007 and 2008 and compared recommendation rates across categories of defendant ethnicity. Significant differences between ethnic groups were found in recommendations of competency to stand trial. Specifically, Asian misdemeanant populations were found to be incompetent to stand trial at higher rates than other ethnic groups. These findings highlight the potential impact that ethnicity may have on clinicians' decision making in certain forensic settings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transpiration and water-use efficiency in mixed-species forests versus monocultures: effects of tree size, stand density and season.

PubMed

Forrester, David I

2015-03-01

Mixtures can be more productive than monocultures and may therefore use more water, which may make them more susceptible to droughts. The species interactions that influence growth, transpiration and water-use efficiency (WUE, tree growth per unit transpiration) within a given mixture vary with intra- and inter-annual climatic variability, stand density and tree size, but these effects remain poorly quantified. These relationships were examined in mixtures and monocultures of Eucalyptus globulus Labill. and Acacia mearnsii de Wildeman. Growth and transpiration were measured between ages 14 and 15 years. All E. globulus trees in mixture that were growing faster than similar sized trees in monocultures had higher WUE, while trees with similar growth rates had similar WUE. By the age of 14 years A. mearnsii trees were beginning to senesce and there were no longer any relationships between tree size and growth or WUE. The relationship between transpiration and tree size did not differ between treatments for either species, so stand-level increases in transpiration simply reflected the larger mean tree size in mixtures. Increasing neighbourhood basal area increased the complementarity effect on E. globulus growth and transpiration. The complementarity effect also varied throughout the year, but this was not related to the climatic seasonality. This study shows that stand-level responses can be the net effect of a much wider range of individual tree-level responses, but at both levels, if growth has not increased for a given species, it appears unlikely that there will be differences in transpiration or WUE for that species. Growth data may provide a useful initial indication of whether mixtures have higher transpiration or WUE, and which species and tree sizes contribute to this effect. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Standing Wave on a String as an Oscillator

ERIC Educational Resources Information Center

Sobel, Michael

2007-01-01

In the usual treatment of waves in introductory courses, one begins with traveling waves and the frequency/wavelength relationship f[lambda] = v, where "v" is the wave velocity. One then makes the point about superposition and shows that two waves traveling in opposite directions can add up to a standing wave; Eq. (1) still applies. This approach…

Forest stand structure of the northern spotted owl's foraging habitat.

Treesearch

Malcolm P. North; Jerry F. Franklin; Andrew B. Carey; Eric D. Forsman; Tom Hamer

1999-01-01

Although the spotted owl's close association with old growth has been extensively studied, it more difficult to identify and quantify the abundance of particular stand structures associated with preferred owl foraging sites. Old-growth forests have a suite of characteristics that distinguish them from younger forests but which also make it difficult to isolate...

Melde's experiment with an aquarium aerator. Rich dynamics with inexpensive apparatus

NASA Astrophysics Data System (ADS)

Graham, Mark

1998-05-01

As the basis for understanding music, quantum mechanics, and optical phenomena, standing waves are tremendously important, but instructors with a shoestring budget may not be able to do laboratories for them. However with simple modification of an inexpensive aquarium aerator costing a few dollars, instructors can take that shoestring and make standing waves.

Modeling individual tree survial

Treesearch

Quang V. Cao

2016-01-01

Information provided by growth and yield models is the basis for forest managers to make decisions on how to manage their forests. Among different types of growth models, whole-stand models offer predictions at stand level, whereas individual-tree models give detailed information at tree level. The well-known logistic regression is commonly used to predict tree...

Experience with basal area estimation by prisms in lodgepole pine.

Treesearch

James M. Trappe

1957-01-01

Estimation of basal area by prisms offers intriguing possibilities for reducing time and effort in making stand inventories. Increased inventory efficiency is a particular need in stands that are relatively low in value due to small stems, predominance of low value species or heavy defect. In the Pacific Northwest, lodgepole pine characteristically forms dense low-...

Selecting a silvicultural system

Treesearch

Richard M. Godman

1992-01-01

Sometimes a name creates a problem. The name of a silvicultural system usually refers to the way a stand is cut to get regeneration-"single tree selection"-for example. Trouble is, the name suggests that the regeneration cut will be the first treatment applied to the stand. Not so. We are now mostly making "intermediate" cuts in our Lake States...

The carbon consequences of thinning techniques: stand structure makes a difference

Treesearch

Coeli Hoover; Susan Stout

2007-01-01

Using results from a 25-year study of thinning in a northwestern Pennsylvania Allegheny hardwood stand, we assess whether and how thinning method affected carbon sequestration and merchantable volume production. Plots were thinned to similar residual relative density by removing trees from different portions of the diameter distribution. Plots that were thinned from...

Economic considerations of uneven-age hardwood management

Treesearch

H. Clay Smith; Gary W. Miller

1987-01-01

Uneven-age management or partial cutting methods as described in this paper allow foresters to manage eastern hardwood stands and harvest forest products without clearcutting. These methods can involve regular periodic harvests, at least for the short term, based on stand conditions and growing-site capabilities. We are not going to make the decision as to which is the...

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

Trubilko, A. I., E-mail: trubilko.andrey@gmail.com

Coherent scattering of a two-level atom in the field of a quantized standing wave of a micromaser is considered under conditions of initial quantum correlation between the atom and the field. Such a correlation can be produced by a broadband parametric source. The interaction leading to scattering of the atom from the nonuniform field occurs in the dispersion limit or in the wing of the absorption line of the atom. Apart from the quantized field, the atom simultaneously interacts with two classical counterpropagating waves with different frequencies, which are acting in the plane perpendicular to the atom’s propagation velocity andmore » to the wavevector of the standing wave. Joint action of the quantized field and two classical waves induces effective two-photon and Raman resonance interaction on the working transition. The effective Hamiltonian of the interaction is derived using the unitary transformation method developed for a moving atom. A strong effect is detected, which makes it possible to distinguish the correlated initial state of the atom and the field in the scattering of atom from the state of independent systems. For all three waves, scattering is not observed when systems with quantum correlation are prepared using a high-intensity parametric source. Conversely, when the atom interacts only with the nonuniform field of the standing wave, scattering is not observed in the case of the initial factorized state.« less

Stand structural diversity rather than species diversity enhances aboveground carbon storage in secondary subtropical forests in Eastern China

NASA Astrophysics Data System (ADS)

Ali, Arshad; Yan, En-Rong; Chen, Han Y. H.; Chang, Scott X.; Zhao, Yan-Tao; Yang, Xiao-Dong; Xu, Ming-Shan

2016-08-01

Stand structural diversity, typically characterized by variances in tree diameter at breast height (DBH) and total height, plays a critical role in influencing aboveground carbon (C) storage. However, few studies have considered the multivariate relationships of aboveground C storage with stand age, stand structural diversity, and species diversity in natural forests. In this study, aboveground C storage, stand age, tree species, DBH and height diversity indices, were determined across 80 subtropical forest plots in Eastern China. We employed structural equation modelling (SEM) to test for the direct and indirect effects of stand structural diversity, species diversity, and stand age on aboveground C storage. The three final SEMs with different directions for the path between species diversity and stand structural diversity had a similar goodness of fit to the data. They accounted for 82 % of the variation in aboveground C storage, 55-59 % of the variation in stand structural diversity, and 0.1 to 9 % of the variation in species diversity. Stand age demonstrated strong positive total effects, including a positive direct effect (β = 0.41), and a positive indirect effect via stand structural diversity (β = 0.41) on aboveground C storage. Stand structural diversity had a positive direct effect on aboveground C storage (β = 0.56), whereas there was little total effect of species diversity as it had a negative direct association with, but had a positive indirect effect, via stand structural diversity, on aboveground C storage. The negligible total effect of species diversity on aboveground C storage in the forests under study may have been attributable to competitive exclusion with high aboveground biomass, or a historical logging preference for productive species. Our analyses suggested that stand structural diversity was a major determinant for variations in aboveground C storage in the secondary subtropical forests in Eastern China. Hence, maintaining tree DBH and height diversity through silvicultural operations might constitute an effective approach for enhancing aboveground C storage in these forests.

Climate policy to defeat the green paradox.

PubMed

Fölster, Stefan; Nyström, Johan

2010-05-01

Carbon dioxide emissions have accelerated since the signing of the Kyoto Protocol. This discouraging development may partly be blamed on accelerating world growth and on lags in policy instruments. However, it also raises serious question concerning whether policies to reduce CO2 emissions are as effective as generally assumed. In recent years, a considerable number of studies have identified various feedback mechanisms of climate policies that often erode, and occasionally reinforce, their effectiveness. These studies generally focus on a few feedback mechanisms at a time, without capturing the entire effect. Partial accounting of policy feedbacks is common in many climate scenarios. The IPCC, for example, only accounts for direct leakage and rebound effects. This article attempts to map the aggregate effects of different types of climate policy feedback mechanisms in a cohesive framework. Controlling feedback effects is essential if the policy measures are to make any difference on a global level. A general conclusion is that aggregate policy feedback mechanisms tend to make current climate policies much less effective than is generally assumed. In fact, various policy measures involve a definite risk of 'backfiring' and actually increasing CO2 emissions. This risk is particularly pronounced once effects of climate policies on the pace of innovation in climate technology are considered. To stand any chance of controlling carbon emissions, it is imperative that feedback mechanisms are integrated into emission scenarios, targets for emission reduction and implementation of climate policy. In many cases, this will reduce the scope for subsidies to renewable energy sources, but increase the scope for other measures such as schemes to return carbon dioxide to the ground and to mitigate emissions of greenhouse gases from wetlands and oceans. A framework that incorporates policy feedback effects necessitates rethinking the design of the national and regional emission targets. This leads us to a new way of formulating emission targets that include feedback effects, the global impact target. Once the full climate policy feedback mechanisms are accounted for, there are probably only three main routes in climate policy that stand a chance of mitigating global warming: (a) returning carbon to the ground, (b) technological leaps in zero-emission energy technology that make it profitable to leave much carbon in the ground even in Annex II countries and (c) international agreements that make it more profitable to leave carbon in the ground or in forests.

Planned Experiments on the Princeton Advanced Test Stand

NASA Astrophysics Data System (ADS)

Stepanov, A.; Gilson, E. P.; Grisham, L.; Kaganovich, I.; Davidson, R. C.

2010-11-01

The Princeton Advanced Test Stand (PATS) device is an experimental facility based on the STS-100 high voltage test stand transferred from LBNL. It consists of a multicusp RF ion source, a pulsed extraction system capable of forming high-perveance 100keV ion beams, and a large six-foot-long vacuum with convenient access for beam diagnostics. This results in a flexible system for studying high perveance ion beams relevant to NDCX-I/II, including experiments on beam neutralization by ferroelectric plasma sources (FEPS) being developed at PPPL. Research on PATS will concern the basic physics of beam-plasma interactions, such as the effects of volume neutralization on beam emittance, as well as optimizing technology of the FEPS. PATS combines the advantage of an ion beam source and a large-volume plasma source in a chamber with ample access for diagnostics, resulting in a robust setup for investigating and improving relevant aspects of neutralized drift. There are also plans for running the ion source with strongly electro-negative gases such as chlorine, making it possible to extract positive or negative ion beams.

Biology, ecology, and economics at play: land use and land cover changes in the 21st century.

Treesearch

Sally Duncan

2003-01-01

In making choices about how to manage the country’s wealth of forest land, stakeholders including U.S. taxpayers—have many choices, all of them with ripple effects that extend far beyond the immediate stands of trees. In the Pacific Northwest, as elsewhere, biophysical, ecological, and socioeconomic factors combine to influence the areas of forest cover types and their...

Disproportionation for growing copper nanowires and their controlled self-assembly facilitated by ligand exchange.

PubMed

Ye, Enyi; Zhang, Shuang-Yuan; Liu, Shuhua; Han, Ming-Yong

2011-03-07

The coating makes the wire bundle: High-quality free-standing copper nanowires have been successfully produced by disproportionation of Cu(+) in oleylamine. This provides an effective way to prepare high-quality copper nanowires, but also enriches synthetic routes to other nanostructures. These copper nanowires can self-assemble by surface ligand exchange of oleylamine with trioctylphosphine. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Forest fragmentation and Red-cockaded Woodpecker population: an analysis at intermediate scale

Treesearch

D. Craig Rudolph; Richard N. Conner

1994-01-01

The Red-cockaded Woodpecker population on the Sam Houston National Forest in Texas was surveyed during 1988. The 128 active clusters present make this population one of the largest in existence. Pine stand ages varied considerably across the forest. Correlation analysis indicated that stand area in excess of 60 yr of age is positively correlated with measures of...

Stand-yield prediction for managed Ocala sand pine

Treesearch

D.L. Rockwood; B. Yang; K.W. Outcalt

1997-01-01

Sand pine is a very important species in Florida, producing significant quantities of fiber. The purpose of this study was to develop the site index and stand-level growth and yield equations managers need to make informed decisions. Data were collected from 35 seeded plots of Ocala sand pine covering a range of site indexes, ages, and densities in 1982-83. These plots...

America: The Trillion Dollar Lemonade Stand. Fundamentals of Free Enterprise, No. 1. Revised.

ERIC Educational Resources Information Center

American Fletcher National Bank and Trust Co., Indianapolis, IN.

Designed for high school economics students as a public service project of the American Fletcher National Bank, the booklet examines the American free enterprise system as it relates to the traditional lemonade stand and its ability to make a profit. The parallel is made by considering some basic principles: (1) the constant need for capital to…

Reproduction cutting methods for naturally regenerated pine stands in the south

Treesearch

James M. Guldin

2004-01-01

It is projected that plantations will make up 25 percent of the South's forest land area by the year 2040. Thus the remaining 75 percent of that area will consist of naturally regenerated pine, pine-hardwood, and hardwood stands. Naturally regenerated pines can be managed successfully by even-aged and unevenaged silvicultural systems when the reproduction cutting...

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...

Free-Standing, Flexible, Superomniphobic Films.

PubMed

Vahabi, Hamed; Wang, Wei; Movafaghi, Sanli; Kota, Arun K

2016-08-31

Fabrication of most superomniphobic surfaces requires complex process conditions or specialized and expensive equipment or skilled personnel. In order to circumvent these issues and make them end-user-friendly, we developed the free-standing, flexible, superomniphobic films. These films can be stored and delivered to the end-users, who can readily attach them to virtually any surface (even irregular shapes) and impart superomniphobicity. The hierarchical structure, the re-entrant texture, and the low solid surface energy render our films superomniphobic for a wide variety of liquids. We demonstrate that our free-standing, flexible, superomniphobic films have applications in enhanced chemical resistance and enhanced weight bearing.

Enhanced graphene oxide membranes and methods for making same

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

Shin, Yongsoon; Gotthold, David W.; Fifield, Leonard S.

A method for making a graphene oxide membrane and a resulting free-standing graphene oxide membrane that provides desired qualities of water permeability and selectivity at larger sizes, thinner cross sections, and with increased ruggedness as compared to existing membranes and processes.

NREL Pioneers Better Way to Make Renewable Hydrogen | News | NREL

Science.gov Websites

Pioneers Better Way to Make Renewable Hydrogen News Release: NREL Pioneers Better Way to Make Renewable Hydrogen January 9, 2017 A man stands outside on the grounds of the NREL campus. John Turner is a research fellow at the National Renewable Energy Laboratory, where he has worked since 1979. Credit: Dennis

An assessment of residual stand conditions following shelterwood-with-reserves cuts in Appalachian hardwoods

Treesearch

James E. Johnson; Gary W. Miller; John E. Baumgras; Cynthia D. West

1999-01-01

In recent years foresters managing hardwoods in the Southern Appalachians have been investigating a variety of regeneration methods that lead to the development of a two-aged stand. The reserved trees that make up the older age class usually meet a variety of objectives such as timber, wildlife food and cover, and aesthetic values. A series of 20 operational cuts in...

Stand-replacing patches within a ‘mixed severity’ fire regime: quantitative characterization using recent fires in a long-established natural fire area

Treesearch

B.M. Collins; S.L. Stephens

2010-01-01

The complexity inherent in variable, or mixed-severity fire regimes makes quantitative characterization of important fire regime attributes (e.g., proportion of landscape burned at different severities, size and distribution of stand-replacing patches) difficult. As a result, there is ambiguity associated with the term ‘mixed-severity’. We address...

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

Numerical study of laminar, standing hydraulic jumps in a planar geometry.

PubMed

Dasgupta, Ratul; Tomar, Gaurav; Govindarajan, Rama

2015-05-01

We solve the two-dimensional, planar Navier-Stokes equations to simulate a laminar, standing hydraulic jump using a Volume-of-Fluid method. The geometry downstream of the jump has been designed to be similar to experimental conditions by including a pit at the edge of the platform over which liquid film flows. We obtain jumps with and without separation. Increasing the inlet Froude number pushes the jump downstream and makes the slope of the jump weaker, consistent with experimental observations of circular jumps, and decreasing the Reynolds number brings the jump upstream while making it steeper. We study the effect of the length of the domain and that of a downstream obstacle on the structure and location of the jump. The transient flow which leads to a final steady jump is described for the first time to our knowledge. In the moderate Reynolds number regime, we obtain steady undular jumps with a separated bubble underneath the first few undulations. Interestingly, surface tension leads to shortening of wavelength of these undulations. We show that the undulations can be explained using the inviscid theory of Benjamin and Lighthill (Proc. R. Soc. London, Ser. A, 1954). We hope this new finding will motivate experimental verification.

Mistletoe, friend and foe: synthesizing ecosystem implications of mistletoe infection

NASA Astrophysics Data System (ADS)

Griebel, Anne; Watson, David; Pendall, Elise

2017-11-01

Biotic disturbances are affecting a wide range of tree species in all climates, and their occurrence is contributing to increasing rates of tree mortality globally. Mistletoe is a widespread group of parasitic plants that establishes long-lasting relationships with a diverse range of host tree species. With climate change, ecophysiological stress is increasing, potentially making trees more susceptible to mistletoe infection, which in turn leads to higher forest mortality rates. The perception of mistletoe presence in individual trees and forest stands is divided within the scientific community, leading to an ongoing debate regarding its impacts. Forest managers concerned about stand health and carbon sequestration may view mistletoe as a foe that leads to reduced productivity. In contrast, ecologists may see mistletoe as a friend, in light of the wildlife habitat, biodiversity and nutrient cycling it promotes. However, individual studies typically focus on isolated effects of mistletoe presence within their respective research area and lack a balanced, interdisciplinary perspective of mistletoe disturbance. With this conceptual paper we aim to bring together the positive and negative impacts of mistletoe presence on tree physiology, soil nutrient cycling as well as stand health and stand dynamics. We focus on the role of mistletoe-induced tree mortality in ecosystem succession and biodiversity. In addition, we present potential modifications of mistletoe presence on the energy budget and on forest vulnerability to climate change, which could feed back into stand dynamics and disturbance patterns. Lastly, we will identify the most pressing remaining knowledge gaps and highlight priorities for future research on this widespread agent of biotic disturbance.

The automatic control system and stand-by facilities of the TDMA-40 equipment

NASA Astrophysics Data System (ADS)

Gudenko, D. V.; Pankov, G. Kh.; Pauk, A. G.; Tsirlin, V. M.

1980-10-01

When a controlling station in a satellite communications system is out of order, a complex algorithm must be carried out for automatic operation of the stand-by equipment. A processor has been developed to perform this algorithm, as well as operations involving the stand-by facilities of the receiving-transmitting equipment of the station. The design principles and solutions to problems in developing the equipment for the monitoring and controlling systems are described. These systems are based on multistation access using time division multiplexing. Algorithms are presented for the operation of the synchronizing processor and the control processor of the equipment. The automatic control system and stand-by facilities make it possible to reduce the service personnel and to design an unattended station.

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.

Organization and Leadership in Hospitals

NASA Astrophysics Data System (ADS)

Taylor, James H.

Good Morning. I was surprised yesterday morning after listening to Karl Weick's wonderful presentation to find myself thinking that I should be telling a story, rather than making an attempt to give an academic lecture. I am not an academic and most of the communicating I do is, in essence, story telling. Listening to Dr. Weick, I was struck by how effective his narrative was in making his points. If an outstanding scholar can stand before so many accomplished academics and tell a story, I decided that it would be all right for this practitioner to do so also. So I left the disk with my PowerPoint presentation in my room. I hope you will find my story interesting.

[Silvicultural treatments and their selection effects].

PubMed

Vincent, G

1973-01-01

Selection can be defined in terms of its observable consequences as the non random differential reproduction of genotypes (Lerner 1958). In the forest stands we are selecting during the improvements-fellings and reproduction treatments the individuals surpassing in growth or in production of first-class timber. However the silvicultural treatments taken in forest stands guarantee a permanent increase of forest production only in such cases, if they have been taken with respect to the principles of directional (dynamic) selection. These principles require that the trees determined for further growing and for forest regeneration are selected by their hereditary properties, i.e. by their genotypes.For making this selection feasible, our study deals with the genetic parameters and gives some examples of the application of the response, the selection differential, the heritability in the narrow and in the broad sense, as well as of the genetic and genotypic gain. On the strength of this parameter we have the possibility to estimate the economic success of several silvicultural treatments in forest stands.The mentioned examples demonstrate that the selection measures of a higher intensity will be manifested in a higher selection differential, in a higher genetic and genotypic gain and that the mentioned measures show more distinct effects in the variable populations - in natural forest - than in the population characteristic by a smaller variability, e.g. in many uniform artificially established stands.The examples of influences of different selection on the genotypes composition of population prove that genetics instructs us to differentiate the different genotypes of the same species and gives us at the same time a new criterions for evaluating selectional treatments. These criterions from economic point of view is necessary to consider in silviculture as advantageous even for the reason that we can judge from these criterions the genetical composition of forest stands in the following generation, it means, within the scope of time for more than a human age.

Effects of Mountain Pine Beetle on Fuels and Expected Fire Behavior in Lodgepole Pine Forests, Colorado, USA

PubMed Central

Schoennagel, Tania; Veblen, Thomas T.; Negron, José F.; Smith, Jeremy M.

2012-01-01

In Colorado and southern Wyoming, mountain pine beetle (MPB) has affected over 1.6 million ha of predominantly lodgepole pine forests, raising concerns about effects of MPB-caused mortality on subsequent wildfire risk and behavior. Using empirical data we modeled potential fire behavior across a gradient of wind speeds and moisture scenarios in Green stands compared three stages since MPB attack (Red [1–3 yrs], Grey [4–10 yrs], and Old-MPB [∼30 yrs]). MPB killed 50% of the trees and 70% of the basal area in Red and Grey stages. Across moisture scenarios, canopy fuel moisture was one-third lower in Red and Grey stages compared to the Green stage, making active crown fire possible at lower wind speeds and less extreme moisture conditions. More-open canopies and high loads of large surface fuels due to treefall in Grey and Old-MPB stages significantly increased surface fireline intensities, facilitating active crown fire at lower wind speeds (>30–55 km/hr) across all moisture scenarios. Not accounting for low foliar moistures in Red and Grey stages, and large surface fuels in Grey and Old-MPB stages, underestimates the occurrence of active crown fire. Under extreme burning conditions, minimum wind speeds for active crown fire were 25–35 km/hr lower for Red, Grey and Old-MPB stands compared to Green. However, if transition to crown fire occurs (outside the stand, or within the stand via ladder fuels or wind gusts >65 km/hr), active crown fire would be sustained at similar wind speeds, suggesting observed fire behavior may not be qualitatively different among MPB stages under extreme burning conditions. Overall, the risk (probability) of active crown fire appears elevated in MPB-affected stands, but the predominant fire hazard (crown fire) is similar across MPB stages and is characteristic of lodgepole pine forests where extremely dry, gusty weather conditions are key factors in determining fire behavior. PMID:22272268

Theoretical Antecedents of Standing at Work: An Experience Sampling Approach Using the Theory of Planned Behavior.

PubMed

Meyer, M Renée Umstattd; Wu, Cindy; Walsh, Shana M

2016-01-01

Time spent sitting has been associated with an increased risk of diabetes, cancer, obesity, and mental health impairments. However, 75% of Americans spend most of their days sitting, with work-sitting accounting for 63% of total daily sitting time. Little research examining theory-based antecedents of standing or sitting has been conducted. This lack of solid groundwork makes it difficult to design effective intervention strategies to decrease sitting behaviors. Using the Theory of Planned Behavior (TPB) as our theoretical lens to better understand factors related with beneficial standing behaviors already being practiced, we examined relationships between TPB constructs and time spent standing at work among "positive deviants" (those successful in behavior change). Experience sampling methodology (ESM), 4 times a day (midmorning, before lunch, afternoon, and before leaving work) for 5 consecutive workdays (Monday to Friday), was used to assess employees' standing time. TPB scales assessing attitude (α = 0.81-0.84), norms (α = 0.83), perceived behavioral control (α = 0.77), and intention (α = 0.78) were developed using recommended methods and collected once on the Friday before the ESM surveys started. ESM data are hierarchically nested, therefore we tested our hypotheses using multilevel structural equation modeling with Mplus. Hourly full-time university employees (n = 50; 70.6% female, 84.3% white, mean age = 44 (SD = 11), 88.2% in full-time staff positions) with sedentary occupation types (time at desk while working ≥6 hours/day) participated. A total of 871 daily surveys were completed. Only perceived behavioral control (β = 0.45, p < 0.05) was related with work-standing at the event-level (model fit: just fit); mediation through intention was not supported. This is the first study to examine theoretical antecedents of real-time work-standing in a naturalistic field setting among positive deviants. These relationships should be further examined, and behavioral intervention strategies should be guided by information obtained through this positive deviance approach to enhance perceived behavioral control, in addition to implementing environmental changes like installing standing desks.

Making the little things count: modeling the development of understory trees in complex stands

Treesearch

Peter J. Gould; Connie. Harrington

2013-01-01

Forest growth models are useful for asking “What if?” questions when evaluating silvicultural treatments intended to increase the complexity of future stands. What if we thinned to level A or B? How would it aff ect the growth rates of understory trees? How many trees would survive? To answer these types of questions, a growth model needs to...

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...

Effects of standing on typing task performance and upper limb discomfort, vascular and muscular indicators.

PubMed

Fedorowich, Larissa M; Côté, Julie N

2018-10-01

Standing is a popular alternative to traditionally seated computer work. However, no studies have described how standing impacts both upper body muscular and vascular outcomes during a computer typing task. Twenty healthy adults completed two 90-min simulated work sessions, seated or standing. Upper limb discomfort, electromyography (EMG) from eight upper body muscles, typing performance and neck/shoulder and forearm blood flow were collected. Results showed significantly less upper body discomfort and higher typing speed during standing. Lower Trapezius EMG amplitude was higher during standing, but this postural difference decreased with time (interaction effect), and its variability was 68% higher during standing compared to sitting. There were no effects on blood flow. Results suggest that standing computer work may engage shoulder girdle stabilizers while reducing discomfort and improving performance. Studies are needed to identify how standing affects more complex computer tasks over longer work bouts in symptomatic workers. Copyright © 2018 Elsevier Ltd. All rights reserved.

Making better use of the policies and funding we already have.

PubMed

Baxter, Raymond J

2010-09-01

The potential for population health reform could be enhanced by assessing whether we have made the most of policies and resources already available. Opportunities to promote population health independent of major changes in resources or public authority include the following: enforcing laws already in effect; clarifying and updating the application of long-standing policies; leveraging government's and the private sector's purchasing and investment clout; facilitating access to programs by everyone who is eligible for them; evaluating the effectiveness of population health programs, agencies, and policies; and intervening to stop agencies and policies from operating at cross-purposes.

'Consumers are patients!' shared decision-making and treatment non-compliance as business opportunity.

PubMed

Applbaum, Kalman

2009-03-01

This article describes an aspect of the progressive insertion of commercial interests into the relationship between patients and their clinicians, with particular reference to psychiatry. Treatment noncompliance, a long-standing problem for healthcare professionals, has lately drawn the attention of the pharmaceutical and allied industries as a site at which to improve return on investment (ROI). Newly founded corporate ;compliance departments' and specialized consultancies that regard noncompliance as a form of marketing failure are seeking to rectify it with reinvigorated models and strategies. This intervention stands to impact patients' experience of illness as well as the participation of those formally (physicians, case managers, etc.) and informally (family, friends, etc.) involved in treatment. My analysis draws upon observation at compliance conferences to demonstrate the contrasting models of patient empowerment underlying the marketing vs. medical approaches. I propose a research agenda for measuring the effects of industry compliance programs.

Effect of Power Exchange of India: An Overview and Key Issues

NASA Astrophysics Data System (ADS)

Singh, A.; Chauhan, D. S.; Upadhdhyay, K. G.

2013-09-01

There stands no guarantee that if potential market participants are simply provided with the opportunity for trading electricity, there shall be an efficient wholesale electricity market. India, as well as various other developed countries, relies on voluntary agreements as far as electricity trading is concerned. Self, private initiatives to standardize and commodities contracts play an important role in increasing the trading volume to improve efficiency, in developed countries. In accordance with their experiences, this paper suggested a specific strategy to promote bilateral/OTC trading; hence, India needed to develop a master agreement for electricity contracts. This paper discusses that the creating power exchange for short-term trading in the spot market materializing the contract for the convenience of market participants stands particularly important and henceforth is a necessary factor to make sure that spot market is workable and competitive prior to developing a financial contract for electricity trading.

Space/age forestry: Implications of planting density and rotation age in SRIC management decisions

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

Merriam, R.A.; Phillips, V.D.; Liu, W.

1993-12-31

Short-rotation intensive-culture (SRIC) of promising tree crops is being evaluated worldwide for the production of methanol, ethanol, and electricity from renewable biomass resources. Planting density and rotation age are fundamental management decisions associated with SRIC energy plantations. Most studies of these variables have been conducted without the benefit of a unifying theory of the effects of growing space and rotation age on individual tree growth and stand level productivity. A modeling procedure based on field trials of Eucalyptus spp. is presented that evaluates the growth potential of a tree in the absence and presence of competition of neighboring trees inmore » a stand. The results of this analysis are useful in clarifying economic implications of different growing space and rotation age decisions that tree plantation managers must make. The procedure is readily applicable to other species under consideration for SRIC plantations at any location.« less

Hybrid Photon-Plasmon Coupling and Ultrafast Control of Nanoantennas on a Silicon Photonic Chip.

PubMed

Chen, Bigeng; Bruck, Roman; Traviss, Daniel; Khokhar, Ali Z; Reynolds, Scott; Thomson, David J; Mashanovich, Goran Z; Reed, Graham T; Muskens, Otto L

2018-01-10

Hybrid integration of nanoplasmonic devices with silicon photonic circuits holds promise for a range of applications in on-chip sensing, field-enhanced and nonlinear spectroscopy, and integrated nanophotonic switches. Here, we demonstrate a new regime of photon-plasmon coupling by combining a silicon photonic resonator with plasmonic nanoantennas. Using principles from coherent perfect absorption, we make use of standing-wave light fields to maximize the photon-plasmon interaction strength. Precise placement of the broadband antennas with respect to the narrowband photonic racetrack modes results in controlled hybridization of only a subset of these modes. By combining antennas into groups of radiating dipoles with opposite phase, far-field scattering is effectively suppressed. We achieve ultrafast tuning of photon-plasmon hybridization including reconfigurable routing of the standing-wave input between two output ports. Hybrid photonic-plasmonic resonators provide conceptually new approaches for on-chip integrated nanophotonic devices.

Investigation of postural hypotension due to static prolonged standing in female workers.

PubMed

Kabe, Isamu; Tsuruoka, Hiroko; Tokujitani, Yoko; Endo, Yuichi; Furusawa, Mami; Takebayashi, Toru

2007-07-01

The "Just-in-Time system" improves productivity and efficiency through cost reduction while it makes workers work in a standing posture. The aim of this study was to investigate the prevalence of postural hypotension in females during prolonged standing work, and to discuss preventive methods. Twelve female static standing workers (mean age+/-standard deviation; 32+/-14 yr old), 6 male static standing workers (30+/-4 yr old), 10 female walking workers (27+/-7 yr old) and 9 female desk workers (31+/-5 yr old) in a certain telecommunications equipment manufacturing factory agreed to participate in this study. All participants received an interview with an occupational physician, and performed the standing up test before working and ambulatory blood pressure monitoring (ABPM) while working. Although the blood pressure of the standing up test did not differ among the groups, mean pulse rates on standing up significantly increased in every group. Hypotension rates in the female standing workers' group by ABPM were 9 persons of 12 participants (75%) for systolic blood pressure (SBP), and were 11 persons of 12 participants (92%) for diastolic blood pressure (DBP). There were significantly higher than those in the female desk workers' group, none of 9 participants (0%) for SBP and 2 of 9 participants (22%) for DBP. The hypotension rates both male standing and female walking worker groups did not differ. Because all 8 workers who were found to have postural hypotension by the standing up test had decreased SBP and/or DBP by ABPM, it is suggested that persons at high risk of postural hypotension during standing work could be screened by the standing up test. The mechanism of postural hypotension may be a decrease of venous return due to leg swelling, and neurocardiogenic or vasovagal response. Preventing the congestion of the lower limbs by walking, managing standing time and wearing elastic hose to keep the amount of the venous return could prevent postural hypotension during prolonged standing work.

Potential Energy Curves and Associated Line Shape of Alkali-Metal and Noble-Gas Interactions

DTIC Science & Technology

2014-10-20

spectrum of the diodes. This broadening will have the effect of making the device more efficient. In this text I will use the term OPAL for this type...of device, standing for Optically Pumped Alkali Laser. In the decade since the OPAL was proposed there have been many studies of these systems. For...example, see Beach et al. [2004], Zhdanov et al. [2006], Page et al. [2006], Zhdanov et al. [2008]. During operation of an OPAL an optical source will

Overview of Considerations in Assessing the Biomass Potential of Army Installations.

DTIC Science & Technology

1981-08-01

stage. Will the species grow well in poor soils and on harsh, open sites? Trees that met these standards were then grouped according to their...frequency of fire, (2) reduces the need of fire control methods such as controlled burns, and (3) makes site preparation easier.21 Whole-tree chipping...the "aesthetic" value of the stand is increased.22 The negative effect most often thought to occur with whole-tree chipping is loss of soil nutrients

Detecting leaf pulvinar movements on NDVI time series of desert trees: a new approach for water stress detection.

PubMed

Chávez, Roberto O; Clevers, Jan G P W; Verbesselt, Jan; Naulin, Paulette I; Herold, Martin

2014-01-01

Heliotropic leaf movement or leaf 'solar tracking' occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI), should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern Chile, we studied seasonal and diurnal variations of MODIS and Landsat NDVI time series of plantation stands of the endemic species Prosopis tamarugo Phil., subject to different levels of groundwater depletion. As solar irradiation increased during the day and also during the summer, the paraheliotropic leaves of Tamarugo moved to an erectophile position (parallel to the sun rays) making the NDVI signal to drop. This way, Tamarugo stands with no water stress showed a positive NDVI difference between morning and midday (ΔNDVI mo-mi) and between winter and summer (ΔNDVI W-S). In this paper, we showed that the ΔNDVI mo-mi of Tamarugo stands can be detected using MODIS Terra and Aqua images, and the ΔNDVI W-S using Landsat or MODIS Terra images. Because pulvinar movement is triggered by changes in cell turgor, the effects of water stress caused by groundwater depletion can be assessed and monitored using ΔNDVI mo-mi and ΔNDVI W-S. For an 11-year time series without rainfall events, Landsat ΔNDVI W-S of Tamarugo stands showed a positive linear relationship with cumulative groundwater depletion. We conclude that both ΔNDVI mo-mi and ΔNDVI W-S have potential to detect early water stress of paraheliotropic vegetation.

Detecting Leaf Pulvinar Movements on NDVI Time Series of Desert Trees: A New Approach for Water Stress Detection

PubMed Central

Chávez, Roberto O.; Clevers, Jan G. P. W.; Verbesselt, Jan; Naulin, Paulette I.; Herold, Martin

2014-01-01

Heliotropic leaf movement or leaf ‘solar tracking’ occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI), should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern Chile, we studied seasonal and diurnal variations of MODIS and Landsat NDVI time series of plantation stands of the endemic species Prosopis tamarugo Phil., subject to different levels of groundwater depletion. As solar irradiation increased during the day and also during the summer, the paraheliotropic leaves of Tamarugo moved to an erectophile position (parallel to the sun rays) making the NDVI signal to drop. This way, Tamarugo stands with no water stress showed a positive NDVI difference between morning and midday (ΔNDVImo-mi) and between winter and summer (ΔNDVIW-S). In this paper, we showed that the ΔNDVImo-mi of Tamarugo stands can be detected using MODIS Terra and Aqua images, and the ΔNDVIW-S using Landsat or MODIS Terra images. Because pulvinar movement is triggered by changes in cell turgor, the effects of water stress caused by groundwater depletion can be assessed and monitored using ΔNDVImo-mi and ΔNDVIW-S. For an 11-year time series without rainfall events, Landsat ΔNDVIW-S of Tamarugo stands showed a positive linear relationship with cumulative groundwater depletion. We conclude that both ΔNDVImo-mi and ΔNDVIW-S have potential to detect early water stress of paraheliotropic vegetation. PMID:25188305

The Intelligence Requirements of Psychological Operations in Counterterrorism

DTIC Science & Technology

2008-12-01

10 “Anti-Terror Law No 3713,” Official Gazette, 30 no. 20843 (April 12, 1991), in Beril Dedeoglu, “ Bermuda Triangle : Comparing...make the “Western conspiracy ” aware of the “Islamic community” and make their secret battalions ready for battle. Phase three, “Arising and Standing

Mixed-effects models for estimating stand volume by means of small footprint airborne laser scanner data.

Treesearch

J. Breidenbach; E. Kublin; R. McGaughey; H.-E. Andersen; S. Reutebuch

2008-01-01

For this study, hierarchical data sets--in that several sample plots are located within a stand--were analyzed for study sites in the USA and Germany. The German data had an additional hierarchy as the stands are located within four distinct public forests. Fixed-effects models and mixed-effects models with a random intercept on the stand level were fit to each data...

Making physiological birth possible: birth at a free-standing birth centre in Berlin.

PubMed

Stone, Nancy I

2012-10-01

the practical training in midwifery education in Germany takes place predominantly in hospital delivery wards, where high rates of intervention and caesarean section prevail. When midwives practice birth assistance at free-standing birth centres, they have to make adjustments to what they learned in the clinic to support women without the interventions common to hospital birth. the primary aim of this study was to investigate and describe the approach of midwives practicing birth assistance at a free-standing birth centre. a qualitative approach to data collection and analysis with grounded theory was used which included semi-structured expert interviews and participant observation. Five midwives were interviewed and nine births observed in the research period. The setting was a free-standing birth centre in a large German city with approximately 115 births per year. the midwives all had to re-learn birth assistance when commencing work outside of the hospital. However, having been trained predominantly in hospital maternity wards, they have retained many aspects characteristic of their training. The midwives use technology, although minimal, and medical discourse in combination with 1:1, woman-centred care. The birthing woman and midwife share authority at birth. The fetus is treated as an ally of the mother, suited for birth and cooperative. Through use of objective and subjective criteria, the midwives have their own approach to making physiological birth possible. to prepare midwives to support low-intervention birth, it is necessary to include training in birth assistance with women who birth physiologically, without interventions common to hospital birth. The results of this study would also suggest that the rate of interventions in hospital could be reduced if midwives gain more experience with women birthing without the above-mentioned interventions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Flooding effects on stand development in cypress-tupelo

Treesearch

Richard F. Keim; Thomas J. Dean; Jim L. Chambers

2013-01-01

The effects of inundation on growth of cypress (Taxodium spp.) and tupelo (Nyssa spp.) trees have been extensively researched, but conclusions are often complicated by attendant effects on stand development. Flooding affects development of cypress-tupelo stands by limiting seedling germination and survival, truncating species...

Changing spatial patterns of stand-replacing fire in California conifer forests

Treesearch

Jens T. Stevens; Brandon M. Collins; Jay D. Miller; Malcolm P. North; Scott L. Stephens

2017-01-01

Stand-replacing fire has profound ecological impacts in conifer forests, yet there is continued uncertainty over how best to describe the scale of stand-replacing effects within individual fires, and how these effects are changing over time. In forests where regeneration following stand-replacing fire depends on seed dispersal from surviving trees, the size and shape...

Effects of intermediate-severity disturbance on composition and structure in mixed Pinus-hardwood stands

Treesearch

Benjamin Trammell; Justin Hart; Callie Schweitzer; Daniel C. Dey; Michael Steinberg

2017-01-01

Increasingly, forest managers intend to create or maintain mixed Pinus-hardwood stands. This stand assemblage may be driven by a variety of objectives but is often motivated by the desire to enhance native forest diversity and promote resilience to perturbations. Documenting the effects of natural disturbances on species composition and stand...

Comparisons of musculoskeletal complaints and data entry between a sitting and a sit-stand workstation paradigm.

PubMed

Husemann, Britta; Von Mach, Carolin Yvonne; Borsotto, Daniel; Zepf, Kirsten Isabel; Scharnbacher, Jutta

2009-06-01

Seated working positions are often regarded as a cause for discomfort in the musculoskeletal system. Performing work in different working positions--that is, alternating between sitting and standing (sit-stand workstation paradigm)--could help reduce physical complaints. The questions were whether performing office work partly in a standing position leads to reduced complaints and whether standing would change the efficiency of data entry office work. We investigated the effect of a sit-stand workstation paradigmd during experimental data entry office work on physical and psychological complaints and data entry efficiency by conducting a randomized controlled trial with 60 male participants ages 18 to 35 years. In this experiment, musculoskeletal complaints were reduced by a sit-stand workstation paradigm. A trend could be identified indicating a small but nonsignificant loss of efficiency in data entry while standing. A sit-stand workstation paradigm reduces musculoskeletal complaints without considerably affecting data entry efficiency under the presented study conditions (young male participants, short duration, fixed and controlled sit-stand workstation paradigm, simulated experimental working condition). According to the present data, implementing a sit-stand workstation paradigm can be an effective workplace health intervention to reduce musculoskeletal complaints. This experiment encourages further studies on the effectiveness of a sit-stand workstation paradigm. Experimental research and field studies that prove the reduction of complaints when introducing a sit-stand workstation paradigm in the workplace could be the basis for evidence-based recommendations regarding such interventions.

Acceptability and feasibility of potential intervention strategies for influencing sedentary time at work: focus group interviews in executives and employees.

PubMed

De Cocker, Katrien; Veldeman, Charlene; De Bacquer, Dirk; Braeckman, Lutgart; Owen, Neville; Cardon, Greet; De Bourdeaudhuij, Ilse

2015-02-18

Occupational sitting can be the largest contributor to overall daily sitting time in white-collar workers. With adverse health effects in adults, intervention strategies to influence sedentary time on a working day are needed. Therefore, the present aim was to examine employees' and executives' reflections on occupational sitting and to examine the potential acceptability and feasibility of intervention strategies to reduce and interrupt sedentary time on a working day. Seven focus groups (four among employees, n = 34; three among executives, n = 21) were conducted in a convenience sample of three different companies in Flanders (Belgium), using a semi-structured questioning route in five themes [personal sitting patterns; intervention strategies during working hours, (lunch) breaks, commuting; and intervention approach]. The audiotaped interviews were verbatim transcribed, followed by a qualitative inductive content analysis in NVivo 10. The majority of participants recognized they spend their working day mostly sitting and associated this mainly with musculoskeletal health problems. Participants suggested a variety of possible strategies, primarily for working hours (standing during phone calls/meetings, PC reminders, increasing bathroom use by drinking more water, active sitting furniture, standing desks, rearranging the office) and (lunch) breaks (physical activity, movement breaks, standing tables). However, several barriers were reported, including productivity concerns, impracticality, awkwardness of standing, and the habitual nature of sitting. Facilitating factors were raising awareness, providing alternatives for simply standing, making some strategies obligatory and workers taking some personal responsibility. There are some strategies targeting sedentary time on a working day that are perceived to be realistic and useful. However several barriers emerged, which future trials and practical initiatives should take into account.

Fainting

MedlinePlus

... in older people. Some causes of fainting include Heat or dehydration Emotional distress Standing up too quickly Certain medicines Drop in blood sugar Heart problems When someone faints, make sure that the ...

[Effects of litterfall and root input on soil physical and chemical properties in Pinus massoniana plantations in Three Gorges Reservoir Area, China].

PubMed

Ge, Xiao-Gai; Huang, Zhi-Lin; Cheng, Rui-Mei; Zeng, Li-Xiong; Xiao, Wen-Fa; Tan, Ben-Wang

2012-12-01

An investigation was made on the soil physical and chemical properties in different-aged Pinus massoniana plantations in Three Gorges Reservoir Area under effects of litterfall and roots. The annual litter production in mature stand was 19.4% and 65.7% higher than that in nearly mature and middle-aged stands, respectively. The litter standing amount was in the sequence of mature stand > middle-aged stand > nearly mature stand, while the litter turnover coefficient was in the order of nearly mature stand (0.51) > mature stand (0.40) > middle-aged stand (0.36). The total root biomass, live root biomass, and dead root biomass were the highest in middle-aged stand, and the lowest in nearly mature stand. In middle-aged stand, soil total porosity was the highest, and soil bulk density was the lowest. Soil organic matter and total nitrogen contents were in the order of mature stand > middle-aged stand > nearly mature stand, soil nitrate nitrogen occupied a larger proportion of soil mineral N in nearly mature stand, while ammonium nitrogen accounted more in middle-aged and mature stands. In nearly mature stand, litter production was moderate but turnover coefficient was the highest, and soil nutrient contents were the lowest. In middle-aged stand, root biomass and soil total porosity were the highest, and soil bulk density were the lowest. In mature stand, root biomass was lower while soil nutrient contents were the highest. The increase of root biomass could improve soil physical properties.

Physical characteristics, chemical composition and water contamination potential from Canadian wildfire ash

NASA Astrophysics Data System (ADS)

Santin, Cristina; Doerr, Stefan; Arcenegui, Vicky; Otero, Xose Luis

2017-04-01

Wildland fires leave a powdery residue on the ground: wildfire ash, which consists of mineral materials and charred organic components. Its quantities and characteristics depend mainly on the total amount and type of fuel burnt and the fire characteristics. Up to several tens of tons of ash per hectare have been quantified in different post-fire environments. As a new material present after a wildland fire, ash can have profound effects on ecosystems. It affects biogeochemical cycles, including the carbon cycle, stimulates microbial activity and helps the recovery of vegetation. Ash incorporated into the soil increases soil pH and nutrient pools temporarily and changes soil physical properties such as albedo, soil texture and hydraulic properties. Ash also modifies soil and landscape-scale hydrological behaviour. Its high porosity makes it very effective at absorbing rainfall, but it can also contribute to catastrophic debris flows when ash is mobilised by large storm events. Its 'fragile' nature makes ash very susceptible to wind and water erosion, facilitating its transfer to the hydrological system. Runoff containing ash from burnt areas carries soluble nutrients and pollutants, which can have detrimental impacts on aquatic ecosystems and the supply of potable water. In this presentation we will report for the first time on the physical characteristics, chemical composition and associated water pollution risk from ash produced in four typical Canadian boreal forest fires: two high-intensity fires in jack pine stands, and one high-intensity and one smouldering fire in black spruce stands.

A randomised control trial of the cognitive effects of working in a seated as opposed to a standing position in office workers.

PubMed

Russell, Bridget A; Summers, Mathew J; Tranent, Peter J; Palmer, Matthew A; Cooley, P Dean; Pedersen, Scott J

2016-06-01

Sedentary behaviour is increasing and has been identified as a potential significant health risk, particularly for desk-based employees. The development of sit-stand workstations in the workplace is one approach to reduce sedentary behaviour. However, there is uncertainty about the effects of sit-stand workstations on cognitive functioning. A sample of 36 university staff participated in a within-subjects randomised control trial examining the effect of sitting vs. standing for one hour per day for five consecutive days on attention, information processing speed, short-term memory, working memory and task efficiency. The results of the study showed no statistically significant difference in cognitive performance or work efficiency between the sitting and standing conditions, with all effect sizes being small to very small (all ds < .2). This result suggests that the use of sit-stand workstations is not associated with a reduction in cognitive performance. Practitioner Summary: Although it has been reported that the use of sit-stand desks may help offset adverse health effects of prolonged sitting, there is scant evidence about changes in productivity. This randomised control study showed that there was no difference between sitting and standing for one hour on cognitive function or task efficiency in university staff.

Uav and GIS Based Tool for Collection and Propagation of Seeds Material - First Results

NASA Astrophysics Data System (ADS)

Stereńczak, K.; Mroczek, P.; Jastrzębowski, S.; Krok, G.; Lisańczuk, M.; Klisz, M.; Kantorowicz, W.

2016-06-01

Seed management carried out by The State Forests National Forest Holding is an integral part of rational forest management. Seed collection takes place mainly from stands belonging to first category of forest reproductive material, which is the largest seed base in Poland. In smaller amount, seeds are collected in selective objects of highest forest reproductive material category (selected seed stands, seed orchards). The previous estimation methods of seed crop were based on visual assessment of cones in the stands for their harvest. Following the rules of FRM transfer is additional difficulty of rational seed management which limits the possibility of the use of planting material in Poland. Statements concerning forecast of seed crop and monitoring of seed quality is based on annual reports from the State Forest Service. Forest Research Institute is responsible for preparing and publishing above-mentioned statements. A small extent of its automatization and optimization is a large disadvantage of this procedure. In order to make this process more effective web-based GIS application was designed. Its main performance will give a possibility to upload present-day information on seed efficiency, their spatial pattern and availability. Currently this system is under preparation. As a result, the project team will get a possibility to increase participation of seed material collected from selected seed base and to share good practices on this issue in more efficient way. In the future this will make it possible to obtain greater genetic gain of selection strategy. Additionally, first results presented in literature showed possible use of unmanned aerial system/vehicle (UAS/V) for supporting of seed crop forecast procedure.

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...

Paper birch decline in the Niobrara River Valley, Nebraska: Weather, microclimate, and birch stand conditions

USGS Publications Warehouse

Stroh, Esther D.; Miller, Joel P.

2009-01-01

The Niobrara River Valley in north-central Nebraska supports scattered stands of paper birch (Betula papyrifera Marsh), a species more typical of boreal forests. These birch stands are considered to be relictual populations that have persisted since the end of the Wisconsin glaciation, when regional flora was more boreal in nature (Wright 1970, Kaul and others, 1988). Dieback of canopy-sized birch has been observed throughout the Niobrara Valley in recent years, although no onset dates are documented. The current dieback event probably started around or after the early 1980’s. The study objectives were to understand microclimatic conditions in birch stands relative to nearby weather stations and historic weather conditions, and to assess current health conditions of individual birch trees. Temperature was measured every half-hour from June 2005 through October 2007 in 12 birch stands and individual birch tree health was measured as expressed by percent living canopy in these and 13 additional stands in spring 2006 and 2007. Birch site microclimate was compared to data from a National Weather Service station in Valentine, Nebraska, and to an automated weather station at The Nature Conservancy Niobrara Valley Preserve 24 kilometers north of Johnstown, Nebraska. Historic weather data from the Valentine station and another National Weather Service Station at Ainsworth, Nebraska, were used to reconstruct minimum and maximum temperature at The Nature Conservancy and one microclimate monitoring station using Kalman filtering and smoothing algorithms. Birch stand microclimate differed from local weather stations as well as among stands. Birch health was associated with annual minimum temperature regimes; those stands whose annual daily minimum temperature regimes were most like The Nature Conservancy station contained smaller proportions of living trees. Frequency of freeze/thaw conditions capable of inducing rootlet injury and subsequent crown dieback significantly have increased in the second one-half of the period of record (1978–2007) as compared to the first one-half (1948–1977). River location was associated with birch health; upper river sites had significantly healthier trees than north bank sites. Localized microclimates in the birch stands have likely facilitated the persistence of the birch populations in a region otherwise unsuitable for the species. These microclimate differences may reduce frequency of thaw/freeze conditions that can induce root injury and potential crown dieback. A large population decline in the context of increased frequency of potentially injurious climatic events would make population recovery much more difficult now than from 1948 to 1977, when thaw/freeze conditions were less frequent. These conditions, combined with little evidence of recruitment of young birch and great geographic distances from potential immigrant sources, make the future persistence of birch in the Niobrara River Valley stands uncertain.

13 CFR 124.1013 - How does SBA make disadvantaged status determinations in considering an SDB protest?

Code of Federal Regulations, 2012 CFR

2012-01-01

... status determinations in considering an SDB protest? 124.1013 Section 124.1013 Business Credit and... § 124.1013 How does SBA make disadvantaged status determinations in considering an SDB protest? (a... status determination, and a previous SDB certification will stand. (d) Basis for determination. (1...

13 CFR 124.1013 - How does SBA make disadvantaged status determinations in considering an SDB protest?

Code of Federal Regulations, 2013 CFR

2013-01-01

... status determinations in considering an SDB protest? 124.1013 Section 124.1013 Business Credit and... § 124.1013 How does SBA make disadvantaged status determinations in considering an SDB protest? (a... status determination, and a previous SDB certification will stand. (d) Basis for determination. (1...

13 CFR 124.1013 - How does SBA make disadvantaged status determinations in considering an SDB protest?

Code of Federal Regulations, 2014 CFR

2014-01-01

... status determinations in considering an SDB protest? 124.1013 Section 124.1013 Business Credit and... § 124.1013 How does SBA make disadvantaged status determinations in considering an SDB protest? (a... status determination, and a previous SDB certification will stand. (d) Basis for determination. (1...

Decision Making in a Nuclear Age.

ERIC Educational Resources Information Center

Austill, Chris, Ed.

These activities help high school students develop an understanding of nuclear weapons within the context of human beings making choices. Students learn to evaluate information and to identify the political stand or bias in what they hear and read. To record their own growth and change, students are encouraged to keep a journal. Teachers can…

Making a World of Difference by Looking Locally

ERIC Educational Resources Information Center

Lowenstein, Ethan; Smith, Gregory

2017-01-01

By allowing students to ask critical questions about the places and spaces surrounding them, teachers can empower them to develop problem-solving skills to tackle issues and make a difference in their communities. In this article, Smith and Lowenstein offer three wonderful examples of long-standing environmental place-based education projects that…

Medical Devices Transition to Information Systems: Lessons Learned

PubMed Central

Charters, Kathleen G.

2012-01-01

Medical devices designed to network can share data with a Clinical Information System (CIS), making that data available within clinician workflow. Some lessons learned by transitioning anesthesia reporting and monitoring devices (ARMDs) on a local area network (LAN) to integration of anesthesia documentation within a CIS include the following categories: access, contracting, deployment, implementation, planning, security, support, training and workflow integration. Areas identified for improvement include: Vendor requirements for access reconciled with the organizations’ security policies and procedures. Include clauses supporting transition from stand-alone devices to information integrated into clinical workflow in the medical device procurement contract. Resolve deployment and implementation barriers that make the process less efficient and more costly. Include effective field communication and creative alternatives in planning. Build training on the baseline knowledge of trainees. Include effective help desk processes and metrics. Have a process for determining where problems originate when systems share information. PMID:24199054

JPRS Report, Latin America.

DTIC Science & Technology

1987-06-08

under- stand the phenomena, negotiations, and electoral agreements which occurred during the congress. It is for this reason that we decided to make ...demanded that Brasilia’s attention be directed to him. Dias’ vehemence raises a question: Is the governor trying to make friends for the new ministry, is...conference was convened to encourage discussion and decison - making between the leaders and residents of Amerindian communi- ties, to acquaint Amerindian

Fitting and Calibrating a Multilevel Mixed-Effects Stem Taper Model for Maritime Pine in NW Spain

PubMed Central

Arias-Rodil, Manuel; Castedo-Dorado, Fernando; Cámara-Obregón, Asunción; Diéguez-Aranda, Ulises

2015-01-01

Stem taper data are usually hierarchical (several measurements per tree, and several trees per plot), making application of a multilevel mixed-effects modelling approach essential. However, correlation between trees in the same plot/stand has often been ignored in previous studies. Fitting and calibration of a variable-exponent stem taper function were conducted using data from 420 trees felled in even-aged maritime pine (Pinus pinaster Ait.) stands in NW Spain. In the fitting step, the tree level explained much more variability than the plot level, and therefore calibration at plot level was omitted. Several stem heights were evaluated for measurement of the additional diameter needed for calibration at tree level. Calibration with an additional diameter measured at between 40 and 60% of total tree height showed the greatest improvement in volume and diameter predictions. If additional diameter measurement is not available, the fixed-effects model fitted by the ordinary least squares technique should be used. Finally, we also evaluated how the expansion of parameters with random effects affects the stem taper prediction, as we consider this a key question when applying the mixed-effects modelling approach to taper equations. The results showed that correlation between random effects should be taken into account when assessing the influence of random effects in stem taper prediction. PMID:26630156

Acute effects on cognitive performance following bouts of standing and light-intensity physical activity in a simulated workplace environment.

PubMed

Mullane, Sarah L; Buman, Matthew P; Zeigler, Zachary S; Crespo, Noe C; Gaesser, Glenn A

2017-05-01

To compare acute cognitive effects following bouts of standing (STAND), cycling (CYCLE) and walking (WALK) to a sit-only (SIT) condition. Randomized cross-over full-factorial study. Nine overweight (BMI=29±3kg/m 2 ) adults (30±15years; 7 females, 2 males) completed four conditions (SIT, STAND, WALK and CYCLE) across a 6h period with a 7days washout period between conditions. SIT consisted of uninterrupted sitting. Experimental conditions included intermittent bouts of standing (STAND), cycling (CYCLE) and walking (WALK). A cognitive performance battery (Cogstate) was completed twice in a seated position following bouts of standing and light-intensity physical activity. Mixed-effects models compared between-condition differences in standardized score (z-score), accuracy (%), and speed (log10ms). Cognitive performance z-score and accuracy measures were higher during STAND, CYCLE and WALK (P<0.05) conditions compared to the SIT condition. CYCLE was better than other experimental conditions. Compared to uninterrupted sitting, short bouts of standing or light-intensity cycling and walking may improve acute cognitive performance. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Computerized algorithms for partial cuts

Treesearch

R.L. Ernst; S.L. Stout

1991-01-01

Stand density, stand structure (diameter distribution), and species composition are all changed by intermediate treatments in forest stands. To use computer stand-growth simulators to assess the effects of different treatments on stand growth and development, users must be able to duplicate silviculturally realistic treatments in the simulator. In this paper, we review...

What you don't know about making decisions.

PubMed

Garvin, D A; Roberto, M A

2001-09-01

Most executives think of decision making as a singular event that occurs at a particular point in time. In reality, though, decision making is a process fraught with power plays, politics, personal nuances, and institutional history. Leaders who recognize this make far better decisions than those who persevere in the fantasy that decisions are events they alone control. That said, some decision-making processes are far more effective than others. Most often, participants use an advocacy process, possibly the least productive way to get things done. They view decision making as a contest, arguing passionately for their preferred solutions, presenting information selectively, withholding relevant conflicting data so they can make a convincing case, and standing firm against opposition. Much more powerful is an inquiry process, in which people consider a variety of options and work together to discover the best solution. Moving from advocacy to inquiry requires careful attention to three critical factors: fostering constructive, rather than personal, conflict; making sure everyone knows that their viewpoints are given serious consideration even if they are not ultimately accepted; and knowing when to bring deliberations to a close. The authors discuss in detail strategies for moving from an advocacy to an inquiry process, as well as for fostering productive conflict, true consideration, and timely closure. And they offer a framework for assessing the effectiveness of your process while you're still in the middle of it. Decision making is a job that lies at the very heart of leadership and one that requires a genius for balance: the ability to embrace the divergence that may characterize early discussions and to forge the unity needed for effective implementation.

Unfitness to stand trial decision-making in the extraordinary Chambers in the Courts of Cambodia.

PubMed

Freckelton, Ian; Karagiannakis, Magda

2014-06-01

In the small number of trials for matters such as genocide and crimes against humanity that have taken place before the Extraordinary Chambers in the Courts of Cambodia, by 2014 three occasions had arisen in which the fitness of the accused persons to participate in their trials had become contentious. This is hardly surprising given that the key period of Khmer Rouge government occurred a very long while ago--between 1975 and 1979. The accused persons are all aged. In two instances, the Trial Chamber of the Courts of its own motion sought expert evaluations of the accused persons' fitness to stand trial and, promptly, upon receipt of such reports, determined them to be fit by reference to criteria utilised by the Appeal Chamber of the International Criminal Court for the Former Yugoslavia (the ICTY). In the other instance an accused person, leng Thirith, was found unfit to stand trial and a range of important issues was traversed as to the measures that can properly be taken to try to render a person fit for trial and how legitimate the imposition of detention for that purpose is, and then how legitimate encroachments on a person's civil liberties are to monitor them if there is only a remote possibility that their mental state might improve. It is likely that the balance adopted by the Supreme Court Chamber in the Courts of Cambodia in making significant efforts to render an accused person fit for trial and then in continuing to monitor their mental state when such efforts do not bear fruit, instead of simply releasing them back into the community, will stand as an important precedent for future occasions under international criminal law when issues of fitness to stand trial and how they should be handled arise.

76 FR 55357 - Floor-Standing, Metal-Top Ironing Tables and Certain Parts Thereof From the People's Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-07

...) whether the respondent has autonomy from the government in making decisions regarding the selection of its...) the respondent has autonomy from government in making decisions regarding the selection of management... the surrogate value of by-products sold from NV because the surrogate financial statements on the...

75 FR 55759 - Floor-Standing, Metal-Top Ironing Tables and Certain Parts Thereof From the People's Republic of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-14

... autonomy from the government in making decisions regarding the selection of its management; and (4) whether... Hardware has autonomy from government in making decisions regarding the selection of management, and (4... financial statements on the record of this administrative review contain no references to the treatment of...

Science Fun: Hands-On Science with Dr. Zed.

ERIC Educational Resources Information Center

Penrose, Gordon

This book presents 65 simple, safe, and intriguing hands-on science activities. In doing these simple experiments, children can make a variety of discoveries that will surprise them. It includes many activities from discovering how people see color and what makes people's hair stand on end, to creating a tornado in a jar or a propeller-driven boat…

Better marking means cheaper pruning.

Treesearch

Kenneth R. Eversole

1953-01-01

Careful selection of trees to be pruned can make the difference between profit and loss on the pruning investment, especially in stands where no thinning is contemplated. Expert marking is required to make sure that the pruned trees will grow rapidly. The most important variable influencing the cost of clear wood produced by pruning is growth rate. For example, at 3...

Young Children's Meaning-Making through Drawing and "Telling": Analogies to Filmic Textual Features

ERIC Educational Resources Information Center

Wright, Susan

2007-01-01

Young children's meaning-making is a multifaceted, complex experience, where thought, body and emotion unite. Rich and intricate creations are brought to life through children's formation, communication and interpretation of "signs" which stand for or represent something else. The term drawing-telling is used to describe children's use of a range…

From Readers Theater to Math Dances: Bright Ideas to Make Differentiation Happen

ERIC Educational Resources Information Center

Zuckerbrod, Nancy

2011-01-01

Carol Ann Tomlinson, a professor at the University of Virginia Curry School of Education, has led the push for differentiated instruction and sees a strong commitment by educators to tailoring teaching to student academic levels, learning styles, and personal interests. However, Tomlinson says barriers still stand in the way to making sure every…

Matisse + a Math Connection

ERIC Educational Resources Information Center

Swope, Darcy M.

2009-01-01

It is no wonder that works of art by Henri Matisse appeal to children, as his work has been said to "invite participation." His use of shape, color, design, and composition make his creations stand apart from others. By sharing examples of his line drawings, paintings, sculptures, and paper cutouts, children gain the sense that making art can be a…

Selection of stand variables in southern Maine for making volume estimates from aerial photos

Treesearch

Earl J. Rogers; Gene Avery; Roy A. Chapman

1959-01-01

Aerial photographs are used widely in forest inventories. But there is a continuing need for improving the techniques of photo interpretation and making more efficient use of photographs. When the number or intensity of sample ground plots is controlled by airphoto classifications, a reliable stratification of the timber area is a must.

The correlations of the electronic structure and film growth of 2,7-diocty[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on SiO2.

PubMed

Lyu, Lu; Niu, Dongmei; Xie, Haipeng; Zhao, Yuan; Cao, Ningtong; Zhang, Hong; Zhang, Yuhe; Liu, Peng; Gao, Yongli

2017-01-04

Combining ultraviolet photoemission spectroscopy (UPS), X-ray photoemission spectroscopy (XPS), atomic force microscopy (AFM) and small angle X-ray diffraction (SAXD) measurements, we perform a systematic investigation on the correlations of the electronic structure, film growth and molecular orientation of 2,7-diocty[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on silicon oxide (SiO 2 ). AFM analysis reveals a phase transition of disorderedly oriented molecules in clusters in thinner films to highly ordered standing-up molecules in islands in thicker films. SAXD peaks consistently support the standing-up configuration in islands. The increasing ordering of the molecular orientation with film thickness contributes to the changing of the shape and lowering of the leading edge of the highest occupied molecular orbital (HOMO). The end methyl of the highly ordered standing molecules forms an outward pointing dipole layer which makes the work function (WF) decrease with increasing thickness. The downward shift of the HOMO and a decrease of WF result in unconventional downward band bending and decreased ionization potential (IP). The correlations of the orientation ordering of molecules, film growth and interface electronic structures provide a useful design strategy to improve the performance of C8-BTBT thin film based field effect transistors.

How Does Definition of Minimum Break Length Affect Objective Measures of Sitting Outcomes Among Office Workers?

PubMed

Kloster, Stine; Danquah, Ida Høgstedt; Holtermann, Andreas; Aadahl, Mette; Tolstrup, Janne Schurmann

2017-01-01

Harmful health effects associated with sedentary behavior may be attenuated by breaking up long periods of sitting by standing or walking. However, studies assess interruptions in sitting time differently, making comparisons between studies difficult. It has not previously been described how the definition of minimum break duration affects sitting outcomes. Therefore, the aim was to address how definitions of break length affect total sitting time, number of sit-to-stand transitions, prolonged sitting periods and time accumulated in prolonged sitting periods among office workers. Data were collected from 317 office workers. Thigh position was assessed with an ActiGraph GT3X+ fixed on the right thigh. Data were exported with varying bout length of breaks. Afterward, sitting outcomes were calculated for the respective break lengths. Absolute numbers of sit-to-stand transitions decreased, and number of prolonged sitting periods and total time accumulated in prolonged sitting periods increased, with increasing minimum break length. Total sitting time was not influenced by varying break length. The definition of minimum break length influenced the sitting outcomes with the exception of total sitting time. A standard definition of break length is needed for comparison and interpretation of studies in the evolving research field of sedentary behavior.

A comparison of trunk biomechanics, musculoskeletal discomfort and productivity during simulated sit-stand office work.

PubMed

Karakolis, Thomas; Barrett, Jeff; Callaghan, Jack P

2016-10-01

Sedentary office work has been shown to cause low back discomfort and potentially cause injury. Prolonged standing work has been shown to cause discomfort. The implementation of a sit-stand paradigm is hypothesised to mitigate discomfort and prevent injury induced by prolonged exposure to each posture in isolation. This study explored the potential of sit-stand to reduce discomfort and prevent injury, without adversely affecting productivity. Twenty-four participants performed simulated office work in three different conditions: sitting, standing and sit-stand. Variables measured included: perceived discomfort, L4-L5 joint loading and typing/mousing productivity. Working in a sit-stand paradigm was found to have the potential to reduce discomfort when compared to working in a sitting or standing only configuration. Sit-stand was found to be associated with reduced lumbar flexion during sitting compared to sitting only. Increasing lumbar flexion during prolonged sitting is a known injury mechanism. Therefore, sit-stand exhibited a potentially beneficial response of reduced lumbar flexion that could have the potential to prevent injury. Sit-stand had no significant effect on productivity. Practitioner Summary: This study has contributed foundational elements to guide usage recommendations for sit-stand workstations. The sit-stand paradigm can reduce discomfort; however, working in a sit-stand ratio of 15:5 min may not be the most effective ratio. More frequent posture switches may be necessary to realise the full benefit of sit-stand.

Effects of deer exclosures on oak regeneration in closed-canopy stands

Treesearch

Angela M. Yuska; Kim C. Steiner; James C. Finley

2008-01-01

Studies of the effects of high deer densities on forest regeneration have shown altered species composition and reduced diversity in stands regenerating after harvest. The effects of browsing in fully stocked, undisturbed stands are less well known but important, as establishment of seedlings of oaks and other species prior to disturbance is very important for self-...

Solid Propellant Test Article (SPTA) Test Stand

NASA Technical Reports Server (NTRS)

1991-01-01

This photograph shows the Solid Propellant Test Article (SPTA) test stand with the Modified Nasa Motor (M-NASA) test article at the Marshall Space Flight Center (MSFC). The SPTA test stand, 12-feet wide by 12-feet long by 24-feet high, was built in 1989 to provide comparative performance data on nozzle and case insulation material and to verify thermostructural analysis models. A modified NASA 48-inch solid motor (M-NASA motor) with a 12-foot blast tube and 10-inch throat makes up the SPTA. The M-NASA motor is being used to evaluate solid rocket motor internal non-asbestos insulation materials, nozzle designs, materials, and new inspection techniques. New internal motor case instrumentation techniques are also being evaluated.

Developing silvicultural systems based on partial cutting in western hemlock–Sitka spruce stands of southeast Alaska.

Treesearch

Robert L. Deal; J.C. Tappeiner; Paul E. Hennon

2002-01-01

The effects of partial cutting on species composition, stand structure and growth, tree size distribution, and tree disease and mortality were evaluated on 73 plots in 18 stands that were harvested 12–96 years ago in southeast Alaska. Partially-cut stands had diverse and highly complex stand structures similar to uncut stands. Sitka spruce was maintained in mixed...

Stand development patterns in southern bottomland hardwoods: Management considerations and research needs

Treesearch

Brian R. Lockhart; James S. Meadows; John D. Hodges

2005-01-01

Stand development invloves changes in stand structure over time. Knowledge of stand dvelopment patterns is crucial for effective forest managment, especially of southern botomland hardwood forests. These forests contain more than 70 tree species, many of which ahve commercial timber and wildlife habitat value. In this paper, current techniques in stand development...

The effects of partial cutting on forest plant communities of western hemlock—Sitka spruce stands in southeast Alaska.

Treesearch

Robert L. Deal

2001-01-01

The effects of partial cutting on plant species richness, community structure, and several understory species that are important for deer forage were evaluated on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12–96 years ago when 16- 96% of the former stand basal area was removed. The species richness and community...

More heads choose better than one: Group decision making can eliminate probability matching.

PubMed

Schulze, Christin; Newell, Ben R

2016-06-01

Probability matching is a robust and common failure to adhere to normative predictions in sequential decision making. We show that this choice anomaly is nearly eradicated by gathering individual decision makers into small groups and asking the groups to decide. The group choice advantage emerged both when participants generated responses for an entire sequence of choices without outcome feedback (Exp. 1a) and when participants made trial-by-trial predictions with outcome feedback after each decision (Exp. 1b). We show that the dramatic improvement observed in group settings stands in stark contrast to a complete lack of effective solitary deliberation. These findings suggest a crucial role of group discussion in alleviating the impact of hasty intuitive responses in tasks better suited to careful deliberation.

Transmission loss measurement of acoustic material using time-domain pulse-separation method (L).

PubMed

Sun, Liang; Hou, Hong

2011-04-01

An alternative method for measuring the normal incidence sound transmission loss (nSTL) is presented in this paper based on the time-domain separation of so-called Butterworth pulse with a short-duration time about 1 ms in a standing wave tube. During the generation process of the pulse, inverse filter principle was adopted to compensate the loudspeaker response, besides this, the effect of the characteristics of tube termination can be eliminated through the generation process of the pulse so as to obtain a single plane pulse wave in the standing wave tube which makes the nSTL measurement very simple. A polyurethane foam material with low transmission loss and a kind of rubber material with relatively high transmission loss are used to verify the proposed method. When compared with the traditional two-load method, a relatively good agreement between these two methods can be observed. The main error of this method results from the measuring accuracy of the amplitude of transmission coefficient.

Effect of diameter limits and stand structure on relative density indices: a case study

Treesearch

Robert O. Curtis

2010-01-01

An understory of shade-tolerant species often develops in stands in the Douglas-fir region of western Washington and Oregon and can have a disproportionate effect on relative density indices, such as Reineke stand density index and Curtis relative density. The effects of such understories and of other departures from The even-aged condition are illustrated with...

Modal Analysis with the Mobile Modal Testing Unit

NASA Technical Reports Server (NTRS)

Wilder, Andrew J.

2013-01-01

Recently, National Aeronautics and Space Administration's (NASA's) White Sands Test Facility (WSTF) has tested rocket engines with high pulse frequencies. This has resulted in the use of some of WSTF's existing thrust stands, which were designed for static loading, in tests with large dynamic forces. In order to ensure that the thrust stands can withstand the dynamic loading of high pulse frequency engines while still accurately reporting the test data, their vibrational modes must be characterized. If it is found that they have vibrational modes with frequencies near the pulsing frequency of the test, then they must be modified to withstand the dynamic forces from the pulsing rocket engines. To make this determination the Mobile Modal Testing Unit (MMTU), a system capable of determining the resonant frequencies and mode shapes of a structure, was used on the test stands at WSTF. Once the resonant frequency has been determined for a test stand, it can be compared to the pulse frequency of a test engine to determine whether or not that stand can avoid resonance and reliably test that engine. After analysis of test stand 406 at White Sands Test Facility, it was determined that natural frequencies for the structure are located around 75, 125, and 240 Hz, and thus should be avoided during testing.

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.

The Short-Term Effects of Lying, Sitting and Standing on Energy Expenditure in Women

PubMed Central

POPP, COLLIN J.; BRIDGES, WILLIAM C.; JESCH, ELLIOT D.

2018-01-01

The deleterious health effects of too much sitting have been associated with an increased risk for overweight and obesity. Replacing sitting with standing is the proposed intervention to increase daily energy expenditure (EE). The purpose of this study was to determine the short-term effects of lying, sitting, and standing postures on EE, and determine the magnitude of the effect each posture has on EE using indirect calorimetry (IC). Twenty-eight healthy females performed three separate positions (lying, sitting, standing) in random order. Inspired and expired gases were collected for 45-minutes (15 minutes for each position) using breath-by-breath indirect calorimetry. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured to estimate EE. Statistical analyses used repeat measures ANOVA to analyze all variables and post hoc t-tests. Based on the ANOVA the individual, time period and order term did not result in a statistically significant difference. Lying EE and sitting EE were not different from each other (P = 0.56). However, standing EE (kcal/min) was 9.0 % greater than lying EE (kcal/min) (P = 0.003), and 7.1% greater than sitting EE (kcal/min) (P = 0.02). The energetic cost of standing was higher compared to lying and sitting. While this is statistically significant, the magnitude of the effect of standing when compared to sitting was small (Cohen’s d = 0.31). Short-term standing does not offer an energetic advantage when compared to sitting.

Crafty Corner.

ERIC Educational Resources Information Center

Naturescope, 1986

1986-01-01

Contains three projects that relate to plants and animals of wetlands. Includes instructions and patterns for making cattails, pitcher plants (that really catch flies), and stand-up wetland animals such as insects, birds, crabs, and alligators. (TW)

Shoulder Blade Squeeze (Posture Exercise)

MedlinePlus

... Weight Exercise at Home Shoulder Blade Squeeze Shoulder Blade Squeeze Make an Appointment Ask a Question Find ... it: Stand straight and tall. Pull your shoulder blades back and slightly downward to bring your elbows ...

Pre-outbreak forest conditions mediate the effects of spruce beetle outbreaks on fuels in subalpine forests of Colorado.

PubMed

Mietkiewicz, Nathan; Kulakowski, Dominik; Veblen, Thomas T

2018-03-01

Over the past 30 years, forest disturbances have increased in size, intensity, and frequency globally, and are predicted to continue increasing due to climate change, potentially relaxing the constraints of vegetation properties on disturbance regimes. However, the consequences of the potentially declining importance of vegetation in determining future disturbance regimes are not well understood. Historically, bark beetles preferentially attack older trees and stands in later stages of development. However, as climate warming intensifies outbreaks by promoting growth of beetle populations and compromising tree defenses, smaller diameter trees and stands in early stages of development now are being affected by outbreaks. To date, no study has considered how stand age and other pre-outbreak forest conditions mediate the effects of outbreaks on surface and aerial fuel arrangements. We collected fuels data across a chronosequence of post-outbreak sites affected by spruce beetle (SB) between the 1940s and the 2010s, stratified by young (<130 yr) and old (>130 yr) post-fire stands. Canopy and surface fuel loads were calculated for each tree and stand, and available crown fuel load, crown bulk density, and canopy bulk densities were estimated. Canopy bulk density and density of live canopy individuals were reduced in all stands affected by SB, though foliage loss was proportionally greater in old stands as compared to young stands. Fine surface fuel loads in young stands were three times greater shortly (<30 yr) following outbreak as compared to young stands not affected by outbreak, after which the abundance of fine surface fuels decreased to below endemic (i.e., non-outbreak) levels. In both young and old stands, the net effect of SB outbreaks during the 20th and 21st centuries reduced total canopy fuels and increased stand-scale spatial heterogeneity of canopy fuels following outbreak. Importantly, the decrease in canopy fuels following outbreaks was greater in young post-fire stands than in older stands, suggesting that SB outbreaks may more substantially reduce risk of active crown fire when they affect stands in earlier stages of development. The current study shows that the effects of SB outbreaks on forest structure and on fuel profiles are strongly contingent on pre-outbreak conditions as determined by pre-outbreak disturbance history. © 2018 by the Ecological Society of America.

Conjunction of standing wave and resonance in asymmetric nanowires: a mechanism for thermal rectification and remote energy accumulation.

PubMed

Liu, Yue-Yang; Zhou, Wu-Xing; Chen, Ke-Qiu

2015-12-02

As an important way to control and manage heat transport, thermal rectification has become an elementary issue in the field of phononics and plays a key role in the designing of thermal devices. Here we investigate systematically the standing wave and the accompanying resonance process in asymmetric nanowires to understand the standing wave itself and its great effect on thermal rectification. Results show that the standing wave is sensitive to both the structural and thermal properties of the material, and its great effect on enhancing the thermal rectification is realized not only by the energy-localization nature of the standing wave, but also by the resonance-caused large amplitude and high energy of the standing wave.

A 10 nN resolution thrust-stand for micro-propulsion devices

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

Chakraborty, Subha; Courtney, Daniel G.; Shea, Herbert, E-mail: herbert.shea@epfl.ch

We report on the development of a nano-Newton thrust-stand that can measure up to 100 μN thrust from different types of microthrusters with 10 nN resolution. The compact thrust-stand measures the impingement force of the particles emitted from a microthruster onto a suspended plate of size 45 mm × 45 mm and with a natural frequency over 50 Hz. Using a homodyne (lock-in) readout provides strong immunity to facility vibrations, which historically has been a major challenge for nano-Newton thrust-stands. A cold-gas thruster generating up to 50 μN thrust in air was first used to validate the thrust-stand. Better thanmore » 10 nN resolution and a minimum detectable thrust of 10 nN were achieved. Thrust from a miniature electrospray propulsion system generating up to 3 μN of thrust was measured with our thrust-stand in vacuum, and the thrust was compared with that computed from beam diagnostics, obtaining agreement within 50 nN to 150 nN. The 10 nN resolution obtained from this thrust-stand matches that from state-of-the-art nano-Newton thrust-stands, which measure thrust directly from the thruster by mounting it on a moving arm (but whose natural frequency is well below 1 Hz). The thrust-stand is the first of its kind to demonstrate less than 3 μN resolution by measuring the impingement force, making it capable of measuring thrust from different types of microthrusters, with the potential of easy upscaling for thrust measurement at much higher levels, simply by replacing the force sensor with other force sensors.« less

A 10 nN resolution thrust-stand for micro-propulsion devices

NASA Astrophysics Data System (ADS)

Chakraborty, Subha; Courtney, Daniel G.; Shea, Herbert

2015-11-01

We report on the development of a nano-Newton thrust-stand that can measure up to 100 μN thrust from different types of microthrusters with 10 nN resolution. The compact thrust-stand measures the impingement force of the particles emitted from a microthruster onto a suspended plate of size 45 mm × 45 mm and with a natural frequency over 50 Hz. Using a homodyne (lock-in) readout provides strong immunity to facility vibrations, which historically has been a major challenge for nano-Newton thrust-stands. A cold-gas thruster generating up to 50 μN thrust in air was first used to validate the thrust-stand. Better than 10 nN resolution and a minimum detectable thrust of 10 nN were achieved. Thrust from a miniature electrospray propulsion system generating up to 3 μN of thrust was measured with our thrust-stand in vacuum, and the thrust was compared with that computed from beam diagnostics, obtaining agreement within 50 nN to 150 nN. The 10 nN resolution obtained from this thrust-stand matches that from state-of-the-art nano-Newton thrust-stands, which measure thrust directly from the thruster by mounting it on a moving arm (but whose natural frequency is well below 1 Hz). The thrust-stand is the first of its kind to demonstrate less than 3 μN resolution by measuring the impingement force, making it capable of measuring thrust from different types of microthrusters, with the potential of easy upscaling for thrust measurement at much higher levels, simply by replacing the force sensor with other force sensors.

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

Stand quality management of a water oak plantation in Louisiana: preliminary results following thinning

Treesearch

James S. Meadows; Daniel A., Jr. Skojac

2010-01-01

Stand quality management is a new guiding principle in which thinning prescriptions are based on tree quality rather than on residual stand density. We recently initiated a series of hardwood thinning studies to determine the effects of four stand quality management thinning prescriptions on both stand-level and individual-tree-level growth, quality, and value: (1) no...

Is Making a Risky Choice Based on a Weighting and Adding Process? An Eye-Tracking Investigation

ERIC Educational Resources Information Center

Su, Yin; Rao, Li-Lin; Sun, Hong-Yue; Du, Xue-Lei; Li, Xingshan; Li, Shu

2013-01-01

The debate about whether making a risky choice is based on a weighting and adding process has a long history and is still unresolved. To address this long-standing controversy, we developed a comparative paradigm. Participants' eye movements in 2 risky choice tasks that required participants to choose between risky options in single-play and…

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.

Of graphs and giggles

NASA Astrophysics Data System (ADS)

Commissariat, Tushna

2018-02-01

In recent years, there seems to have been a boom in science stand-up and theatre. The geeky comedy trio who make Festival of the Spoken Nerd deliver shows that are funny, clever and sometimes downright silly.

Effect of plantation density on kraft pulp production from red pine (Pinus resinosa Ait.)

Treesearch

J.Y. Zhu; G.C. Myers

2006-01-01

Red pine (Pinus resinosa Ait.) butt logs from 38 year old research plots were used to study the effect of plantation stand density on kraft pulp production. Results indicate that plantation stand density can affect pulp yield, unrefined pulp mean fibre length, and the response of pulp fibre length to pulp refining. However, the effect of plantation stand density on...

The inverted pendulum model of bipedal standing cannot be stabilized through direct feedback of force and contractile element length and velocity at realistic series elastic element stiffness.

PubMed

van Soest, A J Knoek; Rozendaal, Leonard A

2008-07-01

Control of bipedal standing is typically analyzed in the context of a single-segment inverted pendulum model. The stiffness K (SE) of the series elastic element that transmits the force generated by the contractile elements of the ankle plantarflexors to the skeletal system has been reported to be smaller in magnitude than the destabilizing gravitational stiffness K ( g ). In this study, we assess, in case K (SE) + K ( g ) < 0, if bipedal standing can be locally stable under direct feedback of contractile element length, contractile element velocity (both sensed by muscle spindles) and muscle force (sensed by Golgi tendon organs) to alpha-motoneuron activity. A theoretical analysis reveals that even though positive feedback of force may increase the stiffness of the muscle-tendon complex to values well over the destabilizing gravitational stiffness, dynamic instability makes it impossible to obtain locally stable standing under the conditions assumed.

Effects of two-age management and clearcutting on songbird density and reproductive success

Treesearch

Jeffery V. Nichols; Petra Bohall Wood

1995-01-01

We examined density and reproductive success of passerine species on 7 uncut forest stands and on 12 stands harvested 10-14 years ago on the Monongahela National Forest of West Virginia (6 clearcut stands and 6 stands harvested using 2-age management). In 2-age management, stands resemble a shelterwood cut with 10-30 overstory trees/acre left uncut. Uncut periphery...

Effects of age and stand density of mother trees on early Pinus thunbergii seedling establishment in the coastal zone, China.

PubMed

Mao, Peili; Han, Guangxuan; Wang, Guangmei; Yu, Junbao; Shao, Hongbo

2014-01-01

Effects of age and stand density of mother tree on seed germination, seedling biomass allocation, and seedling growth of Pinus thunbergii were studied. The results showed that age of mother tree did not have significant influences on seed germination, but it was significant on seedling biomass allocation and growth. Seedlings from the minimum and maximum age of mother tree had higher leaf mass ratio and lower root mass ratio than from the middle age of mother tree. Moreover, they also had higher relative height growth rate and slenderness, which were related to their biomass allocation. Stand density of mother tree mainly demonstrated significant effects on seed germination and seedling growth. Seed from higher stand density of mother tree did not decrease germination rate, but had higher mean germination time, indicating that it delayed germination process. Seedlings of higher stand density of mother tree showed higher relative height growth rate and slenderness. These traits of offspring from higher stand density of mother tree were similar to its mother, indicating significant environmental maternal effects. So, mother tree identity of maternal age and environments had important effects on natural regeneration of the coastal P. thunbergii forest.

Effects of Age and Stand Density of Mother Trees on Early Pinus thunbergii Seedling Establishment in the Coastal Zone, China

PubMed Central

Mao, Peili; Han, Guangxuan; Wang, Guangmei; Yu, Junbao; Shao, Hongbo

2014-01-01

Effects of age and stand density of mother tree on seed germination, seedling biomass allocation, and seedling growth of Pinus thunbergii were studied. The results showed that age of mother tree did not have significant influences on seed germination, but it was significant on seedling biomass allocation and growth. Seedlings from the minimum and maximum age of mother tree had higher leaf mass ratio and lower root mass ratio than from the middle age of mother tree. Moreover, they also had higher relative height growth rate and slenderness, which were related to their biomass allocation. Stand density of mother tree mainly demonstrated significant effects on seed germination and seedling growth. Seed from higher stand density of mother tree did not decrease germination rate, but had higher mean germination time, indicating that it delayed germination process. Seedlings of higher stand density of mother tree showed higher relative height growth rate and slenderness. These traits of offspring from higher stand density of mother tree were similar to its mother, indicating significant environmental maternal effects. So, mother tree identity of maternal age and environments had important effects on natural regeneration of the coastal P. thunbergii forest. PMID:24955404

Stand density, tree social status and water stress influence allocation in height and diameter growth of Quercus petraea (Liebl.).

PubMed

Trouvé, Raphaël; Bontemps, Jean-Daniel; Seynave, Ingrid; Collet, Catherine; Lebourgeois, François

2015-10-01

Even-aged forest stands are competitive communities where competition for light gives advantages to tall individuals, thereby inducing a race for height. These same individuals must however balance this competitive advantage with height-related mechanical and hydraulic risks. These phenomena may induce variations in height-diameter growth relationships, with primary dependences on stand density and tree social status as proxies for competition pressure and access to light, and on availability of local environmental resources, including water. We aimed to investigate the effects of stand density, tree social status and water stress on the individual height-circumference growth allocation (Δh-Δc), in even-aged stands of Quercus petraea Liebl. (sessile oak). Within-stand Δc was used as surrogate for tree social status. We used an original long-term experimental plot network, set up in the species production area in France, and designed to explore stand dynamics on a maximum density gradient. Growth allocation was modelled statistically by relating the shape of the Δh-Δc relationship to stand density, stand age and water deficit. The shape of the Δh-Δc relationship shifted from linear with a moderate slope in open-grown stands to concave saturating with an initial steep slope in closed stands. Maximum height growth was found to follow a typical mono-modal response to stand age. In open-grown stands, increasing summer soil water deficit was found to decrease height growth relative to radial growth, suggesting hydraulic constraints on height growth. A similar pattern was found in closed stands, the magnitude of the effect however lowering from suppressed to dominant trees. We highlight the high phenotypic plasticity of growth in sessile oak trees that further adapt their allocation scheme to their environment. Stand density and tree social status were major drivers of growth allocation variations, while water stress had a detrimental effect on height in the Δh-Δc allocation. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of thinning intensities on transpiration and productivity of 50-year-old Pinus koraeinsis stands

NASA Astrophysics Data System (ADS)

Park, J.; Kim, T.; Cho, S.; Ryu, D.; Moon, M.; Kim, H. S.

2015-12-01

This study investigated the effects of thinning intensities on stand transpiration and productivity of 50-year-old Korean pine forests for three years. Forest thinning, which remove some fraction of trees from stand, alters the microclimatic conditions such as radiation distribution within canopy, vapor pressure deficit, and amount of available soil water. These changes influence on the tree water use, and related tree growth. Thinning was conducted on March, 2012 with two intensities (Control, Light-thinning, and Heavy-thinning). Transpiration was estimated from sap flux density, which was measured with Granier-type thermal dissipation sensors. Tree diameter growth was measured with dendrometer, and converted to tree productivity using allometric equations developed specifically in our study sites.The climatic conditions showed remarkable differences among three years. In 2012, total precipitation was highest but spring was dry. 2013 was normal year with frequent rain events. In contrast, 2014 was hot and extremely dry. Stand transpiration was initially decreased ca. 20% and 42% on light-thinning and heavy-thinning stand, respectively. In second year, it gradually recovered in both thinning intensities, and was 19% and 37% lower on light-thinning and heavy-thinning stand, respectively. However, the recovery trends were different between two thinning intensities. Transpiration of heavy-thinning stand was recovered slowly than that of light thinning stand. In 2014, heavy-thinning stand transpired ca. 5% more than control plot in early growing season, but severe drought had negative effects that caused reduction of stand transpiration in thinned stand on late growing season. The tree-level productivity was increased initially ca. 24% and 28% on light-thinning and heavy-thinning stand, respectively. During the following growing seasons, this thinning-induced enhancement of productivity was diminished in light-thinning stand (21% in 2013 and 20% in 2014), but was increased in heavy-thinning stand (49% in 2013 and 56% in 2014). In addition, the relationship between tree diameter and relative growth rate showed opposite trends between heavy thinning and light thinning stands. These results indicate that there are differences in biological reactions with thinning intensities.

Doping of free-standing zinc-blende GaN layers grown by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Novikov, S. V.; Powell, R. E. L.; Staddon, C. R.; Kent, A. J.; Foxon, C. T.

2014-10-01

Currently there is high level of interest in developing of vertical device structures based on the group III nitrides. We have studied n- and p-doping of free-standing zinc-blende GaN grown by plasma-assisted molecular beam epitaxy (PA-MBE). Si was used as the n-dopant and Mg as the p-dopant for zinc-blende GaN. Controllable levels of doping with Si and Mg in free-standing zinc-blende GaN have been achieved by PA-MBE. The Si and Mg doping depth uniformity through the zinc-blende GaN layers have been confirmed by secondary ion mass spectrometry (SIMS). Controllable Si and Mg doping makes PA-MBE a promising method for the growth of conducting group III-nitrides bulk crystals.

Electronic collaboration: Some effects of telecommunication media and machine intelligence on team performance

NASA Technical Reports Server (NTRS)

Wellens, A. Rodney

1991-01-01

Both NASA and DoD have had a long standing interest in teamwork, distributed decision making, and automation. While research on these topics has been pursued independently, it is becoming increasingly clear that the integration of social, cognitive, and human factors engineering principles will be necessary to meet the challenges of highly sophisticated scientific and military programs of the future. Images of human/intelligent-machine electronic collaboration were drawn from NASA and Air Force reports as well as from other sources. Here, areas of common concern are highlighted. A description of the author's research program testing a 'psychological distancing' model of electronic media effects and human/expert system collaboration is given.

Wildland fire effects in silviculturally treated vs. untreated stands of New Mexico and Arizona

Treesearch

Douglas S. Cram; Terrell T. Baker; Jon C. Boren

2006-01-01

Stand-replacement fires, particularly in ponderosa pine (Pinus ponderosa) forests, have replaced highfrequency, low-intensity historical fire regimes. We examined whether forest stands treated recently using silvicultural practices would be (1) less susceptible to stand-replacing crownfires, and (2) more ecologically and functionally resilient...

Stand changes in the first 10 years after seedbed preparation for paper birch

Treesearch

John C. Bjorkbom; John C. Bjorkbom

1972-01-01

Changes may take place rapidly in young forest stands. Stands that appear good may deteriorate unexpectedly: stands that hold little promise initially may suddenly show great potential. The ability to understand and predict such changes increases our ability to prescribe effective silvicultural treatments.

Effects of alternative silvicultural methods on scenic and recreational quality

Treesearch

Mark Brunson; Bo Shelby

1992-01-01

Timber stands harvested using different silvicultural regimes were evaluated for acceptability as places for hiking, camping, and scenic viewing. "New Forestry" stands were more acceptable than stands managed using traditional practices. Stands were rated differently for different uses, with camping quality judged lower than hiking or scenic quality.

Remote sensing of Myriophyllum spicatum L. in a shallow, eutrophic lake

NASA Technical Reports Server (NTRS)

Gustafson, T. D.; Adams, M. S.

1973-01-01

An aerial 35 mm system was used for the acquisition of vertical color and color infrared imagery of the submergent aquatic macrophytes of Lake Wingra, Wisconsin. A method of photographic interpretation of stem density classes is tested for its ability to make standing crop biomass estimates of Myriophyllum spicatum. The results of film image density analysis are significantly correlated with stem densities and standing crop biomass of Myriophyllum and with the biomass of Oedogonium mats. Photographic methods are contrasted with conventional harvest procedures for efficiency and accuracy.

Free-standing oxide superconducting articles

DOEpatents

Wu, X.D.; Muenchausen, R.E.

1993-12-14

A substrate-free, free-standing epitaxially oriented superconductive film including a layer of a template material and a layer of a ceramic superconducting material is provided together with a method of making such a substrate-free ceramic superconductive film by coating an etchable material with a template layer, coating the template layer with a layer of a ceramic superconductive material, coating the layer of ceramic superconductive material with a protective material, removing the etchable material by an appropriate means so that the etchable material is separated from a composite structure including the template layer.

Accumulation of soil organic C and N in planted forests fostered by tree species mixture

NASA Astrophysics Data System (ADS)

Liu, Yan; Lei, Pifeng; Xiang, Wenhua; Yan, Wende; Chen, Xiaoyong

2017-09-01

With the increasing trend of converting monocultures into mixed forests, more and more studies have been carried out to investigate the admixing effects on tree growth and aboveground carbon storage. However, few studies have considered the impact of mixed forests on belowground carbon sequestration, particularly changes in soil carbon and nitrogen stocks as a forest grows. In this study, paired pure Pinus massoniana plantations, Cinnamomum camphora plantations and mixed Pinus massoniana-Cinnamomum camphora plantations at ages of 10, 24 and 45 years were selected to test whether the mixed plantations sequestrate more organic carbon (OC) and nitrogen (N) in soils and whether this admixing effect becomes more pronounced with stand ages. The results showed that tree species identification, composition and stand age significantly affected soil OC and N stocks. The soil OC and N stocks were the highest in mixed Pinus-Cinnamomum stands compared to those in counterpart monocultures with the same age in the whole soil profile or specific soil depth layers (0-10, 10-20 and 20-30 cm) for most cases, followed by Cinnamomum stands and Pinus stands with the lowest. These positive admixing effects were mostly nonadditive. Along the chronosequence, the soil OC stock peaked in the 24-year-old stand and was maintained as relatively stable thereafter. The admixing effects were also the highest at this stage. However, in the topsoil layer, the admixing effects increased with stand ages in terms of soil OC stocks. When comparing mixed Pinus-Cinnamomum plantations with corresponding monocultures within the same age, the soil N stock in mixed stands was 8.30, 11.17 and 31.45 % higher than the predicted mean value estimated from counterpart pure species plantations in 10-, 24- and 45-year-old stands, respectively. This suggests that these admixing effects were more pronounced along the chronosequence.

Effects of thinning intensities on transpiration and productivity of 50-year-old Pinus koraeinsis stands

NASA Astrophysics Data System (ADS)

Park, Juhan; Kim, Taekyu; Moon, Minkyu; Cho, Sungsik; Ryu, Daun; Kim, Hyun Seok

2015-04-01

This study investigated the effects of thinning intensities on stand transpiration and productivity of 50-year-old Korean pine forests for two years. Forest thinning, which removes some fraction of trees from stand, is widely conducted for reducing competition between remaining trees, improving tree productivity, reducing the risk of natural fire, and thus maintaining healthy forest. Forest thinning alters the microclimatic conditions such as radiation distribution within canopy, vapor pressure deficit, and amount of available soil water. These changes influence on the tree water use, and related productivity. Thinning was conducted on March, 2012 with two intensities (Control, Light-thinning (20%), and Heavy-thinning (40% of tree density)). Transpiration was estimated from sap flux density, which was measured with Granier-type thermal dissipation sensors. Tree diameter growth was measured with dendrometer, and converted to tree productivity using allometric equations developed specifically in our study sites. The climatic conditions showed little differences between two years. During the first growing season after thinning, stand transpiration was ca. 20% and 42% lower on light-thinning and heavy-thinning stand, respectively, even though sap flux density were higher in thinned stand. The difference in stand transpiration among treatments showed seasonal trends, so it was larger on summer when soil moisture was abundant due to monsoon, but was diminished on spring and autumn when soil moisture was limited. Tree-level productivity increased ca. 8% and 21% on light-thinning and heavy thinning stand, respectively. However, stand net primary production was ca. 20% lower on light-thinning stand, and ca. 31% on heavy-thinning stand. As a result, water use efficiency increased only in heavy-thinning stand. During the second growing season after thinning, stand transpiration was ca. 19% lower on light-thinning stand, and ca. 37% lower on heavy-thinning stand. The reduction of stand transpiration difference in heavy-thinning stand was caused mainly by increase in sap flux density. Trees in thinned stand showed higher productivity, but the magnitude was ca. 4% on light-thinning stand, and ca. 27% on heavy-thinning stand. Stand net primary production was ca. 23% lower on light-thinning stand, and ca. 28% on heavy-thinning stand. As a result, heavy-thinning stand showed highest water use efficiency. These results indicate that there are differences in biological reactions with thinning intensities.

Acoustic streaming induced by two orthogonal ultrasound standing waves in a microfluidic channel.

PubMed

Doinikov, Alexander A; Thibault, Pierre; Marmottant, Philippe

2018-07-01

A mathematical model is derived for acoustic streaming in a microfluidic channel confined between a solid wall and a rigid reflector. Acoustic streaming is produced by two orthogonal ultrasound standing waves of the same frequency that are created by two pairs of counter-propagating leaky surface waves induced in the solid wall. The magnitudes and phases of the standing waves are assumed to be different. Full analytical solutions are found for the equations of acoustic streaming. The obtained solutions are used in numerical simulations to reveal the structure of the acoustic streaming. It is shown that the interaction of two standing waves leads to the appearance of a cross term in the equations of acoustic streaming. If the phase lag between the standing waves is nonzero, the cross term brings about circular vortices with rotation axes perpendicular to the solid wall of the channel. The vortices make fluid particles rotate and move alternately up and down between the solid wall and the reflector. The obtained results are of immediate interest for acoustomicrofluidic applications such as the ultrasonic micromixing of fluids and the manipulation of microparticles. Copyright © 2018 Elsevier B.V. All rights reserved.

Yield of undamaged slash pine stands in South Florida

Treesearch

O. Gordon Langdon

1961-01-01

Predictions of future timber yields are necessary for formulating management plans and for comparing timber growing with alternative land uses. One useful tool for making these predictions is a set of yield tables.

Long-term precommercial thinning effects on Larix occidentalis (western larch) tree and stand characteristics

Treesearch

Michael S. Schaedel; Andrew J. Larson; David L. R. Affleck; R. Travis Belote; John M. Goodburn; David K. Wright; Elaine Kennedy Sutherland

2017-01-01

Precommercial thinning (PCT) is used to increase tree size and shorten harvest rotation time. Short-term results from PCT studies often show a trade-off between individual-tree growth and net stand yield, while longer-term effects of PCT on tree growth and stand yield are less well documented. We used a 54-year-old PCT study to test long-term effects of forest density...

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

DTIC Science & Technology

2016-10-01

AWARD NUMBER: W81XWH-14-2-0190 TITLE: Testosterone Combined with Electrical Stimulation and Standing: Effect on Muscle and Bone PRINCIPAL...including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and...2015 - 29 Sep 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Testosterone Combined with Electrical Stimulation and Standing: Effect on Muscle and Bone

Scaling up and error analysis of transpiration for Populus euphratica in a desert riparian forest

NASA Astrophysics Data System (ADS)

Si, J.; Li, W.; Feng, Q.

2013-12-01

Water consumption information of the forest stand is the most important factor for regional water resources management. However, water consumption of individual trees are usually measured based on the limited sample trees , so, it is an important issue how to realize eventual scaling up of data from a series of sample trees to entire stand. Estimation of sap flow flux density (Fd) and stand sapwood area (AS-stand) are among the most critical factors for determining forest stand transpiration using sap flow measurement. To estimate Fd, the various links in sap flow technology have great impact on the measurement of sap flow, to estimate AS-stand, an appropriate indirect technique for measuring each tree sapwood area (AS-tree) is required, because it is impossible to measure the AS-tree of all trees in a forest stand. In this study, Fd was measured in 2 mature P. euphratic trees at several radial depths, 0~10, 10~30mm, using sap flow sensors with the heat ratio method, the relationship model between AS-tree and stem diameter (DBH), growth model of AS-tree were established, using investigative original data of DBH, tree-age, and AS-tree. The results revealed that it can achieve scaling up of transpiration from sample trees to entire forest stand using AS-tree and Fd, however, the transpiration of forest stand (E) will be overvalued by 12.6% if using Fd of 0~10mm, and it will be underestimated by 25.3% if using Fd of 10~30mm, it implied that major uncertainties in mean stand Fd estimations are caused by radial variations in Fd. E will be obviously overvalued when the AS-stand is constant, this result imply that it is the key to improve the prediction accuracy that how to simulate the AS-stand changes in the day scale; They also showed that the potential errors in transpiration with a sample size of approximately ≥30 were almost stable for P.euphrtica, this suggests that to make an allometric equation it might be necessary to sample at least 30 trees.

The role of standing variation in geographic convergent adaptation

PubMed Central

Ralph, Peter L.; Coop, Graham

2016-01-01

The extent to which populations experiencing shared selective pressures adapt through a shared genetic response is relevant to many questions in evolutionary biology. In a number of well studied traits and species, it appears that convergent evolution within species is common. In this paper, we explore how standing, genetic variation contributes to convergent genetic responses in a geographically spread population, extending our previous work on the topic. Geographically limited dispersal slows the spread of each selected allele, hence allowing other alleles – newly arisen mutants or present as standing variation – to spread before any one comes to dominate the population. When such alleles meet, their progress is substantially slowed – if the alleles are selectively equivalent, they mix slowly, dividing the species range into a random tessellation, which can be well understood by analogy to a Poisson process model of crystallization. In this framework, we derive the geographic scale over which a typical allele is expected to dominate, the time it takes the species to adapt as a whole, and the proportion of adaptive alleles that arise from standing variation. Finally, we explore how negative pleiotropic effects of alleles before an environment change can bias the subset of alleles that contribute to the species’ adaptive response. We apply the results to the many geographically localized G6PD deficiency alleles thought to confer resistance to malaria, where the large mutational target size makes it a likely candidate for adaptation from standing variation, despite the selective cost of G6PD deficiency alleles in the absence of malaria. We find the numbers and geographic spread of these alleles matches our predictions reasonably well, consistent with the view that they arose from a combination of standing variation and new mutations since the advent of malaria. Our results suggest that much of adaptation may be geographically local even when selection pressures are homogeneous. Therefore, we argue that caution must be exercised when arguing that strongly geographically restricted alleles are necessarily the outcome of local adaptation. We close by discussing the implications of these results for ideas of species coherence and the nature of divergence between species. PMID:26656217

Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

NASA Astrophysics Data System (ADS)

Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S. L.; Poulter, B.; Viovy, N.

2013-04-01

Stand-replacing fires are the dominant fire type in North American boreal forest and leave a historical legacy of a mosaic landscape of different aged forest cohorts. To accurately quantify the role of fire in historical and current regional forest carbon balance using models, one needs to explicitly simulate the new forest cohort that is established after fire. The present study adapted the global process-based vegetation model ORCHIDEE to simulate boreal forest fire CO2 emissions and follow-up recovery after a stand-replacing fire, with representation of postfire new cohort establishment, forest stand structure and the following self-thinning process. Simulation results are evaluated against three clusters of postfire forest chronosequence observations in Canada and Alaska. Evaluation variables for simulated postfire carbon dynamics include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index (LAI), and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). The model simulation results, when forced by local climate and the atmospheric CO2 history on each chronosequence site, generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with measurement accuracy (for CO2 flux ~100 g C m-2 yr-1, for biomass carbon ~1000 g C m-2 and for soil carbon ~2000 g C m-2). We find that current postfire forest carbon sink on evaluation sites observed by chronosequence methods is mainly driven by historical atmospheric CO2 increase when forests recover from fire disturbance. Historical climate generally exerts a negative effect, probably due to increasing water stress caused by significant temperature increase without sufficient increase in precipitation. Our simulation results demonstrate that a global vegetation model such as ORCHIDEE is able to capture the essential ecosystem processes in fire-disturbed boreal forests and produces satisfactory results in terms of both carbon fluxes and carbon stocks evolution after fire, making it suitable for regional simulations in boreal regions where fire regimes play a key role on ecosystem carbon balance.

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 our study has identified habitat use patterns for different species in timber harvests, understanding habitat-specific bird survival is needed to help determine the quality of silvicultural harvests for post-breeding birds.

Evidence of Health Risks Associated with Prolonged Standing at Work and Intervention Effectiveness

PubMed Central

Waters, Thomas R.; Dick, Robert B.

2015-01-01

Purpose Prolonged standing at work has been shown to be associated with a number of potentially serious health outcomes, such as lower back and leg pain, cardiovascular problems, fatigue, discomfort, and pregnancy related health outcomes. Recent studies have been conducted examining the relationship between these health outcomes and the amount of time spent standing while on the job. The purpose of this article was to provide a review of the health risks and interventions for workers and employers that are involved in occupations requiring prolonged standing. A brief review of recommendations by governmental and professional organizations for hours of prolonged standing is also included. Findings Based on our review of the literature, there seems to be ample evidence showing that prolonged standing at work leads to adverse health outcomes. Review of the literature also supports the conclusion that certain interventions are effective in reducing the hazards associated with prolonged standing. Suggested interventions include the use of floor mats, sit-stand workstations/chairs, shoes, shoe inserts and hosiery or stockings. Studies could be improved by using more precise definitions of prolonged standing (e.g., duration, movement restrictions, and type of work), better measurement of the health outcomes and more rigorous study protocols. Conclusion and Clinical Relevance Use of interventions and following suggested guidelines on hours of standing from governmental and professional organizations should reduce the health risks from prolonged standing. PMID:25041875

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

Optimizing any-aged management of mixed-species stands: II. effects of decision criteria

Treesearch

Robert G. Haight; Robert A. Monserud

1990-01-01

The effects of maximum present value and maximum volume objectives on the efficiencies of alternative silvicultural systems are determined by solving any-aged management problems for mixed-conifer stands in the Northern Rocky Mountains. Any-aged management problems are formulated with periodic planting and harvesting controls and without constraints on the stand age or...

Species mixture effects in northern red oak-eastern white pine stands in Maine, USA

Treesearch

Justin Waskiewicz; Laura Kenefic; Aaron Weiskittel; Robert Seymour

2013-01-01

Growth and yield studies of mixed-species stands lack generality, though mixture effects appear to be most likely in stands of species with contrasting traits and/or with vertical stratification. The northern red oak (Quercus rubra L.) - eastern white pine (Pinus strobus L.) forest type of the US Northeast is dominated by species...

Improving the Career Decision-Making Behaviour of Working Class Students: Do Economic Barriers Stand in the Way?

ERIC Educational Resources Information Center

Greenbank, Paul; Hepworth, Sue

2008-01-01

Purpose: This paper aims to examine the extent to which economic factors influence the career decision-making process of working class students. Design/methodology/approach: The study involved an initial survey of 165 final-year students from a range of degree programmes. It was followed by in-depth interviews with 30 working class students.…

Make 'em Laugh (& They'll Learn a Lot More)

ERIC Educational Resources Information Center

Done, Phillip

2006-01-01

Learning and laughter go hand in hand. Teachers certainly do not need to be stand-up comedians and spew out one-liners or dress up like clowns to make their classes fun. A little comedy can bring a lot of joy and learning opportunities to the classroom. In this article, the author shares several strategies on how teachers can put in laughter into…

Much Ado about a Very Small Idea: Straight Talk on Income-Contingent Loans. Canadian Higher Education Report Series

ERIC Educational Resources Information Center

Usher, Alex

2005-01-01

For the first time in the better part of a decade, the idea of making student loans "Income-Contingent" (often referred to as "ICR", which stands for Income-Contingent Repayment) is making a re-appearance on the Canadian policy scene. For those who have long favoured ICRs, this debate will be an opportunity to dust off their…

Fabrication of Si3N4 nanowire membranes: free standing disordered nanopapers and aligned nanowire assemblies

NASA Astrophysics Data System (ADS)

Liu, Haitao; Fang, Minghao; Huang, Zhaohui; Huang, Juntong; Liu, Yan-gai; Wu, Xiaowen

2016-08-01

Herein, ultralong silicon nitride nanowires were synthesized via a chemical vapor deposition method by using the low-cost quartz and silicon powder as raw materials. Simple processes were used for the fabrication of disordered and ordered nanowire membranes of pure silicon nitride nanowires. The nanowires in the disordered nanopapers are intertwined with each other to form a paper-like structure which exhibit excellent flame retardancy and mechanical properties. Fourier-transform infrared spectroscopy and thermal gravity analysis were employed to characterize the refractory performance of the disordered nanopapers. Highly ordered nanowire membranes were also assembled through a three-phase assembly approach which make the Si3N4 nanowires have potential use in textured ceramics and semiconductor field. Moreover, the surface nanowires can also be modified to be hydrophobic; this characteristic make the as-prepared nanowires have the potential to be assembled by the more effective Langmuir-Blodgett method and also make the disordered nanopapers possess a super-hydrophobic surface.

Effects of peanut stand uniformity and herbicide regime on weed management and yield

USDA-ARS?s Scientific Manuscript database

Crop stand directly affects ability of any crop to compete with weeds. To capture this form of cultural weed control, final crop stands need to be uniform. Peanut stands are frequently non-uniform, despite the use of precision vacuum planters. Trials were conducted from 2009 through 2011 in Tifto...

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.

A Control Law Design Method Facilitating Control Power, Robustness, Agility, and Flying Qualities Tradeoffs: CRAFT

NASA Technical Reports Server (NTRS)

Murphy, Patrick C.; Davidson, John B.

1998-01-01

A multi-input, multi-output control law design methodology, named "CRAFT", is presented. CRAFT stands for the design objectives addressed, namely, Control power, Robustness, Agility, and Flying Qualities Tradeoffs. The methodology makes use of control law design metrics from each of the four design objective areas. It combines eigenspace assignment, which allows for direct specification of eigenvalues and eigenvectors, with a graphical approach for representing the metrics that captures numerous design goals in one composite illustration. Sensitivity of the metrics to eigenspace choice is clearly displayed, enabling the designer to assess the cost of design tradeoffs. This approach enhances the designer's ability to make informed design tradeoffs and to reach effective final designs. An example of the CRAFT methodology applied to an advanced experimental fighter and discussion of associated design issues are provided.

Transportation Economic Trends

DOT National Transportation Integrated Search

2016-12-12

Transportation plays a vital role in the American economy: it makes economic activity possible, and serves as a major economic activity in its own right. This report is BTSs first stand-alone volume on transportation and the economy, and uses a va...

Unfair Lineups Make Witnesses More Likely to Confuse Innocent and Guilty Suspects.

PubMed

Colloff, Melissa F; Wade, Kimberley A; Strange, Deryn

2016-09-01

Eyewitness-identification studies have focused on the idea that unfair lineups (i.e., ones in which the police suspect stands out) make witnesses more willing to identify the police suspect. We examined whether unfair lineups also influence subjects' ability to distinguish between innocent and guilty suspects and their ability to judge the accuracy of their identification. In a single experiment (N = 8,925), we compared three fair-lineup techniques used by the police with unfair lineups in which we did nothing to prevent distinctive suspects from standing out. Compared with the fair lineups, doing nothing not only increased subjects' willingness to identify the suspect but also markedly impaired subjects' ability to distinguish between innocent and guilty suspects. Accuracy was also reduced at every level of confidence. These results advance theory on witnesses' identification performance and have important practical implications for how police should construct lineups when suspects have distinctive features. © The Author(s) 2016.

Schlieren imaging of the standing wave field in an ultrasonic acoustic levitator

NASA Astrophysics Data System (ADS)

Rendon, Pablo Luis; Boullosa, Ricardo R.; Echeverria, Carlos; Porta, David

2015-11-01

We consider a model of a single axis acoustic levitator consisting of two cylinders immersed in air and directed along the same axis. The first cylinder has a flat termination and functions as a sound emitter, and the second cylinder, which is simply a refector, has the side facing the first cylinder cut out by a spherical surface. By making the first cylinder vibrate at ultrasonic frequencies a standing wave is produced in the air between the cylinders which makes it possible, by means of the acoustic radiation pressure, to levitate one or several small objects of different shapes, such as spheres or disks. We use schlieren imaging to observe the acoustic field resulting from the levitation of one or several objects, and compare these results to previous numerical approximations of the field obtained using a finite element method. The authors acknowledge financial support from DGAPA-UNAM through project PAPIIT IN109214.

High temperature dependence of thermal transport in graphene foam.

PubMed

Li, Man; Sun, Yi; Xiao, Huying; Hu, Xuejiao; Yue, Yanan

2015-03-13

In contrast to the decreased thermal property of carbon materials with temperature according to the Umklapp phonon scattering theory, highly porous free-standing graphene foam (GF) exhibits an abnormal characteristic that its thermal property increases with temperature above room temperature. In this work, the temperature dependence of thermal properties of free-standing GF is investigated by using the transient electro-thermal technique. Significant increase for thermal conductivity and thermal diffusivity from ∼0.3 to 1.5 W m(-1) K(-1) and ∼4 × 10(-5) to ∼2 × 10(-4) m(2) s(-1) respectively is observed with temperature from 310 K to 440 K for three GF samples. The quantitative analysis based on a physical model for porous media of Schuetz confirms that the thermal conductance across graphene contacts rather than the heat conductance inside graphene dominates thermal transport of our GFs. The thermal expansion effect at an elevated temperature makes the highly porous structure much tighter is responsible for the reduction in thermal contact resistance. Besides, the radiation heat exchange inside the pores of GFs improves the thermal transport at high temperatures. Since free-standing GF has great potential for being used as supercapacitor and battery electrode where the working temperature is always above room temperature, this finding is beneficial for thermal design of GF-based energy applications.

Using stand/sit workstations in classrooms: lessons learned from a pilot study in Texas.

PubMed

Blake, Jamilia J; Benden, Mark E; Wendel, Monica L

2012-01-01

Childhood obesity has grown into a national epidemic since the 1980s. Many school-based intervention efforts that target childhood obesity involve curriculum and programming that demands instructional time, which disincentivizes school participation. Stand-biased classrooms are an environmental intervention that promotes standing rather than sitting by utilizing standing height desks that allow students to stand during normal classroom activities. The quasi-experimental pilot study was conducted in 5 first-grade classrooms in a Texas elementary school, with 2 control classrooms, 2 treatment classrooms, and 1 classroom that was a control in the fall and treatment in the spring (to allow for within-group comparisons). This intervention has been shown effective in significantly increasing caloric expenditure. In addition, the present study reveals potential behavioral effects from standing. This article presents lessons learned from the pilot study that may prove useful for others implementing similar interventions and calls for additional research on the academic benefits of standing for students.

Social rank and social cooperation: Impact of social comparison processes on cooperative decision-making

PubMed Central

Sanfey, Alan G.

2017-01-01

Successful navigation of our complex social world requires the capability to recognize and judge the relative status of others. Hence, social comparison processes are of great importance in our interactions, informing us of our relative standing and in turn potentially motivating our behavior. However, so far few studies have examined in detail how social comparison can influence interpersonal decision-making. One aspect of social decision-making that is of particular importance is cooperative behavior, and identifying means of maintaining and promoting cooperation in the provision of public goods is of vital interest to society. Here, we manipulated social comparison by grading performance rankings on a reaction time task, and then measured cooperative decisions via a modified Public Goods Game (PGG). Findings revealed that individuals ranked highest tended to be more cooperative as compared to those who placed in the bottom rank. Interestingly, this effect was regardless of whether the comparison group members were the subsequent players in the PGG or not, and this effect was stronger in those with higher social orientation. In summary, the present research shows how different social comparison processes (assessed via social rankings) can operate in our daily interaction with others, demonstrating an important effect on cooperative behavior. PMID:28388684

Effect of crown class and habitat type on climate-growth relationships of ponderosa pine and Douglas-fir

Treesearch

Gunnar C. Carnwath; David W. Peterson; Cara R. Nelson

2012-01-01

There is increasing interest in actively managing forests to increase their resilience to climate-related changes. Although forest managers rely heavily on the use of silvicultural treatments that manipulate stand structure and stand dynamics to modify responses to climate change, few studies have directly assessed the effects of stand structure or canopy position on...

Effects of subsoiling on woody roots of Jeffrey pines on two different soil types

Treesearch

W.J. Otrosina; Shi-Jean S. Sung

1995-01-01

This study was initiated to determine the long term effects of subsoiling to alleviate soil compaction due to use of mechanized harvesting equipment in forest stands. Two stands having a predominance of 90 to 110 year old Jeffrey pines (Pinus jeffreyi Grev. & Balf.) were selected for this investigation. Each stand was located on the Milford...

Acoustic Evaluation of Thinning and Biosolid Fertilization Effects on Wood Quality of a Douglas-fir stand

Treesearch

Xiping Wang; Robert J. Ross; Steve Verrill; Eini Lowell; Jamie Barbour

2015-01-01

In this study, we examined the potential of using a time-of-flight (TOF) acoustic wave method to evaluate thinning and biosolid fertilization effects on acoustic velocity of trees and modulus of elasticity (MOE) of structural lumber in a 76-year-old Douglas-fir (Pseudotsuga menziesii, (Mirb., Franco)) experimental stand. The stand consisted of four...

Effects of stand density on top height estimation for ponderosa pine

Treesearch

Martin Ritchie; Jianwei Zhang; Todd Hamilton

2012-01-01

Site index, estimated as a function of dominant-tree height and age, is often used as an expression of site quality. This expression is assumed to be effectively independent of stand density. Observation of dominant height at two different ponderosa pine levels-of-growing-stock studies revealed that top height stability with respect to stand density depends on the...

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...

The Relation of Growth to Stand Density in Natural Loblolly Pine Stands

Treesearch

K.F. Wenger; T.C. Evans; T. Lotti; R.W. Cooper; E.V. Brender

1958-01-01

This is a progress report of a regional study on growing-space requirements for natural stands of loblolly pine (Pinus taeda L.).A primary objective is to measure the effects of residual stand density, obtained naturally or by cutting, during intermediate ages, upon volume yield and total production. By imposing real values and costs upon...

Paper birch: Sentinels of climate change in the Niobrara River Valley, Nebraska

USGS Publications Warehouse

Stroh, Esther D.

2011-01-01

The Niobrara River Valley in the northern Great Plains supports scattered stands of paper birch (Betula papyrifera Marsh), a species more typical of boreal forests. These birch stands are considered to be relictual populations that have persisted since the end of the Wisconsin glaciation. Localized summer microclimates have likely facilitated the persistence of birch populations in a region otherwise unsuitable for the species. Dieback of canopy-sized birch has been observed throughout the valley in recent years, although no onset dates are documented. Changes in spring weather patterns may be causing rootlet injury so that trees die in spite of the still-cool summer microclimates. Current weather patterns, combined with little evidence of recruitment of young birch and great geographic distances from potential immigrant sources, make the future persistence of birch in the Niobrara River Valley stands uncertain.

Characteristics of Southern Hemisphere 200 mb flow as determined from satellite data

NASA Technical Reports Server (NTRS)

Adler, R. F.

1976-01-01

Characteristics of Southern Hemisphere 200 mb flow are examined using geopotential height fields constructed with the aid of satellite based thermal structure. Similar Northern Hemisphere, satellite based fields are developed in order to make interhemispheric comparisons. Results indicate that both the zonal and meridional components of the S.H. eddy kinetic energy are as large as their N.H. counterparts. In winter the principal interhemispheric difference with respect to eddy kinetic energy is that the S.H. standing eddies are much less important only to the meridional component. Zonal component standing energy is about equal in the two hemispheres. In summer the S.H. has larger zonal eddy kinetic energy than the N.H. and smaller standing eddy contributions in both components. The meridional spectra show a preference for intermediate size transient waves.

Seven years later: effects of wildfire in a young stand of Virginia pine and hardwoods

Treesearch

Richard H. Fenton

1960-01-01

In November 1952 a hot surface fire burned through part of a 30-year-old Virginia pine-hardwood stand near Beltsville, Md. Observations were made for the next 2 years to evaluate the effects of this type of fire under these stand conditions. The main direct effects during the 2 years, as reported by Church in 1955, were: 45 percent mortality of trees 1 inch d.b.h. and...

Tree species diversity and its relationship to stand parameters and geomorphology features in the eastern Black Sea region forests of Turkey.

PubMed

Ozcelik, Ramazan; Gul, Altay Ugur; Merganic, Jan; Merganicova, Katarina

2008-05-01

We studied the effects of stand parameters (crown closure, basal area, stand volume, age, mean stand diameter number of trees, and heterogeneity index) and geomorphology features (elevation, aspect and slope) on tree species diversity in an example of untreated natural mixed forest stands in the eastern Black Sea region of Turkey. Tree species diversity and basal area heterogeneity in forest ecosystems are quantified using the Shannon-Weaver and Simpson indices. The relationship between tree species diversity basal area heterogeneity stand parameters and geomorphology features are examined using regression analysis. Our work revealed that the relationship between tree species diversity and stand parameters is loose with a correlation coefficient between 0.02 and 0.70. The correlation of basal area heterogeneity with stand parameters fluctuated between 0.004 and 0.77 (R2). According to our results, stands with higher tree species diversity are characterised by higher mean stand diameter number of diameter classes, basal area and lower homogeneity index value. Considering the effect of geomorphology features on tree species or basal area heterogeneity we found that all investigated relationships are loose with R < or = 0.24. A significant correlation was detected only between tree species diversity and aspect. Future work is required to verify the detected trends in behaviour of tree species diversity if it is to estimate from the usual forest stand parameters and topography characteristics.

Earth science: Making a mountain out of a plateau

NASA Astrophysics Data System (ADS)

Sinclair, Hugh

2017-02-01

A theory proposed in 2015 suggested that relatively flat surfaces in mountain ranges were formed by the reorganization of river networks. A fresh analysis rebuts this idea, reigniting discussion of a long-standing problem in Earth science.

3 CFR 8456 - Proclamation 8456 of November 20, 2009. National Family Week, 2009

Code of Federal Regulations, 2010 CFR

2010-01-01

... families meet the demands of modern life, increase their self-sufficiency, and achieve their full potential..., standing united to make our Nation a place of hope and opportunity for future generations. NOW, THEREFORE...

An annotated bibliography of thinning literature.

Treesearch

Bryce J. Stokes

1992-01-01

This bibliography is a general review of thinning with an emphasis on harvesting in the southern United States. It was developed to aid the decision-making process of foresters and as a basis for continued research in thinning of pine stands.

Astronaut John Young during final suiting operations for Apollo 10 mission

NASA Technical Reports Server (NTRS)

1969-01-01

A technician attaches hose from test stand to spacesuit of Astronaut John W. Young, Apollo 10 command module pilot, during final suiting operations for the Apollo 10 lunar orbit mission. Another technician makes adjustment behind Young.

32 CFR 242.9 - Academic, intellectual, and personal requirements for admission to advanced standing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... aptitude and motivation for a career in medicine in the Uniformed Services will be prime considerations in making admissions decisions. Only the most promising of candidates will be accepted, as judged by...

DSCOVR Spacecraft Arrival, Offload, & Unpacking

NASA Image and Video Library

2014-11-20

NOAA’s Deep Space Climate Observatory spacecraft, or DSCOVR, wrapped in plastic and secured onto a portable work stand, makes a short trek from the airlock of Building 2 to the high bay of Building 1 at the Astrotech payload processing facility.

Public Relations: Ketchum brands new product with innovative PR strategy.

PubMed

2006-01-01

Novartis Pharmaceuticals tapped publis relations (PR) giant Ketchum earlier this year to spearhead a marketing campaign that would make its new U.S. Food and Drug Administration-approved prescription-based medication, Enablex, stand out among the crowd in over active bladder (OAB) treatment. OAB is a disorder that affects an estimated 33 million Americans making this treatment highly in demand with consumers and highly competitive with other pharmaceutical companies.

Assessment: Give Me a Place to Stand, and I Will Move the Earth

DTIC Science & Technology

2012-06-01

Theory , and Policy Keywords: C2 agility, bounded rationality, heuristics, uncertainty, assessment Authors: Erik Bjurström Mälardalen...of making decisions. Although the notion of bounded rationality and its associated theory rendered Herbert Simon the 1978 Nobel prize in economics...future and represents a more structuralistic approach. While making predictions about the future is often necessary it is not feasible as a general

Protective Effects of the Launch/Entry Suit (LES) and the Liquid Cooling Garment(LCG) During Re-entry and Landing After Spaceflight

NASA Technical Reports Server (NTRS)

Perez, Sondra A.; Charles, John B.; Fortner, G. William; Hurst, Victor, IV; Meck, Janice V.

2002-01-01

Heart rate and arterial pressure were measured during shuttle re-entry, landing and initial standing in crewmembers with and without inflated anti-g suits and with and without liquid cooling garments (LCG). Preflight, three measurements were obtained seated, then standing. Prior to and during re-entry, arterial pressure and heart rate were measured every five minutes until wheels stop (WS). Then crewmembers initiated three seated and three standing measurements. In subjects without inflated anti-g suits, SBP and DBP were significantly lower during preflight standing (P = 0.006; P = 0.001 respectively) and at touchdown (TD) (P = 0.001; P = 0.003 respectively); standing SBP was significantly lower after WS. on-LeG users developed significantly higher heart rates during re-entry (P = 0.029, maxG; P = 0.05, TD; P = 0.02, post-WS seated; P = 0.01, post-WS standing) than LCG users. Our data suggest that the anti-g suit is effective, but the combined anti-g suit with LCG is more effective.

High-quality Health Information Provision for Stroke Patients.

PubMed

Du, Hong-Sheng; Ma, Jing-Jian; Li, Mu

2016-09-05

High-quality information provision can allow stroke patients to effectively participate in healthcare decision-making, better manage the stroke, and make a good recovery. In this study, we reviewed information needs of stroke patients, methods for providing information to patients, and considerations needed by the information providers. The literature concerning or including information provision for patients with stroke in English was collected from PubMed published from 1990 to 2015. We included all the relevant articles on information provision for stroke patients in English, with no limitation of study design. Stroke is a major public health concern worldwide. High-quality and effective health information provision plays an essential role in helping patients to actively take part in decision-making and healthcare, and empowering them to effectively self-manage their long-standing chronic conditions. Different methods for providing information to patients have their relative merits and suitability, and as a result, the effective strategies taken by health professionals may include providing high-quality information, meeting patients' individual needs, using suitable methods in providing information, and maintaining active involvement of patients. It is suggested that to enable stroke patients to access high-quality health information, greater efforts need to be made to ensure patients to receive accurate and current evidence-based information which meets their individual needs. Health professionals should use suitable information delivery methods, and actively involve stroke patients in information provision.

Quantifying structural and physiological controls on variation in canopy transpiration among planted pine and hardwood species in the southern Appalachians

Treesearch

Chelcy R. Ford; Robert M. Hubbard; James M. Vose

2010-01-01

Recent studies have shown that planted pine stands exhibit higher evapotranspiration (ET) and are more sensitive to climatic conditions compared with hardwood stands. Whether this is due to management and stand effects, biological effects or their interaction is poorly understood. We estimated growing season canopy- and sap flux-scaled leaf-level transpiration (Ec and...

Effects of thinning a 55-year-old western white pine stand

Treesearch

Marvin W. Foiles

1956-01-01

The first experiment in thinning western white pine (Pinus monticola Dougl.) was planned and established by J. A. Larson and D. R. Brewster in 1914 in a 55-year-old stand on the Priest River Experimental Forest, Idaho. It was designed to compare the effects of three thinning treatments on volume and quality growth, and on total volume production with an unthinned stand...

Individual tree size inequality enhances aboveground biomass in homegarden agroforestry systems in the dry zone of Sri Lanka.

PubMed

Ali, Arshad; Mattsson, Eskil

2017-01-01

Individual tree size variation, which is generally quantified by variances in tree diameter at breast height (DBH) and height in isolation or conjunction, plays a central role in ecosystem functioning in both controlled and natural environments, including forests. However, none of the studies have been conducted in homegarden agroforestry systems. In this study, aboveground biomass, stand quality, cation exchange capacity (CEC), DBH variation, and species diversity were determined across 45 homegardens in the dry zone of Sri Lanka. We employed structural equation modeling (SEM) to test for the direct and indirect effects of stand quality and CEC, via tree size inequality and species diversity, on aboveground biomass. The SEM accounted for 26, 8, and 1% of the variation in aboveground biomass, species diversity and DBH variation, respectively. DBH variation had the strongest positive direct effect on aboveground biomass (β=0.49), followed by the non-significant direct effect of species diversity (β=0.17), stand quality (β=0.17) and CEC (β=-0.05). There were non-significant direct effects of CEC and stand quality on DBH variation and species diversity. Stand quality and CEC had also non-significant indirect effects, via DBH variation and species diversity, on aboveground biomass. Our study revealed that aboveground biomass substantially increased with individual tree size variation only, which supports the niche complementarity mechanism. However, aboveground biomass was not considerably increased with species diversity, stand quality and soil fertility, which might be attributable to the adaptation of certain productive species to the local site conditions. Stand structure shaped by few productive species or independent of species diversity is a main determinant for the variation in aboveground biomass in the studied homegardens. Maintaining stand structure through management practices could be an effective approach for enhancing aboveground biomass in these dry zone homegarden agroforestry systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessing the effects of management on forest growth across France: insights from a new functional-structural model.

PubMed

Guillemot, Joannès; Delpierre, Nicolas; Vallet, Patrick; François, Christophe; Martin-StPaul, Nicolas K; Soudani, Kamel; Nicolas, Manuel; Badeau, Vincent; Dufrêne, Eric

2014-09-01

The structure of a forest stand, i.e. the distribution of tree size features, has strong effects on its functioning. The management of the structure is therefore an important tool in mitigating the impact of predicted changes in climate on forests, especially with respect to drought. Here, a new functional-structural model is presented and is used to assess the effects of management on forest functioning at a national scale. The stand process-based model (PBM) CASTANEA was coupled to a stand structure module (SSM) based on empirical tree-to-tree competition rules. The calibration of the SSM was based on a thorough analysis of intersite and interannual variability of competition asymmetry. The coupled CASTANEA-SSM model was evaluated across France using forest inventory data, and used to compare the effect of contrasted silvicultural practices on simulated stand carbon fluxes and growth. The asymmetry of competition varied consistently with stand productivity at both spatial and temporal scales. The modelling of the competition rules enabled efficient prediction of changes in stand structure within the CASTANEA PBM. The coupled model predicted an increase in net primary productivity (NPP) with management intensity, resulting in higher growth. This positive effect of management was found to vary at a national scale across France: the highest increases in NPP were attained in forests facing moderate to high water stress; however, the absolute effect of management on simulated stand growth remained moderate to low because stand thinning involved changes in carbon allocation at the tree scale. This modelling approach helps to identify the areas where management efforts should be concentrated in order to mitigate near-future drought impact on national forest productivity. Around a quarter of the French temperate oak and beech forests are currently in zones of high vulnerability, where management could thus mitigate the influence of climate change on forest yield.

Effects of low thinning in Atlantic white-cedar stands

Treesearch

G. T. Bamford; S. Little

1960-01-01

Atlantic white-cedar typically grows in dense stands. In southern New Jersey, young stands commonly contain several thousand trees per acre, and at ages around 60 years there still may be 1,000 or more trees per acre.

Stand age and habitat influences on salamanders in Appalachian cove hardwood forests

Treesearch

W. Mark Ford; Brian R. Chapman; Michael A. Menzel; Richard H. Odom

2002-01-01

We surveyed cove hardwood stands aged 15, 25, 50, and ≥85 years following clearcutting in the southern Appalachian Mountains of northern Georgia to assess the effects of stand age and stand habitat characteristics on salamander communities using drift-fence array and pitfall methodologies from May 1994 to April 1995. Over a 60,060 pitfall trapnight effort, we...

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...

NDE of logs and standing trees using new acoustic tools : technical application and results

Treesearch

Peter Carter; Xiping Wang; Robert J. Ross; David Briggs

2005-01-01

The new Director ST300 provides a means to efficiently assess stands for stiffness and related wood properties based on standing tree acoustic velocily measures, and can be easily integrated with pre-harvest and earlier stand assessments. This provides for effective valuation for forest sale, stumpage purchase, harvest planning, and ranking of progeny or clones in tree...

Effects of stand and inter-specific stocking on maximizing standing tree carbon stocks in the eastern United States

Treesearch

Christopher W. Woodall; Anthony W. D' Amato; John B. Bradford; Andrew O. Finley

2011-01-01

There is expanding interest in management strategies that maximize forest carbon (C) storage to mitigate increased atmospheric carbon dioxide. The tremendous tree species diversity and range of stand stocking found across the eastern United States presents a challenge for determining optimal combinations for the maximization of standing tree C storage. Using a...

Effect of crown growing space and age on the growth of northern red oak

Treesearch

Gary W. Miller

1997-01-01

Cultural practices can be applied in even-age stands to reallocate site resources to selected crop trees. Precornrnercial thinning in sapling stands can increase diameter growth and improve species composition of trees in the main canopy. Commercial thinning in sawtimber stands also increases diameter growth of crop trees, improves residual stand quality, and removes...

Winter wheat stand density determination and yield estimates from handheld and airborne scanners. [Montana

NASA Technical Reports Server (NTRS)

Aase, J. K.; Millard, J. P.; Siddoway, F. H. (Principal Investigator)

1982-01-01

Radiance measurements from handheld (Exotech 100-A) and air-borne (Daedalus DEI 1260) radiometers were related to wheat (Triticum aestivum L.) stand densities (simulated winter wheat winterkill) and to grain yield for a field located 11 km northwest of Sidney, Montana, on a Williams loam soil (fine-loamy, mixed Typic Argiborolls) where a semidwarf hard red spring wheat cultivar was needed to stand. Radiances were measured with the handheld radiometer on clear mornings throughout the growing season. Aircraft overflight measurements were made at the end of tillering and during the early stem extension period, and the mid-heading period. The IR/red ratio and normalized difference vegetation index were used in the analysis. The aircraft measurements corroborated the ground measurements inasmuch as wheat stand densities were detected and could be evaluated at an early enough growth stage to make management decision. The aircraft measurements also corroborated handheld measurements when related to yield prediction. The IR/red ratio, although there was some growth stage dependency, related well to yield when measured from just past tillering until about the watery-ripe stage.

Validation of the VitaBit Sit–Stand Tracker: Detecting Sitting, Standing, and Activity Patterns

PubMed Central

Plasqui, Guy

2018-01-01

Sedentary behavior (SB) has detrimental consequences and cannot be compensated for through moderate-to-vigorous physical activity (PA). In order to understand and mitigate SB, tools for measuring and monitoring SB are essential. While current direct-to-customer wearables focus on PA, the VitaBit validated in this study was developed to focus on SB. It was tested in a laboratory and in a free-living condition, comparing it to direct observation and to a current best-practice device, the ActiGraph, on a minute-by-minute basis. In the laboratory, the VitaBit yielded specificity and negative predictive rates (NPR) of above 91.2% for sitting and standing, while sensitivity and precision ranged from 74.6% to 85.7%. For walking, all performance values exceeded 97.3%. In the free-living condition, the device revealed performance of over 72.6% for sitting with the ActiGraph as criterion. While sensitivity and precision for standing and walking ranged from 48.2% to 68.7%, specificity and NPR exceeded 83.9%. According to the laboratory findings, high performance for sitting, standing, and walking makes the VitaBit eligible for SB monitoring. As the results are not transferrable to daily life activities, a direct observation study in a free-living setting is recommended. PMID:29543766

Intermittent muscle activity in the feedback loop of postural control system during natural quiet standing.

PubMed

Tanabe, Hiroko; Fujii, Keisuke; Kouzaki, Motoki

2017-09-06

The origin of continual body oscillation during quiet standing is a neural-muscular-skeletal closed feedback loop system that includes insufficient joint stiffness and a time delay. Thus, muscle activity and joint oscillations are nonlinear during quiet standing, making it difficult to demonstrate the muscular-skeletal relationship experimentally. Here we experimentally revealed this relationship using intermittent control theory, in which non-actuation works to stabilize the skeletal system towards equilibrium. We found that leg muscles were activated/inactivated when the state point was located in the opposite/same direction as the direction of anatomical action, which was associated with joint torque actuating the body towards equilibrium. The derivative values of stability index defined in the phase space approximately 200 ms before muscle inactivation were also larger than those before activation for some muscles. These results indicate that bipedal standing might be achieved by monitoring the rate of change of stability/instability components and generating joint torque to stabilize the body. In conclusion, muscles are likely to activate in an event-driven manner during quiet standing and a possible metric for on/off switching is SI dot, and our methodology of EMG processing could allows us to extract such event-driven intermittent muscle activities.

Generation of double giant pulses in actively Q-switched lasers

NASA Astrophysics Data System (ADS)

Korobeynikova, A. P.; Shaikin, I. A.; Shaykin, A. A.; Koryukin, I. V.; Khazanov, E. A.

2018-04-01

Generation of a second giant pulse in a longitudinal mode neighbouring to the longitudinal mode possessing minimal losses is theoretically and experimentally studied in actively Q-switched lasers. A mathematical model is suggested for explaining the giant pulse generation in a laser with multiple longitudinal modes. The model makes allowance for not only a standing, but also a running wave for each cavity mode. Results of numerical simulation and data of experiments with a Nd : YLF laser explain the effect of second giant pulse generation in a neighbouring longitudinal mode. After a giant pulse in the mode with minimal losses is generated, the threshold for the neighbouring longitudinal mode is still exceeded due to the effect of burning holes in the population inversion spatial distribution.

Effect of species composition on carbon and nitrogen stocks in forest floor and mineral soil in Norway spruce and European beech mixed forests

NASA Astrophysics Data System (ADS)

Andivia, Enrique; Rolo, Víctor; Jonard, Mathieu; Formánek, Pavel; Ponette, Quentin

2015-04-01

Management of existing forests has been identified as the main strategy to enhance carbon sequestration and to mitigate the impact of climate change on forest ecosystems. In this direction, the conversion of Norway spruce monospecific stands into mixed stands by intermingling individuals of European beech is an ongoing trend in adaptive forest management strategies, especially in Central Europe. However, studies assessing the effect of changes in tree species composition on soil organic carbon (SOC) and nitrogen stocks are still scarce and there is a lack of scientific evidence supporting tree species selection as a feasible management option to mitigate the effects of predicted future climatic scenarios. We compared C and N stocks in the forest floor (litter and humus) and the top 10 cm of mineral soil in two monospecific stands of Norway spruce and European beech and in a mixed stand of both species. The effect of tree species composition on the C and N stocks and its spatial distribution was evaluated based on litterfall, root production, elevation and canopy opening, and by using a combination of modelling and geostatistical techniques. C stock was highest in the Norway spruce and the mixed stands, while N stock was highest in the mixed stand and lowest under European beech, with intermediate values in the Norway spruce stand. Each forest type showed differences in forest floor properties, suggesting that species composition is an important factor governing forest floor characteristics, including C and N stocks. The distribution of C and N stocks between forest soil layers was different for each forest type. C and N stocks were highest in the hummus layer under Norway spruce, whereas both stocks were lowest in the European beech stand. On the other hand, the mixed stand showed the highest C and N accumulation in the uppermost mineral soil layer, while the monospecific stands showed similar values. Litterfall was the main contribution to C and N stocks of the humus layer in monospecific stands. Forest floor stocks were also influenced by microelevation and canopy opening in the European beech stand and by microelevation in the Norway spruce stand. Root turnover and Norway spruce litterfall proportion directly increased C stocks in the mineral soil of the mixed stand. Additionally, N stock in the forest floor of the mixed stand was positively correlated with the Norway spruce litterfall proportion. Spatial analyses further confirmed that species composition was the main source of spatial variability of SOC stock in mixed stands. These results suggest that the admixture of individuals of European beech and Norway spruce may lead to a translocation of SOC from the forest floor to the better protected mineral soil layer, which might be beneficial for long term SOC sequestration.

Facile, Low-Cost, UV-Curing Approach to Prepare Highly Conductive Composites for Flexible Electronics Applications

NASA Astrophysics Data System (ADS)

Li, Fucheng; Chen, Shilong; Wei, Yong; Liu, Konghua; Lin, Yong; Liu, Lan

2016-07-01

We present a facile approach to prepare high-performance ultraviolet (UV)-curable polyurethane-acrylate-based flexible electrical conductive adhesive (PUA-FECA) for flexible electronics applications. PUA is employed as the polymer matrix so that the ECA is flexible and UV-curable at room temperature in just a few minutes. The effects of the PUA-FECA formulation and curing procedure on the electrical properties have been studied. Very low volume resistivity (5.08 × 10-4 Ω cm) is obtained by incorporating 70 wt.% microsized Ag-coated Cu flakes. Moreover, by simply standing the PUA-FECA paste for 4 h before exposure to UV light, the bulk resistivity of the PUA-FECA is dramatically decreased to 3.62 × 10-4 Ω cm. This can be attributed to rearrangement of Ag-coated Cu flakes in the matrix while standing. PUA-FECA also presents stable electrical conductivity during rolling and compression, excellent adhesion, and good processability, making it easily scalable to large-scale fabrication and enabling screen-printing on various low-cost flexible substrates such as office paper and polyethylene terephthalate film.

3D free-standing nitrogen-doped reduced graphene oxide aerogel as anode material for sodium ion batteries with enhanced sodium storage.

PubMed

Zhang, Jiao; Li, Chuanqi; Peng, Zhikun; Liu, Yushan; Zhang, Jianmin; Liu, Zhongyi; Li, Dan

2017-07-07

Sodium ion batteries have drawn extensive attentions for large-scale energy storage to replace lithium ion batteries primarily due to the natural abundance of sodium resource and low cost, but their energy density and electrochemical performance are hindered by the sluggish diffusion kinetics of sodium ion. Herein, free-standing nitrogen-doped graphene aerogel has been fabricated via hydrothermal reaction as the potential anode material for sodium ion batteries. The three dimensional porous network structure of the graphene aerogel provides sufficient interstitial space for sodium ion accommodation, allowing fast and reversible ion intercalation/de-intercalation. The nitrogen doping could introduce defects on the graphene sheets, making the feasible transport of large-sized sodium ion. Benefiting from the effective structure and nitrogen doping, the obtained material demonstrates high reversible capacities, good cycling performance (287.9 mA h g -1 after 200 cycles at a current density of 100 mA g -1 ), especially superior rate capability (151.9 mA h g -1 at a high current density of 5 A g -1 ).

Health technology assessment in India: the potential for improved healthcare decision-making.

PubMed

Kumar, Mrityunjai; Ebrahim, Shah; Taylor, Fiona C; Chokshi, Maulik; Gabbay, John

2014-01-01

Health technology assessment (HTA) is a multidisciplinary approach that uses clinical effectiveness, cost-effectiveness, policy and ethical perspectives to provide evidence upon which rational decisions on the use of health technologies can be made. It can be used for a single stand-alone technology (e.g. a drug, a device), complex interventions (e.g. a rehabilitation service) and can also be applied to individual patient care and to public health. It is a tool for enabling the assessment and comparison of health technologies using the same metric of cost-effectiveness. This process benefits the patient, the health service, the healthcare payer and the technology producer as only technologies that are considered cost-effective are promoted for widespread use. This leads to greater use of effective technologies and greater health gain. The decision-making process in healthcare in India is complex owing to multiplicity of organizations with overlapping mandates. Often the decision-making is not evidence-based and there is no mechanism of bridging the gap between evidence and policy. Elsewhere, HTA is a frequently used tool in informing policy decisions in both resource-rich and resource-poor countries. Despite national organizations producing large volumes of research and clinical guidelines, India has not yet introduced a formal HTA programme. The incremental growth in healthcare products, services, innovation in affordable medical devices and a move towards universal healthcare, needs to be underpinned with an evidencebase which focuses on effectiveness, safety, affordability and acceptability to maximize the benefits that can be gained with a limited healthcare budget. Establishing HTA as a formal process in India, independent of healthcare providers, funders and technology producers, together with a framework for linking HTA to policy-making, would help ensure that the population gets better access to appropriate healthcare in the future. Copyright 2014, NMJI.

The Enigma of Mercury's Northern Rise

NASA Astrophysics Data System (ADS)

James, P. B.

2018-05-01

Various aspects of the "northern rise" make it hard to explain: Its composition and chronology don't stand out from its surroundings, it seems to have uplifted late, and it has a huge gravity anomaly. We'll discuss the possible formation mechanisms.

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.

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.

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.

Improving efficiency of a regional stand alone bone bank.

PubMed

Warnock, Jonathan M; Rowan, Clare H; Davidson, Helen; Millar, Ciara; McAlinden, M Gavan

2016-03-01

The introduction of a stand-alone Bone Bank in our Regional Orthopaedic Hospital has improved the availability of femoral head allograft. Benninger et al. (Bone Joint J 96-B:1307-1311, 2014), demonstrated their institutions bank to be cost effective despite a 30 % discard rate for harvested allograft. We sought to audit our own discard rates and subsequent cost-effectiveness of our bone bank. Donor recruitment. Before approaching a potential donor, our establishment's nurse specialists review their clinical notes and biochemical laboratory results, available on a regional Electronic Care Records. They view femoral head architecture on radiographs against set criteria, Patient Archive and Communication system (SECTRA, Sweden). In total 1383 femoral heads were harvested, 247 were discarded giving an overall rate of 17.9 %. The most common reasons for discard of harvested graft was a positive microbiology/bacteriology result, n = 96 (38.9 %). After a rise in discard rates in 2007, we have steadily reduced our discard rates since 2006/2007 (28.2 %), 2008/2009 (17 %), 2010/2011 (14.8 %), and finally to 10.3 % in 2012/2013. In the current financial year, our cost to harvest, test, store and release a femoral head is £ 610. With a structured donor recruitment process and unique pre-operative radiographic analysis we have successfully reduced our discard rates bi-annually making our bone bank increasingly cost-effective.

Effects of timber harvesting on coarse woody debris in red pine forets across the Great Lakes states, U.S.A.

Treesearch

Matthew D. Duvall; David F. Grigal

1999-01-01

Coarse woody debris (CWD) chronosequences were developed for managed and unmanaged red pine (Pinus resinosa Ait.) stands across the Great Lakes states. Throughout stand development, there is less CWD in managed than in unmanaged forests, and effects of management are strongest in young forests (0-30 years old). At stand initiation, CWD is 80% lower in managed than...

The Effect Of Age At Harvest On Bending And Tensile Properties Of Loblolly Pine From The Coastal Plain

Treesearch

Robert H. McAlister; Alexander Clark; Joseph R. Saucier

1997-01-01

The effect of rotation age on strength and stiffness of lumber produced from unthinned loblolly pine stands in the Coastal Plain of Georgia was examined. Six stands representing 22-, 28-, and 40-year-old roations were sampled. A stratified random sample of trees 8 to 16 inches in diameter at breast height was selected from each stand and processed into lumber....

Effects of height and live crown ratio imputation strategies on stand biomass estimation

Treesearch

Elijah J. Allensworth; Temesgen. Hailemariam

2015-01-01

The effects of subsample design and imputation of total height (ht) and live crown ratio (cr) on the accuracy of stand-level estimates of component and total aboveground biomass are not well investigated in the current body of literature. To assess this gap in research, this study uses a data set of 3,454 Douglas-fir trees obtained from 102 stands in southwestern...

Evaluation of a Silver-Embedded Ceramic Tablet as a Primary and Secondary Point-of-Use Water Purification Technology in Limpopo Province, S. Africa

PubMed Central

Ehdaie, Beeta; Rento, Chloe T.; Son, Veronica; Turner, Sydney S.; Samie, Amidou; Dillingham, Rebecca A.

2017-01-01

The World Health Organization (WHO) recognizes point-of-use water treatment (PoUWT) technologies as effective means to improve water quality. This paper investigates long-term performance and social acceptance of a novel PoUWT technology, a silver-infused ceramic tablet, in Limpopo Province, South Africa. When placed in a water storage container, the silver-embedded ceramic tablet releases silver ions into water, thereby disinfecting microbial pathogens and leaving the water safe for human consumption. As a result of its simplicity and efficiency, the silver-embedded ceramic tablet can serve as a stand-alone PoUWT method and as a secondary PoUWT to improve exisitng PoUWT methods, such as ceramic water filters. In this paper, three PoUWT interventions were conducted to evaluate the silver-embedded ceramic tablet: (1) the silver-embedded ceramic tablet as a stand-alone PoUWT method, (2) ceramic water filters stand-alone, and (3) a filter-tablet combination. The filter-tablet combination evaluates the silver-embedded ceramic tablet as a secondary PoUWT method when placed in the lower reservoir of the ceramic water filter system to provide residual disinfection post-filtration. Samples were collected from 79 households over one year and analyzed for turbidity, total silver levels and coliform bacteria. Results show that the silver-embedded ceramic tablet effectively reduced total coliform bacteria (TC) and E. coli when used as a stand-alone PoUWT method and when used in combination with ceramic water filters. The silver-embedded ceramic tablet’s performance as a stand-alone PoUWT method was comparable to current inexpensive, single-use PoUWT methods, demonstrating 100% and 75% median reduction in E. coli and TC, respectively, after two months of use. Overall, the the filter-tablet combination performed the best of the three interventions, providing a 100% average percent reduction in E. coli over one year. User surveys were also conducted and indicated that the silver-embedded ceramic tablet was simple to use and culturally appropriate. Also, silver levels in all treated water samples remained below 20 μg/L, significantly lower than the drinking water standard of 100 μg/L, making it safe for consumption. Long-term data demonstrates that the silver-embedded ceramic tablet has beneficial effects even after one year of use. This study demonstrates that the silver-embedded ceramic tablet can effectively improve water quality when used alone, or with ceramic water filters, to reduce rates of recontamination. Therefore, the tablet has the potential to provide a low-cost means to purify water in resource-limited settings. PMID:28095435

Evaluation of a Silver-Embedded Ceramic Tablet as a Primary and Secondary Point-of-Use Water Purification Technology in Limpopo Province, S. Africa.

PubMed

Ehdaie, Beeta; Rento, Chloe T; Son, Veronica; Turner, Sydney S; Samie, Amidou; Dillingham, Rebecca A; Smith, James A

2017-01-01

The World Health Organization (WHO) recognizes point-of-use water treatment (PoUWT) technologies as effective means to improve water quality. This paper investigates long-term performance and social acceptance of a novel PoUWT technology, a silver-infused ceramic tablet, in Limpopo Province, South Africa. When placed in a water storage container, the silver-embedded ceramic tablet releases silver ions into water, thereby disinfecting microbial pathogens and leaving the water safe for human consumption. As a result of its simplicity and efficiency, the silver-embedded ceramic tablet can serve as a stand-alone PoUWT method and as a secondary PoUWT to improve exisitng PoUWT methods, such as ceramic water filters. In this paper, three PoUWT interventions were conducted to evaluate the silver-embedded ceramic tablet: (1) the silver-embedded ceramic tablet as a stand-alone PoUWT method, (2) ceramic water filters stand-alone, and (3) a filter-tablet combination. The filter-tablet combination evaluates the silver-embedded ceramic tablet as a secondary PoUWT method when placed in the lower reservoir of the ceramic water filter system to provide residual disinfection post-filtration. Samples were collected from 79 households over one year and analyzed for turbidity, total silver levels and coliform bacteria. Results show that the silver-embedded ceramic tablet effectively reduced total coliform bacteria (TC) and E. coli when used as a stand-alone PoUWT method and when used in combination with ceramic water filters. The silver-embedded ceramic tablet's performance as a stand-alone PoUWT method was comparable to current inexpensive, single-use PoUWT methods, demonstrating 100% and 75% median reduction in E. coli and TC, respectively, after two months of use. Overall, the the filter-tablet combination performed the best of the three interventions, providing a 100% average percent reduction in E. coli over one year. User surveys were also conducted and indicated that the silver-embedded ceramic tablet was simple to use and culturally appropriate. Also, silver levels in all treated water samples remained below 20 μg/L, significantly lower than the drinking water standard of 100 μg/L, making it safe for consumption. Long-term data demonstrates that the silver-embedded ceramic tablet has beneficial effects even after one year of use. This study demonstrates that the silver-embedded ceramic tablet can effectively improve water quality when used alone, or with ceramic water filters, to reduce rates of recontamination. Therefore, the tablet has the potential to provide a low-cost means to purify water in resource-limited settings.

Substitutional carbon doping of free-standing and Ru-supported BN sheets: a first-principles study

NASA Astrophysics Data System (ADS)

Berseneva, N.; Komsa, H.-P.; Vierimaa, V.; Björkman, T.; Fan, Z.; Harju, A.; Todorović, M.; Krasheninnikov, A. V.; Nieminen, R. M.

2017-10-01

The development of spatially homogeneous mixed structures with boron (B), nitrogen (N) and carbon (C) atoms arranged in a honeycomb lattice is highly desirable, as they open the possibility of creating stable two-dimensional materials with tunable band gaps. However, at least in the free-standing form, the mixed BCN system is energetically driven towards phase segregation to graphene and hexagonal BN. It is possible to overcome the segregation when BCN material is grown on a particular metal substrate, for example Ru(0 0 0 1), but the stabilization mechanism is still unknown. With the use of density-functional theory we study the energetics of BN/Ru slabs, with different types of configurations of C substitutional defects introduced to the h-BN overlayer. The results are compared to the energetics of free-standing BCN materials. We found that the substrate facilitates the C substitution process in the h-BN overlayer. Thus, more homogeneous BCN material can be grown, overcoming the segregation into graphene and h-BN. In addition, we investigate the electronic and transport gaps in free-standing BCN structures, and assess their mechanical properties and stability. The band gap in mixed BCN free-standing material depends on the concentration of the constituent elements and ranges from zero in pristine graphene to nearly 5 eV in free-standing h-BN. This makes BCN attractive for application in modern electronics.

Site preparation burning to improve southern Appalachian pine-hardwood stands: vegetation composition and diversity of 13-year-old stands

Treesearch

Barton D. Clinton; J.M. Vose; W.T. Swank

1993-01-01

Stand restoration of low-quality, mixed pine-hardwood ecosystems containing a Kalmia Zatifolia L. dominated understory, through cutting, burning, and planting of Pinus strobus L., is common on xeric southern Appalachian forest sites. We examined the effects of this treatment on early vegetation composition and diversity. Four 13-year-old stands were examined. Two of...

The Effect of Cycling Intensity on Cycling Economy During Seated and Standing Cycling.

PubMed

Arkesteijn, Marco; Jobson, Simon; Hopker, James; Passfield, Louis

2016-10-01

Previous research has shown that cycling in a standing position reduces cycling economy compared with seated cycling. It is unknown whether the cycling intensity moderates the reduction in cycling economy while standing. The aim was to determine whether the negative effect of standing on cycling economy would be decreased at a higher intensity. Ten cyclists cycled in 8 different conditions. Each condition was either at an intensity of 50% or 70% of maximal aerobic power at a gradient of 4% or 8% and in the seated or standing cycling position. Cycling economy and muscle activation level of 8 leg muscles were recorded. There was an interaction between cycling intensity and position for cycling economy (P = .03), the overall activation of the leg muscles (P = .02), and the activation of the lower leg muscles (P = .05). The interaction showed decreased cycling economy when standing compared with seated cycling, but the difference was reduced at higher intensity. The overall activation of the leg muscles and the lower leg muscles, respectively, increased and decreased, but the differences between standing and seated cycling were reduced at higher intensity. Cycling economy was lower during standing cycling than seated cycling, but the difference in economy diminishes when cycling intensity increases. Activation of the lower leg muscles did not explain the lower cycling economy while standing. The increased overall activation, therefore, suggests that increased activation of the upper leg muscles explains part of the lower cycling economy while standing.

Changes in fire intensity have carry-over effects on plant responses after the next fire in southern California chaparral

USGS Publications Warehouse

Moreno, Jose M.; Torres, Ivan; Luna, Belen; Oechel, Walter C.; Keeley, Jon E.

2013-01-01

QuestionDo variations in fire intensity within a stand determine changes in fire intensity and plant demographics in a subsequent fire?LocationSan Diego (CA, USA); chaparral dominated by Adenostoma fasciculatum (resprouter) and Ceanothus greggii (seeder).MethodsIn 2003, a wildfire burned a young (16-yr-old) stand containing a set of experimental plots burned in 1987 with various levels of fire intensity. In 2004, all the 1987 plots were sampled for Adenostoma survival and the recruitment of both species. Similar measures were carried out in the adjacent old (75-yr) stand. Fire intensity in 2003 was estimated by a surrogate fire severity measure [minimum diameter of burned branches (branch diameter)].ResultsIn the young stand, branch diameter in 2003 was similar to the control plots in 1987, but lower than in the old stand. Fire intensity in 1987 did not significantly affect branch diameter in 2003. Survival of Adenostoma in the young stand was very low, much lower than after the 1987 burn and that in the old stand. Fire intensity in 1987 did not affect Adenostoma survival. Recruitment in Adenostoma increased, and in Ceanothus decreased, with increased fire intensity in 1987.ConclusionsWe demonstrate that there is a carry-over effect of fire intensity across a whole fire cycle on plant recruitment of the two dominant species. The 2003 fire partially reversed the relative effects on recruitment caused by elevated fire intensity in 1987. Arguably, this effect was driven by the contrasted relationships of the two species to fire intensity. Adenostoma survival in the young stand was much lower in 2003 than in 1987, despite similar branch diameter, and was also lower than in the old stand, despite higher branch diameter in this case. The causes of such mortality are unknown.

Child-Witnessed Domestic Violence and its Adverse Effects on Brain Development: A Call for Societal Self-Examination and Awareness

PubMed Central

Tsavoussis, Areti; Stawicki, Stanislaw P. A.; Stoicea, Nicoleta; Papadimos, Thomas J.

2014-01-01

There is substantial evidence indicating that children who witness domestic violence (DV) have psychosocial maladaptation that is associated with demonstrable changes in the anatomic and physiological make up of their central nervous system. Individuals with these changes do not function well in society and present communities with serious medical, sociological, and economic dilemmas. In this focused perspective, we discuss the psychosocially induced biological alterations (midbrain, cerebral cortex, limbic system, corpus callosum, cerebellum, and the hypothalamic, pituitary, and adrenal axis) that are related to maladaptation (especially post-traumatic stress disorder) in the context of child-witnessed DV, and provide evidence for these physical alterations to the brain. Herein, we hope to stimulate the necessary political discourse to encourage legal systems around the world to make the act of DV in the presence of a child, including a first time act, a stand-alone felony. PMID:25346927

Optical Magnetometry using Multipass Cells with overlapping beams

NASA Astrophysics Data System (ADS)

McDonough, Nathaniel David; Lucivero, Vito Giovanni; Dural, Nezih; Romalis, Michael

2017-04-01

In recent years, multipass cells with cylindrical mirrors have proven to be a successful way of making highly sensitive atomic magnetometers. In such cells a small laser beam makes 40 to 100 passes within the cell without significant overlap with itself. Here we describe a new multi-pass geometry which uses spherical mirrors to reflect the probe beam multiple times over the same cell region. Such geometry reduces the effects of atomic diffusion while preserving the advantages of multi-pass cells over standing-wave cavities, namely a deterministic number of passes and absence of interference. We have fabricated several cells with this geometry and obtained good agreement between the measured and calculated levels of quantum spin noise. We will report on our effort to characterize the diffusion spin-correlation function in these cells and operation of the cell as a magnetometer. This work is supported by DARPA.

Men seek social standing, women seek companionship: sex differences in deriving self-worth from relationships.

PubMed

Kwang, Tracy; Crockett, Erin E; Sanchez, Diana T; Swann, William B

2013-07-01

Do men base their self-worth on relationships less than do women? In an assessment of lay beliefs, men and women alike indicated that men are less reliant on relationships as a source of self-worth than are women (Study 1). Yet relationships may make a different important contribution to the self-esteem of men. Men reported basing their self-esteem on their own relationship status (whether or not they were in a relationship) more than did women, and this link was statistically mediated by the perceived importance of relationships as a source of social standing (Studies 1 and 2). Finally, when relationship status was threatened, men displayed increased social-standing concerns, whereas women displayed increased interdependence concerns (Study 3). Together, these findings demonstrate that both men and women rely on relationships for self-worth, but that they derive self-esteem from relationships in different ways.

Effects of postfire salvage logging on deadwood-associated beetles.

PubMed

Cobb, T P; Morissette, J L; Jacobs, J M; Koivula, M J; Spence, J R; Langor, D W

2011-02-01

In Canada and the United States pressure to recoup financial costs of wildfire by harvesting burned timber is increasing, despite insufficient understanding of the ecological consequences of postfire salvage logging. We compared the species richness and composition of deadwood-associated beetle assemblages among undisturbed, recently burned, logged, and salvage-logged, boreal, mixed-wood stands. Species richness was lowest in salvage-logged stands, largely due to a negative effect of harvesting on the occurrence of wood- and bark-boring species. In comparison with undisturbed stands, the combination of wildfire and logging in salvage-logged stands had a greater effect on species composition than either disturbance alone. Strong differences in species composition among stand treatments were linked to differences in quantity and quality (e.g., decay stage) of coarse woody debris. We found that the effects of wildfire and logging on deadwood-associated beetles were synergistic, such that the effects of postfire salvage logging could not be predicted reliably on the basis of data on either disturbance alone. Thus, increases in salvage logging of burned forests may have serious negative consequences for deadwood-associated beetles and their ecological functions in early postfire successional forests. ©2010 Society for Conservation Biology.

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

Zarnoch, Stanley J.; Blake, John I.; Parresol, Bernard R.

Snags are standing dead trees that are an important component in the nesting habitat of birds and other species. Although snag availability is believed to limit populations in managed and non-managed forests, little data are available to evaluate the relative effect of stand conditions and management on snag occurrence. We analyzed point sample data from an intensive forest inventory within an 80,000 ha landscape for four major forest types to support the hypotheses that routine low-intensity prescribed fire would increase, and thinning would decrease, snag occurrence. We employed path analysis to define a priori causal relationships to determine the directmore » and indirect effects of site quality, age, relative stand density index and fire for all forest types and thinning effects for loblolly pine and longleaf pine. Stand age was an important direct effect for loblolly pine, mixed pine-hardwoods and hardwoods, but not for longleaf pine. Snag occurrence in loblolly pine was increased by prescribed fire and decreased by thinning which confirmed our initial hypotheses. Although fire was not important in mixed pine-hardwoods, it was for hardwoods but the relationship depended on site quality. For longleaf pine the relative stand density index was the dominant variable affecting snag occurrence, which increased as the density index decreased. Site quality, age and thinning had significant indirect effects on snag occurrence in longleaf pine through their effects on the density index. Although age is an important condition affecting snag occurrence for most forest types, path analysis revealed that fire and density management practices within certain forest types can also have major beneficial effects, particularly in stands less than 60 years old.« less

Experimental observation of standing wave effect in low-pressure very-high-frequency capacitive discharges

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

Liu, Yong-Xin; Gao, Fei; Liu, Jia

2014-07-28

Radial uniformity measurements of plasma density were carried out by using a floating double probe in a cylindrical (21 cm in electrode diameter) capacitive discharge reactor driven over a wide range of frequencies (27–220 MHz). At low rf power, a multiple-node structure of standing wave effect was observed at 130 MHz. The secondary density peak caused by the standing wave effect became pronounced and shifts toward the axis as the driving frequency further to increase, indicative of a much more shortened standing-wave wavelength. With increasing rf power, the secondary density peak shift toward the radial edge, namely, the standing-wave wavelength was increased,more » in good qualitative agreement with the previous theory and simulation results. At higher pressures and high frequencies, the rf power was primarily deposited at the periphery of the electrode, due to the fact that the waves were strongly damped as they propagated from the discharge edge into the center.« less

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.

Must Children Testify in Grown-Up Courtrooms?

ERIC Educational Resources Information Center

Myers, John E. B.

1993-01-01

The demands of the American justice system make testimony difficult for children, yet the presumption of innocence and the rights of the accused are so important that society is justified in asking even young children to endure the stress of the witness stand. (MDM)

s09-48-3139

NASA Image and Video Library

2009-06-25

STS009-48-3139 (28 Nov-8 Dec 1983) --- Canada (Quebec) the contrast between forest, water, and snow make the Manicouagane impact formation stand out. Location: 150 miles (250 Km) NNW of Sept Iles or 500 miles (800 Km) NNE of Montreal on the Canadian Shield.

Making Mathematics.

ERIC Educational Resources Information Center

Huckstep, Peter

2002-01-01

Contends teachers must resist the temptation to suggest that, while children can create stories and melodies, they cannot create mathematics. Quotes mathematician G. H. Hardy: "A mathematician, like a painter or poet, is a 'maker' of patterns." Considers mathematics should be able to stand up for itself. (BT)

Examining Cyber Command Structures

DTIC Science & Technology

2015-03-01

domains, cyber, command and control, USCYBERCOM, combatant command, cyber force PAGES 65 16. PRICE CODE 17. SECURITY 18. SECURITY 19. SECURITY 20...USCYBERCOM, argue for the creation of a stand-alone cyber force.11 They claim that the military’s tradition-oriented and inelastic nature make the

High-speed coronary rotational angioplasty with the rotablator

NASA Astrophysics Data System (ADS)

Zacca, Nadim M.; Kleiman, Neal S.; Asimacopoulos, P. J.

1992-08-01

Percutaneous mechanical rotational ablation with the rotablator can be used effectively as a stand alone treatment for coronary arterial lesions, including those with angiographic morphology considered unfavorable for balloon angioplasty (eccentric, at bends, bifurcating, calcified, ulcerated, completely occluded_, as well as for balloon angioplasty procedure failures. The use of single rather than multiple burrs without balloon assistance, the use of fewer passes and of the nitroglycerine infusion through the rotablator catheter have considerably shortened the time necessary to complete a rotational atherectomy. Further, the apparently infrequent occurrence of post procedure abrupt closure makes this technique attractive in the clinical management of patients with complex coronary artery lesions.

Risk attitudes and birth order.

PubMed

Krause, Philipp; Heindl, Johannes; Jung, Andreas; Langguth, Berthold; Hajak, Göran; Sand, Philipp G

2014-07-01

Risk attitudes play important roles in health behavior and everyday decision making. It is unclear, however, whether these attitudes can be predicted from birth order. We investigated 200 mostly male volunteers from two distinct settings. After correcting for multiple comparisons, for the number of siblings and for confounding by gender, ordinal position predicted perception of health-related risks among participants in extreme sports (p < .01). However, the direction of the effect contradicted Adlerian theory. Except for alcohol consumption, these findings extended to self-reported risk behavior. Together, the data call for a cautious stand on the impact of birth order on risk attitudes. © The Author(s) 2013.

Quantum enhancement of momentum diffusion in the delta-kicked rotor.

PubMed

d'Arcy, M B; Godun, R M; Oberthaler, M K; Cassettari, D; Summy, G S

2001-08-13

We present detailed observations of the quantum delta-kicked rotor in the vicinity of a quantum resonance. Our experiment consists of an ensemble of cold cesium atoms subject to a pulsed off-resonant standing wave of light. We measure the mean energy and show clearly that at the quantum resonance it is a local maximum. We also examine the effect of noise on the system and find that the greatest sensitivity to this occurs at the resonances. This makes these regions ideal for examining quantum-classical correspondence. A picture based on diffraction is developed which allows the experiments to be readily understood.

Effect of time elapsed after prescribed burning in longleaf pine stands on potential prey of the red-cockaded woodpecker

Treesearch

Kirsten C. New; James L. Hanula

1998-01-01

The effects of dormant and growing season prescribed burns on the potential arthropod prey of the red-cockaded woodpecker (Picoides borealis) were studied in longleaf pine (Pinus palustris Mill.) stands on the upper Coastal Plain of South Carolina. Sampling was conducted 0, 1, 2, or 3 years post burn. Stands were burned once during the winters of 1991, 1992, 1993, and...

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...

Long-term (13-year) effects of repeated prescribed fires on stand structure and tree regeneration in mixed-oak forests

Treesearch

Todd F. Hutchinson; Daniel A. Yaussy; Robert P. Long; Joanne Rebbeck; Elaine Kennedy. Sutherland

2012-01-01

The survival and growth of oak advance regeneration is often limited by shade-tolerant species that are abundant in the understory of oak stands. Evidence of historic burning has prompted the use of prescribed fire as a tool to improve the competitive status of oak regeneration in mature stands. A primary shortfall of fire effects research in oak forests has been a...

Seed Production in Southern Appalachian Oak Stands

Treesearch

Donald E. Beck; David F. Olson

1968-01-01

Acorn production in mixed oak stands of different densities varied considerably among stands, years, and species. Density had no effect on total acorn production. Although numerous acorns were initiated each year, the majority either failed to develop fully or were damaged by insects and animals.

Reducing Office Workers' Sitting Time at Work Using Sit-Stand Protocols: Results From a Pilot Randomized Controlled Trial.

PubMed

Li, Ingrid; Mackey, Martin G; Foley, Bridget; Pappas, Evangelos; Edwards, Kate; Chau, Josephine Y; Engelen, Lina; Voukelatos, Alexander; Whelan, Anna; Bauman, Adrian; Winkler, Elisabeth; Stamatakis, Emmanuel

2017-06-01

To examine the effects of different sit-stand protocols on work-time sitting and physical activity (PA) of office workers. Participants (n = 26, 77% women, mean age 42) were randomly allocated to usual sitting (control) or one of three sit-stand protocols (intervention) facilitated by height-adjustable workstations for a 4-week period between June and August 2015. Sitting, standing, and stepping time were assessed by inclinometry (activPAL); leisure-time physical activity (LTPA) by self-report. One-way analysis of covariance (ANCOVA) and post-hoc (Bonferroni) tests explored between-group differences. Compared with baseline, intervention groups reduced work sitting time by 113 minutes/8-hour workday (95% confidence interval [CI] [-147,-79]) and increased work standing time by 96 minutes/8-hour workday (95% CI [67,125]) without significantly impacting LTPA/sleep time. Sit-stand protocols facilitated by height-adjustable workstations appear to reduce office workers' sitting time without significant adverse effects on LTPA.

Stand Structure and Composition 32 Years after Precommercial Thinning Treatments in a Mixed Northern Conifer Stand in Central Maine

Treesearch

Aaron R. Weiskittel; Laura S. Kenefic; Rongxia Li; John Brissette

2011-01-01

The effects of four precommercial thinning (PCT) treatments on an even-aged northern conifer stand in Maine were investigated by examining stand structure and composition 32 years after treatment. Replicated treatments applied in 1976 included: (1) control (no PCT), (2) row thinning (rowthin; 5-ft-wide row removal with 3-ft-wide residual strips), (3) row thinning with...

Experience with the selection method in pine stands in the southern United States, with implications for future application

Treesearch

James M. Guldin

2011-01-01

The selection method applied in shade-intolerant pine stands in the southern United States has been shown to be an effective method of uneven-aged silviculture, but it is becoming less frequently practiced for a variety of reasons. Economically, the high value of standing timber puts fully stocked uneven-aged pine stands at risk of liquidation if the timberland is sold...

Long-term development of regeneration under longleaf pine seedtree and shelterwood stands

Treesearch

William D. Boyer

1993-01-01

Well-stocked mature longleaf pine (Pinus palustris Mill.) stands were cut tofive residual basal areas in 1957, namely 9,18,2 7.36, and 45 ft2 per ac, to observe the effect of stand density on seed production and seedling establishment. Seedlings, mainly from the 195.5 or 1961 seed crops, were established in treated stands. All pines on net 0.9 ac...

Comparison of terrestrial invertebrate biomass and richness in young mixed red alder-conifer, young conifer, and old conifer stands of southeast Alaska.

Treesearch

Mark E. Schultz; Toni L. De Santo

2008-01-01

Coniferous stands that regenerate following clearcutting in southeast Alaska can be characterized by the amount of soil disturbance during logging. There are indications that red alder in mixed stands mitigates some of the negative effects of clearcutting. We compared invertebrate biomass in four stands each of (1) young conifers, (2) young mixed alder and conifer, and...

The effects of standing, lifting and noise exposure on preterm birth, growth restriction, and perinatal death in healthy low-risk working military women.

PubMed

Magann, Everett F; Evans, Sharon F; Chauhan, Suneet P; Nolan, Thomas E; Henderson, Jenni; Klausen, Jack H; Newnham, John P; Morrison, John C

2005-09-01

The effects of standing, lifting and noise in low-risk, healthy pregnant women are uncertain. In the past, the heterogeneity of the populations studied, the limitations of the designs of the retrospective and case control studies, and a failure of some of the larger investigations to evaluate all the potential confounding variables has hampered many studies. The purpose of this investigation was to evaluate, throughout pregnancy, the effects of standing, repetitive lifting, and noise in the workplace compared with no standing, lifting or noise exposure, on maternal and perinatal outcomes in a large prospective study of a low-risk healthy population of working women cared for by a single group of health providers. This prospective observational study used an extensive questionnaire to collect antepartum, intrapartum, and postpartum information. Information was collected on the initial visit, each subsequent visit, and immediately after delivery. The participating women were divided into groups based on the amount of time spent standing, the amount and extent of repetitive lifting, and noise exposure in the workplace. Eight hundred and fourteen low-risk active duty women participated in this investigation over a 4-year period. Multivariate analysis with non-exposure compared with exposure reinforced the effect of standing on preterm labor (OR 1.80, 95% CI 1.05, 3.16) and preterm birth (OR 1.69, 95% CI 1.03, 2.80) and showed a trend toward an effect of noise exposure on preterm labor (OR 1.76, 95% CI 0.78, 3.39) after controlling for other exposures. This investigation suggests an association of occupational standing with preterm labor and preterm birth.

The effect of different unstable footwear constructions on centre of pressure motion during standing.

PubMed

Plom, W; Strike, S C; Taylor, M J D

2014-06-01

The aim of this study was to test the effect different unstable footwear constructions have on centre of pressure motion when standing. Sixteen young female volunteers were tested in five conditions, three unstable footwear (Reebok Easy-Tone, FitFlop and Skechers Shape-Ups), a standard shoe and barefoot in a randomised order. Double and single leg balance on a force plate was assessed via centre of pressure excursions and displacements in each condition. For double leg and single leg standing centre of pressure excursions in the anterior-posterior direction were significantly increased wearing Skechers Shape-Ups compared to barefoot and the standard shoe. For the Reebok Easy Tone during single leg standing excursions in the anterior-posterior direction were significantly greater compared to the barefoot condition. Cumulative displacement of the centre of pressure in medial-lateral direction increased significantly during single leg standing when wearing Skechers Shape-Ups compared to barefoot and standard shoe as well as for Reebok Easy Tone vs. barefoot. It would appear from these quiet standing results that the manner of the construction of instability shoes effects the CoP movement which is associated with induced instability. Greater CoP excursion occurred in the A-P direction while the cumulative displacements were greater in the M-L direction for those shoes with the rounded sole and soft foam and those with airpods. The shoe construction with altered density foam did not induce any change in the CoP movement, during quite standing, which tends to suggest that it is not effective at inducing balance. Not all instability shoes are effective in altering the overall instability of the wearer. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Extended self-ordering regime in hard anodization and its application to make asymmetric AAO membranes for large pitch-distance nanostructures.

PubMed

Kim, Minwoo; Ha, Yoon-Cheol; Nguyen, Truong Nhat; Choi, Hae Young; Kim, Doohun

2013-12-20

We report here a fast and reliable hard anodization process to make asymmetric anodic aluminum oxide (AAO) membranes which can serve as a template for large pitch-distance nanostructures. In order to make larger pitch distances possible, the common burning failure associated with the high current density during the conventional constant voltage hard anodization, especially at a voltage higher than a known limit, i.e., 155 V for oxalic acid, was effectively suppressed by using a burning-protective agent. A new self-ordering regime beyond the voltage limit was observed with a different voltage-interpore distance relationship of 2.2 nm V(-1) compared to the reported 2.0 nm V(-1) for hard anodization. Combining a sulfuric acid mild anodization with this new regime of hard anodization, we further demonstrate a scalable process to make an asymmetric membrane with size up to ~47 mm in diameter and ~60 μm in thickness. This free-standing membrane can be used as a template for novel nanopatterned structures such as arrays of quantum dots, nanowires or nanotubes with diameters of a few tens of nanometers and pitch distance of over 400 nm.

Extended self-ordering regime in hard anodization and its application to make asymmetric AAO membranes for large pitch-distance nanostructures

NASA Astrophysics Data System (ADS)

Kim, Minwoo; Ha, Yoon-Cheol; Nhat Nguyen, Truong; Choi, Hae Young; Kim, Doohun

2013-12-01

We report here a fast and reliable hard anodization process to make asymmetric anodic aluminum oxide (AAO) membranes which can serve as a template for large pitch-distance nanostructures. In order to make larger pitch distances possible, the common burning failure associated with the high current density during the conventional constant voltage hard anodization, especially at a voltage higher than a known limit, i.e., 155 V for oxalic acid, was effectively suppressed by using a burning-protective agent. A new self-ordering regime beyond the voltage limit was observed with a different voltage-interpore distance relationship of 2.2 nm V-1 compared to the reported 2.0 nm V-1 for hard anodization. Combining a sulfuric acid mild anodization with this new regime of hard anodization, we further demonstrate a scalable process to make an asymmetric membrane with size up to ˜47 mm in diameter and ˜60 μm in thickness. This free-standing membrane can be used as a template for novel nanopatterned structures such as arrays of quantum dots, nanowires or nanotubes with diameters of a few tens of nanometers and pitch distance of over 400 nm.

Standing with electrical stimulation and splinting is no better than standing alone for management of ankle plantarflexion contractures in people with traumatic brain injury: a randomised trial.

PubMed

Leung, Joan; Harvey, Lisa A; Moseley, Anne M; Whiteside, Bhavini; Simpson, Melissa; Stroud, Katarina

2014-12-01

Is a combination of standing, electrical stimulation and splinting more effective than standing alone for the management of ankle contractures after severe brain injury? A multi-centre randomised trial with concealed allocation, assessor blinding and intention-to-treat analysis. Thirty-six adults with severe traumatic brain injury and ankle plantarflexion contractures. All participants underwent a 6-week program. The experimental group received tilt table standing, electrical stimulation and ankle splinting. The control group received tilt table standing alone. The primary outcome was passive ankle dorsiflexion with a 12Nm torque. Secondary outcomes included: passive dorsiflexion with lower torques (3, 5, 7 and 9Nm); spasticity; the walking item of the Functional Independence Measure; walking speed; global perceived effect of treatment; and perceived treatment credibility. OUTCOME MEASURES were taken at baseline (Week 0), end of intervention (Week 6), and follow-up (Week 10). The mean between-group differences (95% CI) for passive ankle dorsiflexion at Week 6 and Week 10 were -3 degrees (-8 to 2) and -1 degrees (-6 to 4), respectively, in favour of the control group. There was a small mean reduction of 1 point in spasticity at Week 6 (95% CI 0.1 to 1.8) in favour of the experimental group, but this effect disappeared at Week 10. There were no differences for other secondary outcome measures except the physiotherapists' perceived treatment credibility. Tilt table standing with electrical stimulation and splinting is not better than tilt table standing alone for the management of ankle contractures after severe brain injury. ACTRN12608000637347. [Leung J, Harvey LA, Moseley AM, Whiteside B, Simpson M, Stroud K (2014) Standing with electrical stimulation and splinting is no better than standing alone for management of ankle plantarflexion contractures in people with traumatic brain injury: a randomised trial.Journal of Physiotherapy60: 201-208]. Copyright © 2014 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Effects of Stocking Rate on the Variability of Peak Standing Crop in a Desert Steppe of Eurasia Grassland

NASA Astrophysics Data System (ADS)

Wang, Zhongwu; Jiao, Shuying; Han, Guodong; Zhao, Mengli; Ding, Haijun; Zhang, Xinjie; Wang, Xiaoliang; Ayers, Eldon L.; Willms, Walter D.; Havsatad, Kris; A, Lata; Liu, Yongzhi

2014-02-01

Proper grazing management practices can generate corresponding compensatory effects on plant community production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how grazing influences plant community attributes and the variability of standing crop. We examined the effects of sheep grazing at four stocking rate treatments [control, 0 sheep ha-1 month-1; light (LG), 0.15 sheep ha-1 month-1; moderate (MG), 0.30 sheep ha-1 month-1; and heavy (HG), 0.45 sheep ha-1 month-1] on standing crop at the community level and partitioned by species and functional groups, in the desert steppe of Inner Mongolia, China. The treatments were arranged in a completely randomized block design over a 9-year period. Standing crop was measured every August from 2004 to 2012. Peak standing crop decreased ( P < 0.05) with increasing stocking rate; peak standing crop in the HG treatment decreased 40 % compared to the control. May-July precipitation explained at least 76 % of the variation in peak standing crop. MG and HG treatments resulted in a decrease ( P < 0.05) in shrubs, semi-shrubs, and perennials forbs, and an increase ( P < 0.05) in perennial bunchgrasses compared to the control. The coefficients of variation at plant functional group and species level in the LG and MG treatments were lower ( P < 0.05) than in the control and HG treatments. Peak standing crop variability of the control and HG community were greatest, which suggested that LG and MG have greater ecosystem stability.

Venous Hemodynamics After Total Hip Arthroplasty: A Comparison Between Portable vs Stationary Pneumatic Compression Devices and the Effect of Body Position.

PubMed

Berliner, Jonathan L; Ortiz, Philippe A; Lee, Yuo-Yu; Miller, Theodore T; Westrich, Geoffrey H

2018-01-01

Improvements in device design have allowed for portable pneumatic compression devices (PPCDs). However, portability results in smaller pumps that move less blood. Additionally, although patients often stand when wearing PPCDs, few studies have evaluated the hemodynamic effects of PCDs while standing. A crossover study was performed to compare a PPCD (ActiveCare+S.F.T.; Medical Compression Systems, Or Akiva, Israel) to a stationary pneumatic compression device (SPCD) (VenaFlow; DJO Global, Carlsbad, CA) on hemodynamics in supine and standing positions among 2 cohorts composed of 10 controls and 10 total hip arthroplasty patients. Differences in baseline peak venous velocity (PVV), PVV with each PCD, and delta PVV with each PCD were assessed. A multivariate analysis was performed to examine differences between cohorts, devices, and position. In both positions, the SPCD demonstrated a larger change in PVV when compared to the PPCD (P < .001). The total hip arthroplasty group had a greater delta PVV while standing when considering both PCDs together (P < .001). When considering both cohorts, delta PVV was greater while standing, only when the SPCD was used (P < .001). There was no difference between standing and supine positions when the PPCD was used. The SPCD demonstrated a greater capacity to increase PPV in the supine and standing positions. The SPCD generated greater values of PVV and delta PVV in the standing position. Although these results demonstrate a difference between devices, it is important to establish the PVV necessary to prevent VTE before one is considered more effective. Copyright © 2017 Elsevier Inc. All rights reserved.

Real-time positioning in logging: Effects of forest stand characteristics, topography, and line-of-sight obstructions on GNSS-RF transponder accuracy and radio signal propagation.

PubMed

Zimbelman, Eloise G; Keefe, Robert F

2018-01-01

Real-time positioning on mobile devices using global navigation satellite system (GNSS) technology paired with radio frequency (RF) transmission (GNSS-RF) may help to improve safety on logging operations by increasing situational awareness. However, GNSS positional accuracy for ground workers in motion may be reduced by multipath error, satellite signal obstruction, or other factors. Radio propagation of GNSS locations may also be impacted due to line-of-sight (LOS) obstruction in remote, forested areas. The objective of this study was to characterize the effects of forest stand characteristics, topography, and other LOS obstructions on the GNSS accuracy and radio signal propagation quality of multiple Raveon Atlas PT GNSS-RF transponders functioning as a network in a range of forest conditions. Because most previous research with GNSS in forestry has focused on stationary units, we chose to analyze units in motion by evaluating the time-to-signal accuracy of geofence crossings in 21 randomly-selected stands on the University of Idaho Experimental Forest. Specifically, we studied the effects of forest stand characteristics, topography, and LOS obstructions on (1) the odds of missed GNSS-RF signals, (2) the root mean squared error (RMSE) of Atlas PTs, and (3) the time-to-signal accuracy of safety geofence crossings in forested environments. Mixed-effects models used to analyze the data showed that stand characteristics, topography, and obstructions in the LOS affected the odds of missed radio signals while stand variables alone affected RMSE. Both stand characteristics and topography affected the accuracy of geofence alerts.

Real-time positioning in logging: Effects of forest stand characteristics, topography, and line-of-sight obstructions on GNSS-RF transponder accuracy and radio signal propagation

PubMed Central

2018-01-01

Real-time positioning on mobile devices using global navigation satellite system (GNSS) technology paired with radio frequency (RF) transmission (GNSS-RF) may help to improve safety on logging operations by increasing situational awareness. However, GNSS positional accuracy for ground workers in motion may be reduced by multipath error, satellite signal obstruction, or other factors. Radio propagation of GNSS locations may also be impacted due to line-of-sight (LOS) obstruction in remote, forested areas. The objective of this study was to characterize the effects of forest stand characteristics, topography, and other LOS obstructions on the GNSS accuracy and radio signal propagation quality of multiple Raveon Atlas PT GNSS-RF transponders functioning as a network in a range of forest conditions. Because most previous research with GNSS in forestry has focused on stationary units, we chose to analyze units in motion by evaluating the time-to-signal accuracy of geofence crossings in 21 randomly-selected stands on the University of Idaho Experimental Forest. Specifically, we studied the effects of forest stand characteristics, topography, and LOS obstructions on (1) the odds of missed GNSS-RF signals, (2) the root mean squared error (RMSE) of Atlas PTs, and (3) the time-to-signal accuracy of safety geofence crossings in forested environments. Mixed-effects models used to analyze the data showed that stand characteristics, topography, and obstructions in the LOS affected the odds of missed radio signals while stand variables alone affected RMSE. Both stand characteristics and topography affected the accuracy of geofence alerts. PMID:29324794

Annual climate variation modifies nitrogen induced carbon accumulation of Pinus sylvestris forests.

PubMed

Lim, Hyungwoo; Oren, Ram; Linder, Sune; From, Fredrik; Nordin, Annika; Fahlvik, Nils; Lundmark, Tomas; Näsholm, Torgny

2017-09-01

We report results from long-term simulated external nitrogen (N) input experiments in three northern Pinus sylvestris forests, two of moderately high and one of moderately low productivity, assessing effects on annual net primary production (NPP) of woody mass and its interannual variation in response to variability in weather conditions. A sigmoidal response of wood NPP to external N inputs was observed in the both higher and lower productivity stands, reaching a maximum of ~65% enhancement regardless of the native site productivity, saturating at an external N input of 4-5 g N·m -2 ·yr -1 . The rate of increase in wood NPP and the N response efficiency (RE N , increase in wood NPP per external N input) were maximized at an external N input of ~3 g N·m -2 ·yr -1 , regardless of site productivity. The maximum RE N was greater in the higher productivity than the lower productivity stand (~20 vs. ~14 g C/g N). The N-induced enhancement of wood NPP and its RE N were, however, markedly contingent on climatic variables. In both of the higher and lower productivity stands, wood NPP increased with growing season precipitation (P), but only up to ~400 mm. The sensitivity of the response to P increased with increasing external N inputs. Increasing growing season temperature (T) somewhat increased the N-induced drought effect, whereas decreasing T reduced the drought effect. These responses of wood NPP infused a large temporal variation to RE N , making the use of a fixed value unadvisable. Based on these results, we suggest that regional climate conditions and future climate scenarios should be considered when modeling carbon sequestration in response to N deposition in boreal P. sylvestris, and possibly other forests. © 2017 by the Ecological Society of America.

Free-standing few-layered graphene oxide films: selective, steady and lasting permeation of organic molecules with adjustable speeds

NASA Astrophysics Data System (ADS)

Huang, Tao; An, Qi; Luan, Xinglong; Zhang, Qian; Zhang, Yihe

2016-01-01

A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with adjustable and controllable speeds. The steady delivery of the small molecule lasted up to 9 days. Other functionalities, such as graphene-enhanced Raman spectra and electrochemical properties that could also be integrated or employed in delivery systems, were also studied for our films. We expect the special molecular delivery properties of our films to lead to new possibilities in drug/fertilizer delivery and environmental microbiological control applications.A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with adjustable and controllable speeds. The steady delivery of the small molecule lasted up to 9 days. Other functionalities, such as graphene-enhanced Raman spectra and electrochemical properties that could also be integrated or employed in delivery systems, were also studied for our films. We expect the special molecular delivery properties of our films to lead to new possibilities in drug/fertilizer delivery and environmental microbiological control applications. Electronic supplementary information (ESI) available: AFM images of GO and GO films, UV-vis spectra of delayed release, and permeation fidelities. See DOI: 10.1039/c5nr08129g

Free-standing oxide superconducting articles

DOEpatents

Wu, Xin D.; Muenchausen, Ross E.

1993-01-01

A substrate-free, free-standing epitaxially oriented superconductive film including a layer of a template material and a layer of a ceramic superconducting material is provided together with a method of making such a substrate-free ceramic superconductive film by coating an etchable material with a template layer, coating the template layer with a layer of a ceramic superconductive material, coating the layer of ceramic superconductive material with a protective material, removing the etchable material by an appropriate means so that the etchable material is separated from a composite structure including the template lay This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

Fabrication of free-standing, electrochemically active, and biocompatible graphene oxide-polyaniline and graphene-polyaniline hybrid papers.

PubMed

Yan, Xingbin; Chen, Jiangtao; Yang, Jie; Xue, Qunji; Miele, Philippe

2010-09-01

In this work, we report a low-cost technique via simple rapid-mixture polymerization of aniline using graphene oxide (GO) and graphene papers as substrates, respectively, to fabricate free-standing, flexible GO-polyaniline (PANI) and graphene-PANI hybrid papers. The morphology and microstructure of the obtained papers were characterized by FESEM, FTIR, Raman, and XRD. As results, nanostructural PANI can be deposited on the surfaces of GO and graphene papers, forming thin, lightweight, and flexible paperlike hybrid papers. The hybrid papers display a remarkable combination of excellent electrochemical performances and biocompatibility, making the paperlike materials attractive for new kinds of applications in biosciences.

Global Lunar Topography from the Deep Space Gateway for Science and Exploration

NASA Astrophysics Data System (ADS)

Archinal, B.; Gaddis, L.; Kirk, R.; Edmundson, K.; Stone, T.; Portree, D.; Keszthelyi, L.

2018-02-01

The Deep Space Gateway, in low lunar orbit, could be used to achieve a long standing goal of lunar science, collecting stereo images in two months to make a complete, uniform, high resolution, known accuracy, global topographic model of the Moon.

A Quantitative Transmission Line Experiment

ERIC Educational Resources Information Center

Johnston, D. C.; Silbernagel, B. G.

1969-01-01

Describes modifications of a commercially available strip-type transmission line, which makes possible reproducible measurements of standing waves on the line. Experimental data yield values for the characteristic impedance, phase velocity and line wavelength of radiation in the transmission line, and the dielectric constant of material in the…

Gauging Possibilities for Action Based on Friction Underfoot

ERIC Educational Resources Information Center

Joh, Amy S.; Adolph, Karen E.; Narayanan, Priya J.; Dietz, Victoria A.

2007-01-01

Standing and walking generate information about friction underfoot. Five experiments examined whether walkers use such perceptual information for prospective control of locomotion. In particular, do walkers integrate information about friction underfoot with visual cues for sloping ground ahead to make adaptive locomotor decisions? Participants…

Kirwan's Way.

ERIC Educational Resources Information Center

Fisher, Mark

1998-01-01

Ohio State University's new president, William E. Kirwan, has taken a strong stand on diversity, hiring consultants to analyze weaknesses in minority-student recruiting and personnel practices, and holding quarterly town meetings on race. Some say this exemplifies the type of commitment white male senior executives need to make if higher…

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.

The PM-200 lubrication system

NASA Technical Reports Server (NTRS)

Sliney, Harold E.

1991-01-01

Plasma sprayed composite coating of metal-bonded chromium carbide with additions of silver and thermochemically stable fluorides were previously reported to be lubricative in pin on desk bench tests from room temperature to 900 C. An early coating formulation of this type, designated as PS-200, was successfully tested as a cylinder coating in a Stirling engine at a TRRT of 760 C in a hydrogen atmosphere, and as a backup lubricant for gas bearings to 650 C. A subsequent optimization program has shown that tribological properties are further improved by increasing the solid lubricant content. The improved coating is designated as PS-212. The same powder formulation was used to make free-standing powder metallurgy (PM-212) parts by sintering or hot isostatic pressing. The process is very attractive for making parts that cannot be readily plasma sprayed such as bushings and cylinders that have small bore diameters and/or high length to diameter ratios. The properties of coatings and free-standing parts fabricated from these powders are reviewed.

Geometry of a naked singularity created by standing waves near a Schwarzschild horizon, and its application to the binary black hole problem

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

Mandel, Ilya

The most promising way to compute the gravitational waves emitted by binary black holes (BBHs) in their last dozen orbits, where post-Newtonian techniques fail, is a quasistationary approximation introduced by Detweiler and being pursued by Price and others. In this approximation the outgoing gravitational waves at infinity and downgoing gravitational waves at the holes' horizons are replaced by standing waves so as to guarantee that the spacetime has a helical Killing vector field. Because the horizon generators will not, in general, be tidally locked to the holes' orbital motion, the standing waves will destroy the horizons, converting the black holesmore » into naked singularities that resemble black holes down to near the horizon radius. This paper uses a spherically symmetric, scalar-field model problem to explore in detail the following BBH issues: (i) The destruction of a horizon by the standing waves. (ii) The accuracy with which the resulting naked singularity resembles a black hole. (iii) The conversion of the standing-wave spacetime (with a destroyed horizon) into a spacetime with downgoing waves by the addition of a 'radiation-reaction field'. (iv) The accuracy with which the resulting downgoing waves agree with the downgoing waves of a true black-hole spacetime (with horizon). The model problem used to study these issues consists of a Schwarzschild black hole endowed with spherical standing waves of a scalar field, whose wave frequency and near-horizon energy density are chosen to match those of the standing gravitational waves of the BBH quasistationary approximation. It is found that the spacetime metric of the singular, standing-wave spacetime, and its radiation-reaction-field-constructed downgoing waves are quite close to those for a Schwarzschild black hole with downgoing waves--sufficiently close to make the BBH quasistationary approximation look promising for non-tidally-locked black holes.« less

BioEarth: Envisioning and developing a new regional earth system model to inform natural and agricultural resource management

DOE PAGES

Adam, Jennifer C.; Stephens, Jennie C.; Chung, Serena H.; ...

2014-04-24

Uncertainties in global change impacts, the complexities associated with the interconnected cycling of nitrogen, carbon, and water present daunting management challenges. Existing models provide detailed information on specific sub-systems (e.g., land, air, water, and economics). An increasing awareness of the unintended consequences of management decisions resulting from interconnectedness of these sub-systems, however, necessitates coupled regional earth system models (EaSMs). Decision makers’ needs and priorities can be integrated into the model design and development processes to enhance decision-making relevance and “usability” of EaSMs. BioEarth is a research initiative currently under development with a focus on the U.S. Pacific Northwest region thatmore » explores the coupling of multiple stand-alone EaSMs to generate usable information for resource decision-making. Direct engagement between model developers and non-academic stakeholders involved in resource and environmental management decisions throughout the model development process is a critical component of this effort. BioEarth utilizes a bottom-up approach for its land surface model that preserves fine spatial-scale sensitivities and lateral hydrologic connectivity, which makes it unique among many regional EaSMs. Here, we describe the BioEarth initiative and highlights opportunities and challenges associated with coupling multiple stand-alone models to generate usable information for agricultural and natural resource decision-making.« less

Estimating Value Contribution of Tree and Stand Condition

Treesearch

R. Joss Hanna; Richard P. Thompson; Douglas D. Piirto; Jay E. Noel

1997-01-01

Key issues in encouraging forest management at the interface level in the oak woodlands are fire abatement, stand improvement, infection reduction, and hazard tree removal. The development of effective management prescriptions for stand improvement and economic returns provide guidance for homeowners, appraisers, and realtors. The purpose of this research project was...

Ice damage effects on thinned loblolly pine (Pinus taeda) stands in southeastern Oklahoma

Treesearch

Thomas Hennessey; Robert Heinemann; Randal Holeman; Rodney Will; Thomas Lynch; Douglas Stevenson; Edward Lorenzi; Giulia Caterina

2012-01-01

Loblolly pine plantations in southeastern Oklahoma and Arkansas are periodically subjected to damaging ice storms. Following one such event, damage to a 25-year-old, previously thinned stand was assessed and quantitative relationships were developed to guide stand management in ice storm-prone areas.

Are prescribed fire and thinning dominant processes affecting snag occurrence at a landscape scale?

DOE PAGES

Zarnoch, Stanley J.; Blake, John I.; Parresol, Bernard R.

2014-11-01

Snags are standing dead trees that are an important component in the nesting habitat of birds and other species. Although snag availability is believed to limit populations in managed and non-managed forests, little data are available to evaluate the relative effect of stand conditions and management on snag occurrence. We analyzed point sample data from an intensive forest inventory within an 80,000 ha landscape for four major forest types to support the hypotheses that routine low-intensity prescribed fire would increase, and thinning would decrease, snag occurrence. We employed path analysis to define a priori causal relationships to determine the directmore » and indirect effects of site quality, age, relative stand density index and fire for all forest types and thinning effects for loblolly pine and longleaf pine. Stand age was an important direct effect for loblolly pine, mixed pine-hardwoods and hardwoods, but not for longleaf pine. Snag occurrence in loblolly pine was increased by prescribed fire and decreased by thinning which confirmed our initial hypotheses. Although fire was not important in mixed pine-hardwoods, it was for hardwoods but the relationship depended on site quality. For longleaf pine the relative stand density index was the dominant variable affecting snag occurrence, which increased as the density index decreased. Site quality, age and thinning had significant indirect effects on snag occurrence in longleaf pine through their effects on the density index. Although age is an important condition affecting snag occurrence for most forest types, path analysis revealed that fire and density management practices within certain forest types can also have major beneficial effects, particularly in stands less than 60 years old.« less

Critical thinking: concept analysis from the perspective of Rodger's evolutionary method of concept analysis

PubMed Central

Carbogim, Fábio da Costa; de Oliveira, Larissa Bertacchini; Püschel, Vilanice Alves de Araújo

2016-01-01

ABSTRACT Objective: to analyze the concept of critical thinking (CT) in Rodger's evolutionary perspective. Method: documentary research undertaken in the Cinahl, Lilacs, Bdenf and Dedalus databases, using the keywords of 'critical thinking' and 'Nursing', without limitation based on year of publication. The data were analyzed in accordance with the stages of Rodger's conceptual model. The following were included: books and articles in full, published in Portuguese, English or Spanish, which addressed CT in the teaching and practice of Nursing; articles which did not address aspects related to the concept of CT were excluded. Results: the sample was made up of 42 works. As a substitute term, emphasis is placed on 'analytical thinking', and, as a related factor, decision-making. In order, the most frequent preceding and consequent attributes were: ability to analyze, training of the student nurse, and clinical decision-making. As the implications of CT, emphasis is placed on achieving effective results in care for the patient, family and community. Conclusion: CT is a cognitive skill which involves analysis, logical reasoning and clinical judgment, geared towards the resolution of problems, and standing out in the training and practice of the nurse with a view to accurate clinical decision-making and the achieving of effective results. PMID:27598376

Occupational Physical Activity Habits of UK Office Workers: Cross-Sectional Data from the Active Buildings Study.

PubMed

Smith, Lee; Sawyer, Alexia; Gardner, Benjamin; Seppala, Katri; Ucci, Marcella; Marmot, Alexi; Lally, Pippa; Fisher, Abi

2018-06-09

Habitual behaviours are learned responses that are triggered automatically by associated environmental cues. The unvarying nature of most workplace settings makes workplace physical activity a prime candidate for a habitual behaviour, yet the role of habit strength in occupational physical activity has not been investigated. Aims of the present study were to: (i) document occupational physical activity habit strength; and (ii) investigate associations between occupational activity habit strength and occupational physical activity levels. A sample of UK office-based workers ( n = 116; 53% female, median age 40 years, SD 10.52) was fitted with activPAL accelerometers worn for 24 h on five consecutive days, providing an objective measure of occupational step counts, stepping time, sitting time, standing time and sit-to-stand transitions. A self-report index measured the automaticity of two occupational physical activities (“being active” (e.g., walking to printers and coffee machines) and “stair climbing”). Adjusted linear regression models investigated the association between occupational activity habit strength and objectively-measured occupational step counts, stepping time, sitting time, standing time and sit-to-stand transitions. Eighty-one per cent of the sample reported habits for “being active”, and 62% reported habits for “stair climbing”. In adjusted models, reported habit strength for “being active” were positively associated with average occupational sit-to-stand transitions per hour (B = 0.340, 95% CI: 0.053 to 0.627, p = 0.021). “Stair climbing” habit strength was unexpectedly negatively associated with average hourly stepping time (B = −0.01, 95% CI: −0.01 to −0.00, p = 0.006) and average hourly occupational step count (B = −38.34, 95% CI: −72.81 to −3.88, p = 0.030), which may reflect that people with stronger stair-climbing habits compensate by walking fewer steps overall. Results suggest that stair-climbing and office-based occupational activity can be habitual. Interventions might fruitfully promote habitual workplace activity, although, in light of potential compensation effects, such interventions should perhaps focus on promoting moderate-intensity activity.

Effects of disease severity and medication state on postural control asymmetry during challenging postural tasks in individuals with Parkinson's disease.

PubMed

Barbieri, Fabio A; Polastri, Paula F; Baptista, André M; Lirani-Silva, Ellen; Simieli, Lucas; Orcioli-Silva, Diego; Beretta, Victor S; Gobbi, Lilian T B

2016-04-01

The aim of this study was to investigate the effects of disease severity and medication state on postural control asymmetry during challenging tasks in individuals with Parkinson's disease (PD). Nineteen people with PD and 11 neurologically healthy individuals performed three standing task conditions: bipedal standing, tandem and unipedal adapted standing; the individuals with PD performed the tasks in ON and OFF medication state. The participants with PD were distributed into 2 groups according to disease severity: unilateral group (n=8) and bilateral group (n=11). The two PD groups performed the evaluations both under and without the medication. Two force plates were used to analyze the posture. The symmetric index was calculated for various of center of pressure. ANOVA one-way (groups) and two-way (PD groups×medication), with repeated measures for medication, were calculated. For main effects of group, the bilateral group was more asymmetric than CG. For main effects of medication, only unipedal adapted standing presented effects of PD medication. There was PD groups×medication interaction. Under the effects of medication, the unilateral group presented lower asymmetry of RMS in anterior-posterior direction and area than the bilateral group in unipedal adapted standing. In addition, the unilateral group presented lower asymmetry of mean velocity, RMS in anterior-posterior direction and area in unipedal standing and area in tandem adapted standing after a medication dose. Postural control asymmetry during challenging postural tasks was dependent on disease severity and medication state in people with PD. The bilateral group presented higher postural control asymmetry than the control and unilateral groups in challenging postural tasks. Finally, the medication dose was able to reduce postural control asymmetry in the unilateral group during challenging postural tasks. Copyright © 2015 Elsevier B.V. All rights reserved.

A Pine Is a Pine and a Spruce Is a Spruce--The Effect of Tree Species and Stand Age on Epiphytic Lichen Communities.

PubMed

Bäcklund, Sofia; Jönsson, Mari; Strengbom, Joachim; Frisch, Andreas; Thor, Göran

2016-01-01

With an increasing demand for forest-based products, there is a growing interest in introducing fast-growing non-native tree species in forest management. Such introductions often have unknown consequences for native forest biodiversity. In this study, we examine epiphytic lichen species richness and species composition on the trunks of non-native Pinus contorta and compare these to the native Pinus sylvestris and Picea abies in managed boreal forests in northern Sweden across a chronosequence of age classes. Overall, we recorded a total of 66,209 lichen occurrences belonging to 57 species in the 96 studied forest stands. We found no difference in species richness of lichens between stands of P. contorta and P. sylvestris, but stands of P. abies had higher total species richness. However, species richness of lichens in stands of P. abies decreased with increasing stand age, while no such age effect was detected for P. contorta and P. sylvestris. Lichen species composition progressively diverged with increasing stand age, and in 30-year-old stands all three tree species showed species-specific assemblages. Epiphytic lichen assemblages in stands of 30-year-old P. contorta were influenced by greater basal area, canopy closure, and average diameter at breast height, P. abies stands by higher branch density and canopy closure, and stands of P. sylvestris by greater bark crevice depth. Differences in lichen species richness and composition were mainly explained by canopy closure and habitat availability, and the greater canopy closure in mature P. abies stands promoted the colonization and growth of calicioid lichen species. Our results indicate that the non-native P. contorta have similar species richness as the native P. sylvestris. The main difference in lichen species richness and composition is between P. abies and Pinus spp. in managed forests of boreal Sweden.

A Pine Is a Pine and a Spruce Is a Spruce – The Effect of Tree Species and Stand Age on Epiphytic Lichen Communities

PubMed Central

Bäcklund, Sofia; Jönsson, Mari; Strengbom, Joachim; Frisch, Andreas; Thor, Göran

2016-01-01

With an increasing demand for forest-based products, there is a growing interest in introducing fast-growing non-native tree species in forest management. Such introductions often have unknown consequences for native forest biodiversity. In this study, we examine epiphytic lichen species richness and species composition on the trunks of non-native Pinus contorta and compare these to the native Pinus sylvestris and Picea abies in managed boreal forests in northern Sweden across a chronosequence of age classes. Overall, we recorded a total of 66,209 lichen occurrences belonging to 57 species in the 96 studied forest stands. We found no difference in species richness of lichens between stands of P. contorta and P. sylvestris, but stands of P. abies had higher total species richness. However, species richness of lichens in stands of P. abies decreased with increasing stand age, while no such age effect was detected for P. contorta and P. sylvestris. Lichen species composition progressively diverged with increasing stand age, and in 30-year-old stands all three tree species showed species-specific assemblages. Epiphytic lichen assemblages in stands of 30-year-old P. contorta were influenced by greater basal area, canopy closure, and average diameter at breast height, P. abies stands by higher branch density and canopy closure, and stands of P. sylvestris by greater bark crevice depth. Differences in lichen species richness and composition were mainly explained by canopy closure and habitat availability, and the greater canopy closure in mature P. abies stands promoted the colonization and growth of calicioid lichen species. Our results indicate that the non-native P. contorta have similar species richness as the native P. sylvestris. The main difference in lichen species richness and composition is between P. abies and Pinus spp. in managed forests of boreal Sweden. PMID:26799558

Depth-Based Detection of Standing-Pigs in Moving Noise Environments.

PubMed

Kim, Jinseong; Chung, Yeonwoo; Choi, Younchang; Sa, Jaewon; Kim, Heegon; Chung, Yongwha; Park, Daihee; Kim, Hakjae

2017-11-29

In a surveillance camera environment, the detection of standing-pigs in real-time is an important issue towards the final goal of 24-h tracking of individual pigs. In this study, we focus on depth-based detection of standing-pigs with "moving noises", which appear every night in a commercial pig farm, but have not been reported yet. We first apply a spatiotemporal interpolation technique to remove the moving noises occurring in the depth images. Then, we detect the standing-pigs by utilizing the undefined depth values around them. Our experimental results show that this method is effective for detecting standing-pigs at night, in terms of both cost-effectiveness (using a low-cost Kinect depth sensor) and accuracy (i.e., 94.47%), even with severe moving noises occluding up to half of an input depth image. Furthermore, without any time-consuming technique, the proposed method can be executed in real-time.

Bubble-based acoustic radiation force using chirp insonation to reduce standing wave effects.

PubMed

Erpelding, Todd N; Hollman, Kyle W; O'Donnell, Matthew

2007-02-01

Bubble-based acoustic radiation force can measure local viscoelastic properties of tissue. High intensity acoustic waves applied to laser-generated bubbles induce displacements inversely proportional to local Young's modulus. In certain instances, long pulse durations are desirable but are susceptible to standing wave artifacts, which corrupt displacement measurements. Chirp pulse acoustic radiation force was investigated as a method to reduce standing wave artifacts. Chirp pulses with linear frequency sweep magnitudes of 100, 200 and 300 kHz centered around 1.5 MHz were applied to glass beads within gelatin phantoms and laser-generated bubbles within porcine lenses. The ultrasound transducer was translated axially to vary standing wave conditions, while comparing displacements using chirp pulses and 1.5 MHz tone burst pulses of the same duration and peak rarefactional pressure. Results demonstrated significant reduction in standing wave effects using chirp pulses, with displacement proportional to acoustic intensity and bubble size.

Bubble-Based Acoustic Radiation Force Using Chirp Insonation to Reduce Standing Wave Effects

PubMed Central

Erpelding, Todd N.; Hollman, Kyle W.; O’Donnell, Matthew

2007-01-01

Bubble-based acoustic radiation force can measure local viscoelastic properties of tissue. High intensity acoustic waves applied to laser-generated bubbles induce displacements inversely proportional to local Young’s modulus. In certain instances, long pulse durations are desirable but are susceptible to standing wave artifacts, which corrupt displacement measurements. Chirp pulse acoustic radiation force was investigated as a method to reduce standing wave artifacts. Chirp pulses with linear frequency sweep magnitudes of 100, 200, and 300 kHz centered around 1.5 MHz were applied to glass beads within gelatin phantoms and laser-generated bubbles within porcine lenses. The ultrasound transducer was translated axially to vary standing wave conditions, while comparing displacements using chirp pulses and 1.5 MHz tone burst pulses of the same duration and peak rarefactional pressure. Results demonstrated significant reduction in standing wave effects using chirp pulses, with displacement proportional to acoustic intensity and bubble size. PMID:17306697

Decomposition of standing litter in arid grasslands: Interactions between sunlight, non-rainfall moisture, microbes, and plant traits

NASA Astrophysics Data System (ADS)

Logan, J. R. V.; Jacobson, P. J.; Jacobson, K. M.; Evans, S.

2017-12-01

Although arid lands make up 40% of the Earth's land surface, we still lack a strong understanding of carbon cycling and plant decomposition in these systems. One reason for this is that field studies typically only focus on decomposition at or below the ground surface even though standing dead litter (material that has not yet fallen to the ground) accounts for more than 50% of total necromass in many of these systems. While recent work has begun to recognize the important and unique aspects of standing litter decomposition, few studies have investigated specific mechanisms controlling rates of mass loss. We hypothesized that initial photodegradation of the outer plant cuticle of standing litter is an important determinant of litter decomposition because this process increases moisture absorption and subsequent opportunities for biological decomposition. Our preliminary results offer support for this hypothesis. We found that standing grass stems with their cuticles artificially removed had greater water absorbance and more than 400% greater mass loss over a 6-month period relative to controls with intact cuticles. Additionally, spectroscopic measurements of cuticle integrity showed damage to the litter surface after a period of extended photodegradation, allowing increased moisture uptake during simulated fog/dew events. These findings are especially important in the context of recent work by us and others showing that non-rainfall moisture (fog, dew, and water vapor) plays a much larger role in arid land decomposition than previously thought. Improving our understanding of the mechanisms driving decomposition of standing litter will enable us to develop a more predictive understanding of carbon storage in arid lands.

The evaluation of different forest structural indices to predict the stand aboveground biomass of even-aged Scotch pine (Pinus sylvestris L.) forests in Kunduz, Northern Turkey.

PubMed

Ercanli, İlker; Kahriman, Aydın

2015-03-01

We assessed the effect of stand structural diversity, including the Shannon, improved Shannon, Simpson, McIntosh, Margelef, and Berger-Parker indices, on stand aboveground biomass (AGB) and developed statistical prediction models for the stand AGB values, including stand structural diversity indices and some stand attributes. The AGB prediction model, including only stand attributes, accounted for 85 % of the total variance in AGB (R (2)) with an Akaike's information criterion (AIC) of 807.2407, Bayesian information criterion (BIC) of 809.5397, Schwarz Bayesian criterion (SBC) of 818.0426, and root mean square error (RMSE) of 38.529 Mg. After inclusion of the stand structural diversity into the model structure, considerable improvement was observed in statistical accuracy, including 97.5 % of the total variance in AGB, with an AIC of 614.1819, BIC of 617.1242, SBC of 633.0853, and RMSE of 15.8153 Mg. The predictive fitting results indicate that some indices describing the stand structural diversity can be employed as significant independent variables to predict the AGB production of the Scotch pine stand. Further, including the stand diversity indices in the AGB prediction model with the stand attributes provided important predictive contributions in estimating the total variance in AGB.

Situating the Embodied Mind in a Landscape of Standing Affordances for Living Without Chairs: Materializing a Philosophical Worldview.

PubMed

Rietveld, Erik

2016-07-01

Sitting too much is unhealthy, but a widespread habit in many societies. Realizing behavioral change in this area is hard. Our societies promote being seated via the way its places are structured: they are filled with chairs for example. How can we make healthier environments that invite people to move around more? This article shows how philosophical research in the area of embodied/enactive cognitive science let to a built vision for the office of the future, of 2025. Multidisciplinary studio RAAAF [Rietveld Architecture-Art-Affordances] and visual artist Barbara Visser built this world without chairs, titled The End of Sitting. This large rock-like landscape integrates many affordances for standing. Affordances are the possibilities for action provided by the environment. This landscape of standing affordances allows people to work standing while being supported by the material structure of the environment. This unorthodox working landscape is both an enactive art installation and the materialization of a philosophical worldview that understands people as embodied minds situated in a landscape of affordances. It stimulates reflection on the way built environments can naturally invite more active and healthy behavior.

Effects of planting density and genotype on canopy size, canopy structure, and growth of 25-year-old loblolly pine stands in southeastern Oklahoma

Treesearch

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

2013-01-01

Leaf biomass and its display within the canopy are important driving variables of stand growth because they reflect a tree or stand’s capacity to intercept radiation, reduce carbon dioxide, and transpire water. We determined the effects of planting density (4- by 4-, 6- by 6-, 8- by 8-, and 10- by 10-foot spacing) on annual needle fall biomass, intercepted radiation,...

Comparison of tree size structure and growth for partially harvested and even-aged hemlock-spruce stands in southeast Alaska

Treesearch

Robert L. Deal; Troy Heithecker; Eric K. Zenner

2010-01-01

The effects of partial cutting on tree size structure and stand growth were evaluated in 52 plots in 13 stands in southeast Alaska that were partially harvested 53 to 96 years ago and compared with 50-year-old even-aged stands that developed after clearcutting. The net basal-area growth was greater in the partially cut plots than in the uncut plots, and basal-area...

The influece of forest gaps on some properties of humus in a managed beech forest, northern Iran

NASA Astrophysics Data System (ADS)

Vajari, K. A.

2015-10-01

The present research focuses on the effect of eight-year-old artificially created gaps on some properties of humus in managed beech-dominated stand in Hyrcanian forest of northern Iran. In this study, six-teen gaps were sampled in site and were classified into four classes (small, medium, large, and very large) with four replications for each. Humus sampling was carried out at the centre and at the cardinal points within each gap as well as in the adjacent closed stand, separately, as composite samples. The variables of organic carbon, P, K, pH, and total N were measured for each sample. It was found that the gap size had significant effect only on total N (%) and organic carbon (%) in beech stand. The amount of potassium clearly differed among three positions in beech forest. The adjacent stand had higher significantly potassium than center and edge of gaps. Different amount of potassium was detected in gap center and gap edge. Comparison of humus properties between gaps and its adjacent stand pointed to the higher amount of potassium in adjacent stand than that in gaps but there was no difference between them regarding other humus properties. According to the results, it can be concluded that there is relatively similar condition among gaps and closed adjacent stands in terms of humus properties eight years after logging in the beech stand.

Habitat fragmentation leads to reduced pollinator visitation, fruit production and recruitment in urban mangrove forests.

PubMed

Hermansen, Tyge D; Minchinton, Todd E; Ayre, David J

2017-10-01

Mangrove forests worldwide undergo anthropogenic fragmentation that may threaten their existence, and yet there have been few tests of the effects of fragmentation on demographic processes critical for mangrove regeneration. Predicting the effects of habitat fragmentation on mangroves is problematic as pollinators may move more freely across water than terrestrial habitat, and propagules can be widely dispersed by water. Here, within each of two estuaries, we compared pollinator diversity and activity, reproductive effort and output, and rates of recruitment for sets of three large (>1500 trees), medium (300-500) and small (<50) stands. As predicted, most measures of reproductive activity and success were inversely related to stand size with large stands typically producing significantly more and larger fruit, and significantly more seedlings. Most strikingly, we found the effect of fragmentation on the abundance of pollinators (honeybees), the production and quality of fruit and the survival rate of seedlings to be similar, showing significant reduction of recruitment in small stands. This study provides the first rigorous evidence that recruitment of mangroves, like for many terrestrial plants, is negatively impacted by habitat fragmentation. From a management perspective, we argue that in the short term our data imply the importance of conserving the largest possible stands. However, additional work is needed to determine (1) the proportion of recruits within small stands that originate within large stands, (2) how seedling performance varies with fruit size and genotype, and (3) how seedling size and performance vary with the abundance and diversity of pollen.

77 FR 59029 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-25

... information to the Office of Management and Budget (``OMB'') for extension and approval. Regulation R, Rule... dealer) to notify the bank if the broker or dealer makes certain determinations regarding the financial... worth or institutional status or suitability or sophistication standing as well as a bank employee's...

Improved acoustic levitation apparatus

NASA Technical Reports Server (NTRS)

Berge, L. H.; Johnson, J. L.; Oran, W. A.; Reiss, D. A.

1980-01-01

Concave driver and reflector enhance and shape levitation forces in acoustic resonance system. Single-mode standing-wave pattern is focused by ring element situated between driver and reflector. Concave surfaces increase levitating forces up to factor of 6 as opposed to conventional flat surfaces, making it possible to suspend heavier objects.

BCI`s RBSM test methods: Eight years in the making

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

NONE

1993-03-01

RBSM stands for recombinant battery separator mat. This is the acronym chosen after a lot of debate during eight years of committee work to develop test methods to characterize separators which are used in valve regulated lead acid batteries. This paper discusses the test methods.

Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure

PubMed Central

Miquelajauregui, Yosune; Cumming, Steven G.; Gauthier, Sylvie

2016-01-01

It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity. PMID:26919456

Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure.

PubMed

Miquelajauregui, Yosune; Cumming, Steven G; Gauthier, Sylvie

2016-01-01

It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity.

Standing Height as a Prevention Measure for Overuse Injuries of the Back in Alpine Ski Racing: A Kinematic and Kinetic Study of Giant Slalom

PubMed Central

Spörri, Jörg; Kröll, Josef; Fasel, Benedikt; Aminian, Kamiar; Müller, Erich

2018-01-01

Background: In alpine ski racing, typical loading patterns of the back include a combined occurrence of spinal bending, torsion, and high peak loads. These factors are known to be associated with high spinal disc loading and have been suggested to be attributable to different types of spine deterioration. However, little is known about the effect of standing height (ie, the distance between the bottom of the running surface of the ski and the ski boot sole) on the aforementioned back loading patterns. Purpose: To investigate the effect of reduced standing height on the skier’s overall trunk kinematics and the acting ground-reaction forces in giant slalom (GS) from an overuse injury prevention perspective. Study Design: Controlled laboratory study. Methods: Seven European Cup–level athletes skied a total of 224 GS turns with 2 different pairs of skis varying in standing height. Their overall trunk movement (frontal bending, lateral bending, and torsion angles) was measured based on 2 inertial measurement units located at the sacrum and sternum. Pressure insoles were used to determine the total ground-reaction force. Results: During the turn phase in which the greatest spinal disc loading is expected to occur, significantly lower total ground-reaction forces were observed for skis with a decreased standing height. Simultaneously, the skier’s overall trunk movement (ie, frontal bending, lateral bending, and torsion angles) remained unwaveringly high. Conclusion: Standing height is a reasonable measure to reduce the skier’s overall back loading in GS. Yet, when compared with the effects achievable by increased gate offsets in slalom, for instance, the preventative benefits of decreased standing height seem to be rather small. Clinical Relevance: To reduce the magnitude of overall back loading in GS and to prevent overuse injuries of the back, decreasing standing height might be an efficient approach. Nevertheless, the clinical relevance of the current findings, as well as the effectiveness of the measure “reduced standing height,” must be verified by epidemiological studies before its preventative potential can be judged as conclusive. PMID:29344540

Uses and abuses of multipliers in the stand prognosis model

Treesearch

David A. Hamilton

1994-01-01

Users of the Stand Prognosis Model may have difficulties in selecting the proper set of multipliers to simulate a desired effect or in determining the appropriate value to assign to selected multipliers. A series of examples describe impact of multipliers on simulated stand development. Guidelines for the proper use of multipliers are presented....

Effects of thinning young forests on chanterelle mushroom production.

Treesearch

David Pilz; Randy Molina; Jim. Mayo

2006-01-01

Chanterelle productivity responses were investigated in a replicated, landscape-scale thinning experiment in 50-year-old Douglas-fir stands in the Cascade Range of Oregon. Chanterelle numbers and weight were significantly decreased by thinning the first year after logging more so in heavily thinned stands than lightly thinned stands for chanterelle numbers. Nearly all...

How to use the Stand-Damage Model: Version 2.0. (Computer program)

Treesearch

J.J. Colbert; George Racin

2001-01-01

The Stand-Damage Model simulates the growth of a forest stand, a spatially homogeneous collection of trees growing on a site. The model simulates growth from an initial inventory, user-prescribed management practices, and the effects of gypsy moth defoliation. Here we provide installation and operating instructions for Version 2.0.

Effect of height adjustable desks on standing time, discomfort, and productivity of office workers with sedentary occupations

USDA-ARS?s Scientific Manuscript database

Sedentary jobs promote weight gain and health risks. Interrupting sitting with standing is protective against sitting-related health risks. However, standing for portions of the workday will not be accepted if it reduces comfort or productivity. This study determined the initial changes from baselin...

Characteristics of gaps and natural regeneration in mature longleaf pine flatwoods ecosystems

Treesearch

Jennifer L. Gagnon; Eric J. Jokela; W.K. Moser; Dudley A. Huber

2004-01-01

Developing uneven-aged structure in mature stands of longleaf pine requires scientifically based silvicultural systems that are reliable, productive and sustainable. Understanding seedling responses to varying levels of site resource availability within forest gaps is essential for effectively converting even-aged stands to uneven-aged stands. A project was initiated...

Effect of ammate on unwanted growth in oak--yellow-poplar stands in New Jersey

Treesearch

S. Little; H. A. Somes

1954-01-01

Stands of mixed oaks and yellow-poplar form the most valuable forest crop on many sites in central and northern New Jersey and in the Delaware Valley of southern New Jersey. However, these stands often contain shrubs and low-value hardwood trees that prevent satisfactory restocking of cutover areas.

Muscle activity patterns and spinal shrinkage in office workers using a sit-stand workstation versus a sit workstation.

PubMed

Gao, Ying; Cronin, Neil J; Pesola, Arto J; Finni, Taija

2016-10-01

Reducing sitting time by means of sit-stand workstations is an emerging trend, but further evidence is needed regarding their health benefits. This cross-sectional study compared work time muscle activity patterns and spinal shrinkage between office workers (aged 24-62, 58.3% female) who used either a sit-stand workstation (Sit-Stand group, n = 10) or a traditional sit workstation (Sit group, n = 14) for at least the past three months. During one typical workday, muscle inactivity and activity from quadriceps and hamstrings were monitored using electromyography shorts, and spinal shrinkage was measured using stadiometry before and after the workday. Compared with the Sit group, the Sit-Stand group had less muscle inactivity time (66.2 ± 17.1% vs. 80.9 ± 6.4%, p = 0.014) and more light muscle activity time (26.1 ± 12.3% vs. 14.9 ± 6.3%, p = 0.019) with no significant difference in spinal shrinkage (5.62 ± 2.75 mm vs. 6.11 ± 2.44 mm). This study provides evidence that working with sit-stand workstations can promote more light muscle activity time and less inactivity without negative effects on spinal shrinkage. Practitioner Summary: This cross-sectional study compared the effects of using a sit-stand workstation to a sit workstation on muscle activity patterns and spinal shrinkage in office workers. It provides evidence that working with a sit-stand workstation can promote more light muscle activity time and less inactivity without negative effects on spinal shrinkage.

Influence of Human Pressure on Forest Resources and Productivity at Stand and Tree Scales: The Case Study of Yunnan Pine in SW China

PubMed Central

HINCKLEY, Thomas M.; CHI, Phillip; HAGMANN, Keala; HARRELL, Stevan; SCHMIDT, Amanda Henck; URGENSON, Lauren; ZENG, Zong-yong

2015-01-01

This paper examines human impact on stands and individual trees of Pinus yunnanensis growing near the small mountain villages of Pianshui and Yangjuan in southwestern Sichuan Province, China. In an effort to assess whether use of these forests was sustainable, we examined the effects of human use in two ways. First, we directly measured the effect of cutting branches, for fuel and fodder, on tree growth. We hypothesized that branch cutting would negatively impact tree growth. We established 12 plots on four hills and compared 14 pairs of trees, one tree in each pair with an apparently full crown and the other with a considerable portion of the crown removed. Second, we assessed stand and tree properties over a 500 m elevation gradient above the villages where we hypothesized that as elevation increases, stand and tree properties should show fewer human impacts. Although extensive branch cutting reduced the live crown, tree height and diameter, compensatory processes likely enabled trees to recover and to add basal area increments (BAIs) similar to those added by trees with full crowns. Trees and stands close to villages showed less growth and lower basal areas, respectively, than stands and trees at intermediate or distant elevations from villages. Areas relatively close to the villages showed considerable effects of human-related disturbances such as branch cutting, grazing, tree and shrub removal, losses of litter, and human and animal trails. Such areas had increased soil erosion and often loss of the ‘A’ horizon. Stands close to villages had younger trees, lower stand basal areas, smaller basal area increments, and more stumps. Our results suggest an increasingly vulnerable interface between occupants of these two villages and their surrounding forests. PMID:26478727

Comparison of the effective dose rate to aircrew members using hybrid computational phantoms in standing and sitting postures.

PubMed

Alves, M C; Galeano, D C; Santos, W S; Lee, Choonsik; Bolch, Wesley E; Hunt, John G; da Silva, A X; Carvalho, A B

2016-12-01

Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members. We found that although the better description of the posture in which the aircrews are exposed, the results of the effective dose rate calculated with the phantom in the sitting posture were very similar to the results of the phantom in the standing posture. In fact we observed only a 1% difference. These findings indicate the adequacy of the use of dose conversion coefficients for the phantom in the standing posture in aircrew dosimetry. We also validated our results comparing the effective dose rate obtained using the standing phantom with values reported in the literature. It was observed that the results presented in this study are in good agreement with other authors (the differences are below 30%) who have measured and calculated effective dose rates using different phantoms.

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.

Impacts of prescribed fire on Pinus rigida Mill. in upland forests of the Atlantic Coastal Plain.

PubMed

Carlo, Nicholas J; Renninger, Heidi J; Clark, Kenneth L; Schäfer, Karina V R

2016-08-01

A comparative analysis of the impacts of prescribed fire on three upland forest stands in the Northeastern Atlantic Plain, NJ, USA, was conducted. Effects of prescribed fire on water use and gas exchange of overstory pines were estimated via sap-flux rates and photosynthetic measurements on Pinus rigida Mill. Each study site had two sap-flux plots, one experiencing prescribed fire and one control (unburned) plot for comparison before and after the fire. We found that photosynthetic capacity in terms of Rubisco-limited carboxylation rate and intrinsic water-use efficiency was unaffected, while light compensation point and dark respiration rate were significantly lower in the burned vs control plots post-fire. Furthermore, quantum yield in pines in the pine-dominated stands was less affected than pines in the mixed oak/pine stand, as there was an increase in quantum yield in the oak/pine stand post-fire compared with the control (unburned) plot. We attribute this to an effect of forest type but not fire per se. Average daily sap-flux rates of the pine trees increased compared with control (unburned) plots in pine-dominated stands and decreased in the oak/pine stand compared with control (unburned) plots, potentially due to differences in fuel consumption and pre-fire sap-flux rates. Finally, when reference canopy stomatal conductance was analyzed, pines in the pine-dominated stands were more sensitive to changes in vapor pressure deficit (VPD), while stomatal responses of pines in the oak/pine stand were less affected by VPD. Therefore, prescribed fire affects physiological functioning and water use of pines, but the effects may be modulated by forest stand type and fuel consumption pattern, which suggests that these factors may need to be taken into account for forest management in fire-dominated systems. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of Standing and Light-Intensity Walking and Cycling on 24-h Glucose.

PubMed

Crespo, Noe C; Mullane, Sarah L; Zeigler, Zachary S; Buman, Matthew P; Gaesser, Glenn A

2016-12-01

This study aimed to compare 24-h and postprandial glucose responses to incremental intervals of standing (STAND), walking (WALK), and cycling (CYCLE) to a sit-only (SIT) condition. Nine overweight/obese (body mass index = 29 ± 3 kg·m) adults (30 ± 15 yr) participated in this randomized crossover full-factorial study, with each condition performed 1 wk apart. STAND, CYCLE, and WALK intervals increased from 10 to 30 min·h (2.5 h total) during an 8-h workday. WALK (1.0 mph) and STAND were matched for upright time, and WALK and CYCLE were matched for energy expenditure (~2 METs). Continuous interstitial glucose monitoring was performed for 24 h to include the 8-h workday (LAB), after-work evening hours (EVE), and sleep (SLEEP). Three 2-h postprandial periods were also analyzed. Linear mixed models were used to test for condition differences. Compared with SIT (5.7 ± 1.0 mmol·L), mean 24-h glucose during STAND (5.4 ± 0.9 mmol·L) and WALK (5.3 ± 0.9 mmol·L) were lower, and CYCLE (5.1 ± 1.0 mmol·L) was lower than all other conditions (all P < 0.001). During LAB and EVE, mean glucose was lower for STAND, WALK, and CYCLE compared with SIT (P < 0.001). During SLEEP, the mean glucose for CYCLE was lower than all other conditions (P < 0.001). Compared with SIT, cumulative 6-h postprandial mean glucose was 5%-12% lower (P < 0.001) during STAND, WALK, and CYCLE, and 6-h postprandial glucose integrated area under the curve was 24% lower during WALK (P < 0.05) and 44% lower during CYCLE (P < 0.001). Replacing sitting with regular intervals of standing or light-intensity activity during an 8-h workday reduces 24-h and postprandial glucose. These effects persist during evening hours, with CYCLE having the largest and most sustained effect.

Proceedings: Symposium on Piloting and VTS Systems.

DTIC Science & Technology

1980-05-01

make ships even safer . Improvements will include secondary steering, crewmen standing by with the anchor, and a general operational upgrading of ships...not be seen as an attempt to put somebody out of a job or as an attempt to make it more difficult for someone to get a license. Simulation is not, and...that I have seen in many years was the first picture of this qlobe of ours taken from outer space. It is a very fragile thing. Yet it is a vast thing

Finding Platinum-Coating Gaps On Titanium Anodes

NASA Technical Reports Server (NTRS)

Bodemeijer, Ronnald; Flowers, Cecil E.

1990-01-01

Simple procedure makes gaps visible to eye. New gap-detection method consists of plating thin layer of non-silver-colored metal like copper or gold on anode. Contrast in color between plated metal and bare anode material makes gaps stand out. If anode passes inspection, copper or gold plate removable by reversal of test-plating current. Remains to be determined whether test plating and removal damages anode. New method simpler and more economical than previous attempts to identify gaps in platinum.

Effect of Experimentally Manipulated Fire Regimes on the Response of Forests to Drought

NASA Astrophysics Data System (ADS)

Refsland, T. K.; Knapp, B.; Fraterrigo, J.

2017-12-01

Climate change is expected to increase drought stress in many forests and alter fire regimes. Fire can reduce tree density and thus competition for limited water, but the effects of changing fire regimes on forest productivity during drought remain poorly understood. We measured the annual ring-widths of adult oak (Quercus spp.) trees in Mark Twain National Forest, Missouri USA that experienced unburned, annual or periodic (every 4 years) surface fire treatments from 1951 - 2015. Severe drought events were identified using the BILJOU water balance model. We determined the effect of fire treatment on stand-level annual growth rates as well as stand-level resistance and resilience to drought, defined as the drought-induced reduction in growth and post-drought recovery in growth, respectively. During favorable wet years, annual and periodic fire treatments reduced annual growth rates by approximately 10-15% relative to unburned controls (P < 0.001). Stand-level growth rates declined 22-40% during drought events (P < 0.001), but fire-driven changes to stand basal area had no effect on the resistance or resilience of trees to drought. The decline in annual growth rates of burned stands during favorable wet years was likely caused by increased nitrogen (N) limitation in burned plots. After 60 years of treatment, burned plots experienced 30% declines in total soil N relative to unburned plots. Our finding that drought resistance and resilience were similar across all treatments suggest that fire-driven reductions in stand density may have negligible effects on soil moisture availability during drought. Our results highlight that climate-fire interactions can have important long-term effects on forest productivity.

Effects of DanceSport on walking balance and standing balance among the elderly.

PubMed

Sohn, Jeehoon; Park, Sung-Ha; Kim, Sukwon

2018-05-04

Dancesport is a popular activity among older adults who look for fun and fitness in Korea. Studies reported positive sociological and psychological effects of dancesport. But, little studies were performed to evaluate the effects of dancesport on balance performances. The objective of the present study was to evaluate the effects of dancesport for 15 weeks on walking balance and standing balance of older adults. Older adults regularly participated in the dancesport program 3 times a week for 15 weeks. The program included Rumba, Cha-cha-cha, and Jive. They exercised the prescribed dancesport at intermediate level for 50-60 mins for each time. A total 22 reflective markers were placed on the anatomical landmarks and 8 cameras were used to measure 3-D positions of participants. Also, center of pressure (COP) data were measured to analyze standing balance using a ground reaction board at 1200 Hz for 30 seconds. One-way analysis of variance (ANOVA) was performed to test the effects of 15 weeks of dancesport on walking balance and standing balance. The results suggested that, after 15 weeks of dancesport participation, older adults' walking balance (48.3 ± 20.3 cm2 vs 38.2 ± 18.2 cm2) and standing balance (COP area: 189.4 ± 85.4 mm2 vs 103.5 ± 55.4mm2, COP distance: 84.2 ± 34.4 cm vs 76.5 ± 21.4 cm) were significantly improved. Performing dancesport would require moving center of mass rapidly and frequently while maintaining posture. This may result in improving walking balance and standing balance in the present study. The study concluded that dancesport would be an effective exercise method in enhancing postural stability of older adults.

Effect of wildfire and fireline construction on the annual depth of thaw in a black spruce permafrost forest in interior Alaska: a 36-year record of recovery

Treesearch

Leslie A. Viereck; Nancy R. Werdin-Pfisterer; Phyllis C. Adams; Kenji Yoshikawa

2008-01-01

Maximum thaw depths were measured annually in an unburned stand, a heavily burned stand, and a fireline in and adjacent to the 1971 Wickersham fire. Maximum thaw in the unburned black spruce stand ranged from 36 to 52 cm. In the burned stand, thaw increased each year to a maximum depth of 302 cm in 1995. In 1996, the entire layer of seasonal frost remained, creating a...

Longer-term effects of selective thinning on carabid beetles and spiders in the Cascade Mountains of southern Oregon

USGS Publications Warehouse

Peck, R.; Niwa, C.G.

2005-01-01

Within late-successional forests of the Cascade Mountains of southern Oregon, abundances of carabid beetles (Carabidae) and spiders (Araneae) from pitfall traps were compared between stands thinned 16-41 years prior and nearby unthinned stands. Species richness of both taxa were moderate for coniferous forests of this region, with 12 carabid beetle species and >120 spider species collected. No differences in total abundance or species richness were found between stand types for carabid beetles, although abundances of four of the six most common species differed significantly. Pterostichus setosus, the most abundant species collected, was significantly more abundant in unthinned stands, while Omus cazieri, P. lama, and Carabus taedatus were more numerous in thinned stands. In contrast, both total spider abundance and species richness were significantly higher in thinned stands. Hunting spiders within the families Lycosidae and Gnaphosidae, and the funnel web-building Dictynidae were captured more often in thinned stands while sheet web spiders within Linyphiidae and Hahniidae were more abundant in unthinned stands. The forest floor within unthinned stands was structurally more diverse than in thinned stands, but this did not lead to greater overall abundance or diversity of either carabid beetles or spiders.

I'm still standing: A longitudinal study on the effect of a default nudge.

PubMed

Venema, Tina A G; Kroese, Floor M; De Ridder, Denise T D

2018-05-01

This study assessed the effect of a default nudge to reduce sedentary behaviour at work over time. A field study was conducted at a governmental organisation. In the present study, the default setting of sit-stand desks (SSDs) was changed from sitting to standing height during a two-week intervention. Stand-up working rates were calculated based on observations that were done prior to, during, two weeks after and two months after the intervention. Additionally, a pre-measure survey (n = 606) and post-measure survey (n = 354) were completed. Intention and social norms concerning stand-up working were compared for the 183 employees who completed both pre- and post-assessments (45.4% female, M age  = 44.21). Stand-up working rates raised from 1.82% in the baseline to 13.13% during the intervention. After the nudge was removed the percentage was 10.01% after two weeks and 7.78% after two months. A multilevel analysis indicated a significant increase in both intention and social norms after the nudge intervention. This study shows that a default nudge can increase stand-up working rates in offices with SSDs at least until two months after the nudge intervention.

Effectiveness of droxidopa compared to midodrine in standing blood pressure and orthostatic tolerance in adults with neurogenic orthostatic hypotension: a systematic review protocol.

PubMed

Patrick, Kelli; Martin, Tina

2017-09-01

The question of this review is: what is the effectiveness of droxidopa compared to midodrine on standing blood pressure and orthostatic intolerance symptoms in adults with neurogenic orthostatic hypotension?

Stand Up Comics: Instructional Humor and Student Engagment

ERIC Educational Resources Information Center

Wortley, Amy; Dotson, Elizabeth

2016-01-01

This paper examines the use of instructional humor in higher education settings and makes connections between the levels of student achievement in academics and the influence of appropriate instructional humor. The work of prominent researchers such as Wanzer, Frymier, and Irwin (2010), and Segrist & Hupp (2015), who postulate that…

Miniature inverted-repeat transposable element identification and genetic marker development in Agrostis

USDA-ARS?s Scientific Manuscript database

Creeping bentgrass (Agrostis stolonifera L.) is an important species to the turfgrass industry because of its adaptation for use in high quality turf stands such as golf course putting greens, tees, and fairways. A. stolonifera is a highly outcrossing allotetraploid making genetic marker developmen...

Confessions of a Prep School College Counselor.

ERIC Educational Resources Information Center

Flanagan, Caitlin

2001-01-01

Looks at books about college admissions, and at the unexamined prejudices fueling the elite college admissions frenzy. Powerful emotions, of students and parents alike, get mixed up in the college admissions process. Class anxiety, culture wars and other prejudices, not academic standing or faculty credentials, all contribute to making some…

45 CFR 2400.60 - Renewal of award.

Code of Federal Regulations, 2014 CFR

2014-10-01

... submitted all required documentation and are making satisfactory academic progress, it is the intent of the... an annual review by the Foundation and certification by an authorized official of the university at... good academic standing according to the standards of each university. (c) As a condition of renewal of...

45 CFR 2400.60 - Renewal of award.

Code of Federal Regulations, 2013 CFR

2013-10-01

... submitted all required documentation and are making satisfactory academic progress, it is the intent of the... an annual review by the Foundation and certification by an authorized official of the university at... good academic standing according to the standards of each university. (c) As a condition of renewal of...

7 CFR 1410.40 - Cost-share payments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... such contract. (g) CCC may make cost-share payments for thinning of existing tree stands to benefit... 7 Agriculture 10 2010-01-01 2010-01-01 false Cost-share payments. 1410.40 Section 1410.40... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS CONSERVATION RESERVE PROGRAM § 1410.40 Cost...

Drugs and Crime: An Empirically Based, Interdisciplinary Model

ERIC Educational Resources Information Center

Quinn, James F.; Sneed, Zach

2008-01-01

This article synthesizes neuroscience findings with long-standing criminological models and data into a comprehensive explanation of the relationship between drug use and crime. The innate factors that make some people vulnerable to drug use are conceptually similar to those that predict criminality, supporting a spurious reciprocal model of the…

Find Your Image between the Extremes

ERIC Educational Resources Information Center

Gordon, Rachel Singer

2004-01-01

Librarians' unfortunate fixation on image as a defining generational characteristic also makes them just as guilty of promoting misconceptions as nonlibrarians. Can the profession stand another article in the general press that trumpets the amazing new discovery that librarians can be young, trendy, stylish? The level of our colleagues'…

Sniffing out the Secret Poison: Selection Bias in Educational Research

ERIC Educational Resources Information Center

Showalter, Daniel A.; Mullet, Luke B.

2017-01-01

Selection bias is a persistent, and often hidden, problem in educational research. It is the primary obstacle standing in between increasingly available large education datasets and the ability to make valid causal inferences to inform policymaking, research, and practice (Stuart, 2010). This article provides an accessible discussion on the…

75 FR 81971 - Gulf of Mexico Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-29

..., Special Spiny Lobster and Special Reef Fish Scientific and Statistical Committees. DATES: The meeting will.... During the first day of the meeting, the Standing and Special Spiny Lobster Scientific and Statistical Committees will meet jointly to review a spiny lobster update assessment and make recommendations to the...

The Diversity Project: An Ethnography of Social Justice Experiential Education Programming

ERIC Educational Resources Information Center

Vernon, Franklin

2016-01-01

Whilst adventure-based experiential education traditions have long-standing claims of progressive, democratic learning potential, little research has examined practice from within democratic theories of participation and learning. Focusing on a complex network making up a disturbing interaction in an outdoor education programme, I posit forms of…

Professional Connections through the Technology Learning Community

ERIC Educational Resources Information Center

Ancar, LeQuetia N.; Freeman, Steven A.; Field, Dennis W.

2007-01-01

A learning community is a relatively old phenomenon that has resurfaced; it is making educators at institutions of higher education stand up and take notice. Grounded in collaborative and cooperative learning theories, learning communities have created environments in which student learning is the center of attention. The social construction of…

Increasing Medical Student Numbers in England, 2001. Report.

ERIC Educational Resources Information Center

Higher Education Funding Council for England, Bristol.

This report provides information on the further allocation of additional medical student numbers in England from 2001-2002 and explains the decision making process underpinning these allocations. A report by the Medical Workforce Standing Advisory Committee in December 1997 concluded that a substantial increase in medical school intakes was…

X-34 40K Fastrac II Engine Test

NASA Technical Reports Server (NTRS)

1997-01-01

This is a photo of an X-34 40K Fastrac II duration test performed at the Marshall Space Flight Center test stand 116 (TS116) in June 1997. Engine ignition is started with Tea-Gas which makes the start burn green. The X-34 program was cancelled in 2001.

Improvement Cutting in Bottomland Hardwoods

Treesearch

J. W. Johnson

1951-01-01

Do bottomland hardwood forests respond to improvement cuts? Do growth rate and stand quality increase enough to make up for the extra effort and, sometimes, outright expense of improvement cutting? Ten years of growth on some plots on the Delta Experimental Forest near Stoneville, Mississippi, indicates that the answer to both questions is "yes".

Paper Trail

ERIC Educational Resources Information Center

Gagnon, Denis

2007-01-01

Invented in 1948, electric hand dryers now are widely available in public restrooms. Given the expense of making paper, the labor involved in keeping restrooms stocked, and the waste generated from disposing paper, the use of hand dryers is an alternative for school and university facility owners and managers. However, standing in the way of…

NRC visit

NASA Image and Video Library

2012-08-22

Four members of the National Research Council visited Stennis Space Center on Aug. 22, touring test stands and facilities, and holding roundtable discussions with Stennis leaders. The NRC mission is to improve government decision making and public policy, increase public understanding, and promote the acquisition and dissemination of knowledge in matters involving science, engineering, technology and health.

On Symbolic Significance of Characters in "Lord of the Flies"

ERIC Educational Resources Information Center

Li, Xiaofang; Wu, Weihua

2009-01-01

The characters in "Lord of the Flies" possess recognizable symbolic significance, which make them as the sort of people around us. Ralph stands for civilization and democracy; Piggy represents intellect and rationalism; Jack signifies savagery and dictatorship; Simon is the incarnation of goodness and saintliness. All of these…

76 FR 590 - Adjustment or Determination of Compulsory License Rates for Making and Distributing Phonorecords

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-05

... LIBRARY OF CONGRESS Copyright Royalty Board [Docket No. 2011-3 CRB Phonorecords II] Adjustment or... Board, Library of Congress. ACTION: Notice announcing commencement of proceeding with request for... proceeding was captioned as ``DPRA'' (which stands for ``Digital Phonorecord Rate Adjustment''). Hereinafter...

The Double Helix Takes the Witness Stand: Behavioral and Neuropsychiatric Genetics in Court

PubMed Central

Appelbaum, Paul S.

2014-01-01

Summary Data on neuropsychiatric and behavioral genetics have attracted legal interest, as attorneys explore their use in criminal and civil cases. These developments may assist judges and juries in making difficult judgments—but they bring substantial risk of misinterpretation and misuse. PMID:24908480

SOLIDIFICATION/STABILIZATION FOR REMEDIATON OF WOOD PRESERVING SITES: TREATMENT FOR DIOXINS, PCP, CREOSOTE, AND METALS

EPA Science Inventory

This article discusses the use of solidification/stabilization (S/S) to treat soils contaminated with organic and inorganic chemicals at wood preserving sites. Solidification is defined for this article as making a material into a free standing solid. Stabilization is defined as ...

A Loblolly Pine Management Guide: Natural Regeneration of Loblolly Pine

Treesearch

M. Boyd Edwards

1987-01-01

For many landowners, low cost makes natural regeneration an attractive alternative to planting when loblolly pine stands are harvested. Clearcutting, seed-tree, shelterwood, and selection methods can be used. Keys to success are a suitable seedbed.an adequate seed supply, sufficient moisture. and freedom from excessive competition.

Orthostatic function during a stand test before and after head-up or head-down bedrest

NASA Technical Reports Server (NTRS)

Lathers, Claire M.; Diamandis, Peter H.; Riddle, Jeanne M.; Mukai, Chiaki; Elton, Kay F.; Bungo, Michael W.; Charles, John B.

1991-01-01

The effects of head-down or head-up bedrest at -5, +10, +20, or +42 deg (simulating 0, 1/6, 1/3, and 2/3 g, respectively) for 6 hrs on four different days on the orthostatic tolerance were investigated by measuring relevant physiological reactions to orthostatic test taken before and after bedrest sessions. The multivariate analysis of variance statistical analyses indicates that there was no angle effect on any of the cardiovascular parameters monitored during the last 3 min of the stand test, suggesting that partial gravity loads would have no effect on the cardiovascular deconditioning exhibited postflight. There was, however, a significant elevation in the heart rate post-bedrest, and the heart rate increased on standing. Results from the stand test pre- and post-bedrest at -5 deg (but not at +10, +20, and +42 deg) were similar to those observed after space flight.

Additive or non-additive effect of mixing oak in pine stands on soil properties depends on the tree species in Mediterranean forests.

PubMed

Brunel, Caroline; Gros, Raphael; Ziarelli, Fabio; Farnet Da Silva, Anne Marie

2017-07-15

This study investigated how oak abundance in pine stands (using relative Oak Basal Area %, OBA%) may modulate soil microbial functioning. Forests were composed of sclerophyllous species i.e. Quercus ilex mixed with Pinus halepensis Miller or of Q. pubescens mixed with P. sylvestris. We used a series of plots with OBA% ranging from 0 to 100% in the two types of stand (n=60) and both OLF and A-horizon compartments were analysed. Relations between OBA% and either soil chemical (C and N contents, quality of organic matter via solid-state NMR, pH, CaCO 3 ) or microbial (enzyme activities, basal respiration, biomass and catabolic diversity via BIOLOG) characteristics were described. OBA% increase led to a decrease in the recalcitrant fraction of organic matter (OM) in OLF and promoted microbial growth. Catabolic profiles of microbial communities from A-horizon were significantly modulated in Q. ilex and P. halepensis stand by OBA% and alkyl C to carboxyl C ratio (characteristic of cutin from Q. ilex tissues) and in Q. pubescens and P. sylvestris stands, by OBA% and pH. In A-horizon under Q. ilex and P. halepensis stands, linear regressions were found between catabolic diversity, microbial biomass and OBA% suggesting an additive effect. Conversely, in A-horizon Q. pubescens and P. sylvestris stands, the relationship between OBA% and either cellulase activities, polysaccharides or ammonium contents, suggested a non-additive effect of Q. pubescens and P. sylvestris, enhancing mineralization of the OM labile fraction for plots characterized by an OBA% ranging from 40% to 60%. Mixing oak with pine thus favored microbial dynamics in both type of stands though OBA% print varied with tree species and consequently sustainable soil functioning depend strongly on the composition of mixed stands. Our study indeed revealed that, when evaluating the benefits of forest mixed stand on soil microbial functioning and OM turnover, the identity of tree species has to be considered. Copyright © 2017 Elsevier B.V. All rights reserved.

The effectiveness of stand alone air cleaners for shelter-in-place.

PubMed

Ward, M; Siegel, J A; Corsi, R L

2005-04-01

Stand-alone air cleaners may be efficient for rapid removal of indoor fine particles and have potential use for shelter-in-place (SIP) strategies following acts of bioterrorism. A screening model was employed to ascertain the potential significance of size-resolved particle (0.1-2 microm) removal using portable high efficiency particle arresting (HEPA) air cleaners in residential buildings following an outdoor release of particles. The number of stand-alone air cleaners, air exchange rate, volumetric flow rate through the heating, ventilating and air-conditioning (HVAC) system, and size-resolved particle removal efficiency in the HVAC filter were varied. The effectiveness of air cleaners for SIP was evaluated in terms of the outdoor and the indoor particle concentration with air cleaner(s) relative to the indoor concentration without air cleaners. Through transient and steady-state analysis of the model it was determined that one to three portable HEPA air cleaners can be effective for SIP following outdoor bioaerosol releases, with maximum reductions in particle concentrations as high as 90% relative to conditions in which an air cleaner is not employed. The relative effectiveness of HEPA air cleaners vs. other removal mechanisms was predicted to decrease with increasing particle size, because of increasing competition by particle deposition with indoor surfaces and removal to HVAC filters. However, the effect of particle size was relatively small for most scenarios considered here. The results of a screening analysis suggest that stand-alone (portable) air cleaners that contain high efficiency particle arresting (HEPA) filters can be effective for reducing indoor fine particle concentrations in residential dwellings during outdoor releases of biological warfare agents. The relative effectiveness of stand-alone air cleaners for reducing occupants' exposure to particles of outdoor origin depends on several factors, including the type of heating, ventilating and air-conditioning (HVAC) filter, HVAC operation, building air exchange rate, particle size, and duration of elevated outdoor particle concentration. Maximum particle reductions, relative to no stand-alone air cleaners, of 90% are predicted when three stand-alone air cleaners are employed.

Carbon footprint of forest and tree utilization technologies in life cycle approach

NASA Astrophysics Data System (ADS)

Polgár, András; Pécsinger, Judit

2017-04-01

In our research project a suitable method has been developed related the technological aspect of the environmental assessment of land use changes caused by climate change. We have prepared an eco-balance (environmental inventory) to the environmental effects classification in life-cycle approach in connection with the typical agricultural / forest and tree utilization technologies. The use of balances and environmental classification makes possible to compare land-use technologies and their environmental effects per common functional unit. In order to test our environmental analysis model, we carried out surveys in sample of forest stands. We set up an eco-balance of the working systems of intermediate cutting and final harvest in the stands of beech, oak, spruce, acacia, poplar and short rotation energy plantations (willow, poplar). We set up the life-cycle plan of the surveyed working systems by using the GaBi 6.0 Professional software and carried out midpoint and endpoint impact assessment. Out of the results, we applied the values of CML 2001 - Global Warming Potential (GWP 100 years) [kg CO2-Equiv.] and Eco-Indicator 99 - Human health, Climate Change [DALY]. On the basis of the values we set up a ranking of technology. By this, we received the environmental impact classification of the technologies based on carbon footprint. The working systems had the greatest impact on global warming (GWP 100 years) throughout their whole life cycle. This is explained by the amount of carbon dioxide releasing to the atmosphere resulting from the fuel of the technologies. Abiotic depletion (ADP foss) and marine aquatic ecotoxicity (MAETP) emerged also as significant impact categories. These impact categories can be explained by the share of input of fuel and lube. On the basis of the most significant environmental impact category (carbon footprint), we perform the relative life cycle contribution and ranking of each technologies. The technological life cycle stages examined in the stands are the followings: Stage 1. cleaning cutting Stage 2. selection thinning Stage 3. increment thinning Stage 4. final harvest In these priority impact categories, the life cycle contribution of technologies varied according to the life cycle stages. • The spruce stand showed the smallest contribution in the stages 1, 2, 3 alike. • After the large contribution of beech stand at the beginning (stage 1), it continues representing a moderate level in stage 2 and 3, and it shares the smallest rate in final harvest (stage 4). • The oak stand showed the largest contribution in the stages 2, 3, 4 alike. • In the case of acacia and poplar, we have got the same results as in the case of oak stands. • In the case of short rotation energy plantations (willow, poplar), we got the results typical on stage 4 of spruce stands. We can conclude, that in case of the stage of final harvest, which represents the most significant environmental impact, the ranking of working systems showes the increasing order of „energy plantations - beech - spruce - acacia - poplar - oak". The environmental assessment of technological aspects of land use and land use change represent an important added value to the climate research. Acknowledgement: This research has been supported by the Agroclimate.2 VKSZ_12-1- 2013-0034 project. Keywords: life-cycle assessment / forest utilization technology / carbon footprint / life-cycle thinking

Effects of Standing and Light-Intensity Activity on Ambulatory Blood Pressure.

PubMed

Zeigler, Zachary S; Mullane, Sarah L; Crespo, Noe C; Buman, Matthew P; Gaesser, Glenn A

2016-02-01

This study aimed to compare ambulatory blood pressure (ABP) response to accumulated standing (STAND), cycling (CYCLE), and walking (WALK) to a sitting-only (SIT) day in adults. Nine overweight or obese (body mass index, 28.7 ± 2.7 kg · m(-2)) adults (30 ± 15 yr) participated in this randomized crossover full-factorial study. Four conditions (WALK, STAND, CYCLE, and SIT) were randomly performed 1 wk apart. WALK, STAND, and CYCLE conditions consisted of progressively increasing activity time to accumulate 2.5 h during an 8-h simulated workday. WALK (1.0 mph) and STAND (0.0 mph) were completed on a treadmill placed underneath a standing-height desk. During CYCLE, participants pedaled on a Monark cycle ergometer at a cadence and energy expenditure equivalent to WALK. Participants remained seated during the SIT condition. Participants wore an ABP cuff from 0800 h until 2200 h on all conditions. Linear mixed models were used to test condition differences in systolic (SBP) and diastolic (DBP) blood pressure. Chi-square was used to detect frequency difference of BP load. There was a whole-day (during and after work hours) SBP and DBP treatment effect (P < 0.01). Systolic blood pressure during STAND (132 ± 17 mm Hg), WALK (133 ± 17 mm Hg), and CYCLE (130 ± 16 mm Hg) were lower compared with that during SIT (137 ± 17 mm Hg) (all P < 0.01). CYCLE was lower than STAND (P = 0.04) and WALK (P < 0.01). For DBP, only CYCLE (69 ± 12 mm Hg) was lower than SIT (71 ± 13 mm Hg; P < 0.01). Compared with SIT, WALK, STAND, and CYCLE reduced SBP load by 4%, 4%, and 13%, respectively (all P < 0.01). Compared with sitting, accumulating 2.5 h of light-intensity physical activity or standing during an 8-h workday may reduce ABP during and after work hours.

Effect of thinning on height and diameter growth of oak & yellow-poplar saplings

Treesearch

Rufus H., Jr. Allen; David A. Marquis; David A. Marquis

1970-01-01

Studying the response to thinning of a 7- to 9-year-old upland hardwood sapling stand, we found that height growth of yellow-poplar and oak trees was markedly reduced by heavy thinning. This suggests that stand density should be carefully controlled to achieve maximum benefit from thinnings in very young stands.

Does nitrogen and sulfur deposition affect forest productivity?

Treesearch

Brittany A. Johnson; Kathryn B. Piatek; Mary Beth Adams; John R. Brooks

2010-01-01

We studied the effects of atmospheric nitrogen and sulfur deposition on forest productivity in a 10-year-old, aggrading forest stand at the Fernow Experimental Forest in Tucker County, WV. Forest productivity was expressed as total aboveground wood biomass, which included stem and branch weight of standing live trees. Ten years after stand regeneration and treatment...

Species-area relations of song birds in the Black Hills, South Dakota

Treesearch

Mark A. Rumble; Brian L. Dykstra; Lester D. Flake

2000-01-01

We investigated the effects of stand size resulting from current logging practices on occurrence and species richness of song birds in the Black Hills. Richness of forest interior and forest interior/edge songbirds was not related to stand area (P > 0.40) in stands of ponderosa pine (Pinus ponderosa) in the Black Hills. Brown creepers (...

It's Academic: Shelf-Ready Standing Orders at the University of Florida's Smathers Library.

ERIC Educational Resources Information Center

Crump, Michele; Carrico, Steven

2001-01-01

Describes an outsourcing project at the University of Florida library in which their supplier of domestic serial standing orders supplied a large percentage of the standing orders with complete physical processing. Discusses cost effectiveness, low error rate, and the resulting improvement in workflow efficiency that made the project a success.…

Shearing Restores Full Productivity to Sparse Aspen Stands

Treesearch

Donald A. Perala

1983-01-01

Four mature but grossly under-stocked (15 to 23 percent of normal) aspen stands were regenerated by suckering following shearing. Eight years later, aspen standing crop varied with site quality from 3.4 to 8.0 tons per acre -- nearly the potential for these sites at this age. Shearing is as effective as complete clearcutting for regenerating aspen.

Composition and development of reproduction in two-age Appalachian hardwood stands: 20-year results

Treesearch

Gary W. Miller; James N. Kochenderfer; Desta Fekedulegn

2004-01-01

In the early 1980s, silviculturists with the Northeastern Research Station and Monongahela National Forest envisioned that managing some Appalachian hardwood stands to promote two-age structures would be part of an effective strategy for managing multi-use forests. Two-age stands provided the light and seedbed conditions necessary for regenerating numerous desirable...

A case history of all-age management

Treesearch

Richard M. Godman; Gilbert A. Mattson

1992-01-01

Single-tree selection "works" in sugar maple stands in the Lake States. This system of all-age management has been used for 31 years on the Argonne Experimental Forest. In 1953, researchers found that cutting according to basal area guides is both a convenient and effective way to regulate a stand. Later experience showed that achieving good stand structure...

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...

Effects of habitat on stand productivity in the White Mountains of New Hampshire

Treesearch

William B. Leak

1979-01-01

Mean annual biomass production of sapling stands was higher on washed tills, which have a hardwood climax, than on habitats having a softwood climax. However, biomass production of poletimber stands did not differ significantly among habitats. Apparently, differences among habitats in characteristics species composition tends to mask differences in biomass productivity...

Detecting Responses of Loblolly Pine Stand Development to Site-Preparation Intensity: A Modeling Approach

Treesearch

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

1997-01-01

Data from an existing site preparation experiment in the Georgia Piedmont were subjected to a modeling approach to analyze effects of site preparation intensity on stand development of loblolly pine (Pinus taeda L.) 5 to 12 years since treatment. An average stand height model that incorporated indicator variables for treatment provided an accurate...

Competitive status influences tree-growth responses to elevated CO2 and 03 in aggrading aspen stands

Treesearch

E. P. McDonald; E. L. Kruger; D. E. Riemenschneider; J. G. Isebrands

2002-01-01

1. Competition effects on growth of individual trees were examined for 4 years in aggrading, mixed-clone stands of trembling aspen (Populus tremuloides Michx.) at the Aspen-FACE free-air Co2 and O3 enrichment facility in northern Wisconsin, USA. During each growing season stands received one of four...

Revaluation Of Wrocław Public Use Buildings In Years 2005 - 2013

NASA Astrophysics Data System (ADS)

Kirschke, Paweł

2015-09-01

In the years 2005-2013 in Wroclaw, there was commissioned to use hundreds of public buildings, including fifty revalued monuments These were: offices, museums, theatres, science and education facilities, as well as commercial buildings: banks, department stores, office buildings and hotels. The success of these projects was the merit of Wroclaw scientists who nurtured these outstanding works of architecture and convince the public to the fact that they stand for works which cannot be missed. The merit of architects and conservators was professionally prepared projects and effective supervision of investment, making the implementation of technical and program objectives not colliding with protection of historic material of the objects.

Age, task complexity, and sex as potential moderators of attentional focus effects.

PubMed

Becker, Kevin; Smith, Peter J K

2013-08-01

The study tested whether age, sex, or task complexity moderate the effect of attentional focus on motor learning. Children (24 boys, 24 girls) and adults (24 men, 24 women) were assigned to an internal or external attentional focus, and were timed while riding either a Double Pedalo with handles (simple task) or without handles (complex task) over a distance of 7 meters. A Double Pedalo is a four-wheeled device that involves standing on two connected platforms, and alternately pushing them forward to make it move. Participants completed 20 acquisition trials, followed by a 24-hour retention test. For the simpler task, no time differences due to attentional focus emerged. With the complex task, an external focus resulted in faster times in retention than an internal focus, but only for males. These findings suggest that attentional focus affects children and adults similarly, but task complexity and sex moderate these effects.

Effects of resource supplements on mature ciliate biofilms: an empirical test using a new type of flow cell.

PubMed

Norf, Helge; Arndt, Hartmut; Weitere, Markus

2009-11-01

Biofilm-dwelling consumer communities play an important role in the matter flux of many aquatic ecosystems. Due to their poor accessibility, little is as yet known about the regulation of natural biofilms. Here, a new type of flow cell is presented which facilitates both experimental manipulation and live observation of natural, pre-grown biofilms. These flow cells were used to study the dynamics of mature ciliate biofilms in response to supplementation of planktonic bacteria. The results suggest that enhanced ciliate productivity could be quickly transferred to micrometazoans (ciliate grazers), making the effects on the standing stock of the ciliates detectable only for a short time. Likewise, no effect on ciliates appeared when micrometazoan consumers were ab initio abundant. This indicates the importance of 'top-down' control of natural ciliate biofilms. The flow cells used here offer great potential for experimentally testing such control mechanisms within naturally cultivated biofilms.

Photovoltaic concepts inspired by coherence effects in photosynthetic systems

NASA Astrophysics Data System (ADS)

Brédas, Jean-Luc; Sargent, Edward H.; Scholes, Gregory D.

2017-01-01

The past decade has seen rapid advances in our understanding of how coherent and vibronic phenomena in biological photosynthetic systems aid in the efficient transport of energy from light-harvesting antennas to photosynthetic reaction centres. Such coherence effects suggest strategies to increase transport lengths even in the presence of structural disorder. Here we explore how these principles could be exploited in making improved solar cells. We investigate in depth the case of organic materials, systems in which energy and charge transport stand to be improved by overcoming challenges that arise from the effects of static and dynamic disorder -- structural and energetic -- and from inherently strong electron-vibration couplings. We discuss how solar-cell device architectures can evolve to use coherence-exploiting materials, and we speculate as to the prospects for a coherent energy conversion system. We conclude with a survey of the impacts of coherence and bioinspiration on diverse solar-energy harvesting solutions, including artificial photosynthetic systems.

Postural effects on the noninvasive baselines of ventricular performance

NASA Technical Reports Server (NTRS)

Lance, V. Q.; Spodick, D. H.

1977-01-01

The effects of posture on time-based noninvasive measurements were determined utilizing the sequence supine-sitting-standing in a formal protocol in which observer biases were eliminated by blinding the measurement and calculation phases. Compared to the supine posture, the sitting and standing postures produced significant increases in heart rate, isovolumic contraction time, pre-ejection period and pre-ejection period/left-ventricular ejection time and significant decreases in ejection time and ejection time index. The response patterns are consistent with the hemodynamic correlates cited in the literature which show increased adrenergic activity and decreased venous return in the sitting and standing postures, the effect on venous return being dominant.

Effects of Short-Term Isokinetic Training on Standing Long-Jump Performance in Untrained Men.

ERIC Educational Resources Information Center

Morriss, Calvin J.; Tolfrey, Keith; Coppack, Russell J.

2001-01-01

Evaluated the effects of a brief isokinetic training program on quadriceps and hamstring peak torque (PT) and standing long-jump performance. Tests on 12 untrained men indicated that the brief training program was at least as effective in improving quadriceps isokinetic (but not hamstring) PT. PT gains subsequent to isokinetic resistance training…

Effects of alternative treatments on canopy fuel characteristics in five conifer stands

Treesearch

Joe H. Scott; Elizabeth D. Reinhardt

2007-01-01

A detailed study of canopy fuel characteristics in five different forest types provided a unique dataset for simulating the effects of various stand manipulation treatments on canopy fuels. Low thinning, low thinning with commercial dbh limit, and crown thinning had similar effects on canopy bulk density (CBD) and canopy fuel load (CFL...

Processing Pipeline of Sugarcane Spectral Response to Characterize the Fallen Plants Phenomenon

NASA Astrophysics Data System (ADS)

Solano, Agustín; Kemerer, Alejandra; Hadad, Alejandro

2016-04-01

Nowadays, in agronomic systems it is possible to make a variable management of inputs to improve the efficiency of agronomic industry and optimize the logistics of the harvesting process. In this way, it was proposed for sugarcane culture the use of remote sensing tools and computational methods to identify useful areas in the cultivated lands. The objective was to use these areas to make variable management of the crop. When at the moment of harvesting the sugarcane there are fallen stalks, together with them some strange material (vegetal or mineral) is collected. This strange material is not millable and when it enters onto the sugar mill it causes important looses of efficiency in the sugar extraction processes and affects its quality. Considering this issue, the spectral response of sugarcane plants in aerial multispectral images was studied. The spectral response was analyzed in different bands of the electromagnetic spectrum. Then, the aerial images were segmented to obtain homogeneous regions useful for producers to make decisions related to the use of inputs and resources according to the variability of the system (existence of fallen cane and standing cane). The obtained segmentation results were satisfactory. It was possible to identify regions with fallen cane and regions with standing cane with high precision rates.

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

Adam, J. C.; Stephens, J. C.; Chung, Serena

As managers of agricultural and natural resources are confronted with uncertainties in global change impacts, the complexities associated with the interconnected cycling of nitrogen, carbon, and water present daunting management challenges. Existing models provide detailed information on specific sub-systems (land, air, water, economics, etc). An increasing awareness of the unintended consequences of management decisions resulting from interconnectedness of these sub-systems, however, necessitates coupled regional earth system models (EaSMs). Decision makers’ needs and priorities can be integrated into the model design and development processes to enhance decision-making relevance and "usability" of EaSMs. BioEarth is a current research initiative with a focusmore » on the U.S. Pacific Northwest region that explores the coupling of multiple stand-alone EaSMs to generate usable information for resource decision-making. Direct engagement between model developers and non-academic stakeholders involved in resource and environmental management decisions throughout the model development process is a critical component of this effort. BioEarth utilizes a "bottom-up" approach, upscaling a catchment-scale model to basin and regional scales, as opposed to the "top-down" approach of downscaling global models utilized by most other EaSM efforts. This paper describes the BioEarth initiative and highlights opportunities and challenges associated with coupling multiple stand-alone models to generate usable information for agricultural and natural resource decision-making.« less

Three-dimensional cavity nanoantennas with resonant-enhanced surface plasmons as dynamic color-tuning reflectors.

PubMed

Fan, J R; Wu, W G; Chen, Z J; Zhu, J; Li, J

2017-03-09

As plasmonic antennas for surface-plasmon-assisted control of optical fields at specific frequencies, metallic nanostructures have recently emerged as crucial optical components for fascinating plasmonic color engineering. Particularly, plasmonic resonant nanocavities can concentrate lightwave energy to strongly enhance light-matter interactions, making them ideal candidates as optical elements for fine-tuning color displays. Inspired by the color mixing effect found on butterfly wings, a new type of plasmonic, multiresonant, narrow-band (the minimum is about 45 nm), high-reflectance (the maximum is about 95%), and dynamic color-tuning reflector is developed. This is achieved from periodic patterns of plasmonic resonant nanocavities in free-standing capped-pillar nanostructure arrays. Such cavity-coupling structures exhibit multiple narrow-band selective and continuously tunable reflections via plasmon standing-wave resonances. Consequently, they can produce a variety of dark-field vibrant reflective colors with good quality, strong color signal and fine tonal variation at the optical diffraction limit. This proposed multicolor scheme provides an elegant strategy for realizing personalized and customized applications in ultracompact photonic data storage and steganography, colorimetric sensing, 3D holograms and other plasmon-assisted photonic devices.

The effect of viewing a virtual environment through a head-mounted display on balance.

PubMed

Robert, Maxime T; Ballaz, Laurent; Lemay, Martin

2016-07-01

In the next few years, several head-mounted displays (HMD) will be publicly released making virtual reality more accessible. HMD are expected to be widely popular at home for gaming but also in clinical settings, notably for training and rehabilitation. HMD can be used in both seated and standing positions; however, presently, the impact of HMD on balance remains largely unknown. It is therefore crucial to examine the impact of viewing a virtual environment through a HMD on standing balance. To compare static and dynamic balance in a virtual environment perceived through a HMD and the physical environment. The visual representation of the virtual environment was based on filmed image of the physical environment and was therefore highly similar. This is an observational study in healthy adults. No significant difference was observed between the two environments for static balance. However, dynamic balance was more perturbed in the virtual environment when compared to that of the physical environment. HMD should be used with caution because of its detrimental impact on dynamic balance. Sensorimotor conflict possibly explains the impact of HMD on balance. Copyright © 2016 Elsevier B.V. All rights reserved.

The Canadian SSRMS is moved to test stand in the SSPF

NASA Technical Reports Server (NTRS)

2000-01-01

Workers in the Space Station Processing Facility help guide the Canadian Space Agency's Space Station Remote Manipulator System (SSRMS) suspended from an overhead crane. The SSRMS is being moved to a test stand where it will be mated to its payload carrier. This pallet will later be installed into the payload bay of Space Shuttle Endeavour for launch to the International Space Station on STS-100 in April 2001. The 56-foot-long arm will be the primary means of transferring payloads between the orbiter payload bay and the Station. Its three segments comprise seven joints for highly flexible land precise movement, making it capable of moving around the Station's exterior like an inchworm.

Analysis of Operating Modes of Stand-Alone Series Controller of Power Flows for Overhead Power Transmission Lines

NASA Astrophysics Data System (ADS)

Astashev, M. G.; Panfilov, D. I.; Seregin, D. A.; Chernyshev, A. A.

2017-12-01

The features of using the bridge voltage inverter in small-size stand-alone series controllers of power flows (PFSC) for overhead power transmission lines (OPTL) are examined. The basic processes in the converter during transient and steady state modes were analyzed. The basic relations for calculating the electromagnetic processes taking into account the energy loss in the circuit and without it were received. A simulation model is proposed of a converter that makes it possible to study its operating modes during the formation of reactance introduced into the overhead power transmission line. The results of simulation of operating modes of the PFSC are presented.

Space Shuttle Projects

NASA Image and Video Library

1991-07-01

This photograph shows the Solid Propellant Test Article (SPTA) test stand with the Modified Nasa Motor (M-NASA) test article at the Marshall Space Flight Center (MSFC). The SPTA test stand, 12-feet wide by 12-feet long by 24-feet high, was built in 1989 to provide comparative performance data on nozzle and case insulation material and to verify thermostructural analysis models. A modified NASA 48-inch solid motor (M-NASA motor) with a 12-foot blast tube and 10-inch throat makes up the SPTA. The M-NASA motor is being used to evaluate solid rocket motor internal non-asbestos insulation materials, nozzle designs, materials, and new inspection techniques. New internal motor case instrumentation techniques are also being evaluated.

Hybrid Rocket Experiment Station for Capstone Design

NASA Technical Reports Server (NTRS)

Conley, Edgar; Hull, Bethanne J.

2012-01-01

Portable hybrid rocket motors and test stands can be seen in many papers but none have been reported on the design or instrumentation at such a small magnitude. The design of this hybrid rocket and test stand is to be small and portable (suitcase size). This basic apparatus will be used for demonstrations in rocket propulsion. The design had to include all of the needed hardware to operate the hybrid rocket unit (with the exception of the external Oxygen tank). The design of this project includes making the correlation between the rocket's thrust and its size, the appropriate transducers (physical size, resolution, range, and cost), compatability with a laptop analog card, the ease of setup, and its portability.

The ACT transport: Panacea for the 80's or designer's illusion (panel discussion)

NASA Technical Reports Server (NTRS)

1976-01-01

A panel discussion was held which attempted to make an objective and pragmatic assessment of the standing of active control technology. The discussion focused on the standing of active control technology relative to civil air transport applications, the value as opposed to the cost of the projected benefits, the need for research, development, and demonstration, the role of government and industry in developing the technology, the major obstacles to its implementation, and the probable timing of the full utilization of active control technology in commercial transportation. An edited transcription of the prepared statements of the panel members and the subsequent open discussion between the panel and the audience is presented.

Vertical gradients and seasonal variation in stem CO2 efflux within a Norway spruce stand.

PubMed

Tarvainen, Lasse; Räntfors, Mats; Wallin, Göran

2014-05-01

Stem CO2 efflux is known to vary seasonally and vertically along tree stems. However, annual tree- and stand-scale efflux estimates are commonly based on measurements made only a few times a year, during daytime and at breast height. In this study, the effect of these simplifying assumptions on annual efflux estimates and their influence on the estimates of the importance of stems in stand-scale carbon cycling are evaluated. In order to assess the strength of seasonal, diurnal and along-stem variability in CO2 efflux, half-hourly measurements were carried out at three heights on three mature Norway spruce (Picea abies (L.) Karst.) trees over a period of 3 years. Making the common assumption of breast height efflux rates being representative of the entire stem was found to result in underestimations of 10-17% in the annual tree-scale CO2 efflux. Upscaling using only daytime measurements from breast height increased the underestimation to 15-20%. Furthermore, the results show that the strength of the vertical gradient varies seasonally, being strongest in the early summer and non-existent during the cool months. The observed seasonality in the vertical CO2 efflux gradient could not be explained by variation in stem temperature, temperature response of the CO2 efflux (Q10), outer-bark permeability, CO2 transport in the xylem or CO2 release from the phloem. However, the estimated CO2 concentration immediately beneath the bark was considerably higher in the upper stem during the main period of diameter growth, coinciding with the strongest vertical efflux gradient. These results suggest that higher growth rates in the upper stem are the main cause for the observed vertical variation in the stem CO2 effluxes. Furthermore, the results indicate that accounting for the vertical efflux variation is essential for assessments of the importance of stems in stand-scale carbon cycling. © The Author 2014. Published by Oxford University Press. All rights reserved.

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...

Evaporation and transpiration from forests in Central Europe - relevance of patch-level studies for spatial scaling

NASA Astrophysics Data System (ADS)

Köstner, B.

Spatial scaling from patch to the landscape level requires knowledge on the effects of vegetation structure on maximum surface conductances and evaporation rates. The following paper summarizes results on atmospheric, edaphic, and structural controls on forest evaporation and transpiration observed in stands of Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and European beech (Fagus sylvatica). Forest canopy transpiration (Ec) was determined by tree sapflow measurements scaled to the stand level. Estimates of understory transpiration and forest floor evaporation were derived from lysimeter and chamber measurements. Strong reduction of Ec due to soil drought was only observed at a Scots pine stand when soil water content dropped below 16% v/v. Although relative responses of Ec on atmospheric conditions were similar, daily maximum rates of could differ more than 100% between forest patches of different structure (1.5-3.0mmd-1 and 2.6-6.4mmd-1 for spruce and beech, respectively). A significant decrease of Ecmax per leaf area index with increasing stand age was found for monocultures of Norway spruce, whereas no pronounced changes in were observed for beech stands. It is concluded that structural effects on Ecmax can be specified and must be considered for spatial scaling from forest stands to landscapes. Hereby, in conjunction with LAI, age-related structural parameters are important for Norway spruce stands. Although compensating effects of tree canopy layers and understory on total evaporation of forests were observed, more information is needed to quantify structure-function relationships in forests of heterogenous structure.

Cost effectiveness of a community-based crisis intervention program for people bereaved by suicide.

PubMed

Comans, Tracy; Visser, Victoria; Scuffham, Paul

2013-01-01

Postvention services aim to ameliorate distress and reduce future incidences of suicide. The StandBy Response Service is one such service operating in Australia for those bereaved through suicide. Few previous studies have reported estimates or evaluations of the economic impact and outcomes associated with the implementation of bereavement/grief interventions. To estimate the cost-effectiveness of a postvention service from a societal perspective. A Markov model was constructed to estimate the health outcomes, quality-adjusted life years, and associated costs such as medical costs and time off work. Data were obtained from a prospective cross-sectional study comparing previous clients of the StandBy service with a control group of people bereaved by suicide who had not had contact with StandBy. Costs and outcomes were measured at 1 year after suicide bereavement and an incremental cost-effectiveness ratio was calculated. The base case found that the StandBy service dominated usual care with a cost saving from providing the StandBy service of AUS $803 and an increase in quality-adjusted life years of 0.02. Probabilistic sensitivity analysis indicates there is an 81% chance the service would be cost-effective given a range of possible scenarios. Postvention services are a cost-effective strategy and may even be cost-saving if all costs to society from suicide are taken into account.

Generation of uniform large-area very high frequency plasmas by launching two specific standing waves simultaneously

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

Chen, Hsin-Liang, E-mail: hlchen@iner.gov.tw; Tu, Yen-Cheng; Hsieh, Cheng-Chang

2014-09-14

With the characteristics of higher electron density and lower ion bombardment energy, large-area VHF (very high frequency) plasma enhanced chemical vapor deposition has become an essential manufacturing equipment to improve the production throughput and efficiency of thin film silicon solar cell. However, the combination of high frequency and large electrodes leads to the so-called standing wave effect causing a serious problem for the deposition uniformity of silicon thin film. In order to address this issue, a technique based on the idea of simultaneously launching two standing waves that possess similar amplitudes and are out of phase by 90° in timemore » and space is proposed in this study. A linear plasma reactor with discharge length of 54 cm is tested with two different frequencies including 60 and 80 MHz. The experimental results show that the proposed technique could effectively improve the non-uniformity of VHF plasmas from >±60% when only one standing wave is applied to <±10% once two specific standing waves are launched at the same time. Moreover, in terms of the reactor configuration adopted in this study, in which the standing wave effect along the much shorter dimension can be ignored, the proposed technique is applicable to different frequencies without the need to alter the number and arrangement of power feeding points.« less

Design and Evaluation of a Stand-Up Motorized Prone Cart

PubMed Central

Harrow, Jeffrey J; Malassigné, Pascal; Nelson, Audrey L; Jensen, Robert P; Amato, Margaret; Palacios, Polly L

2007-01-01

Background/Objective: Prone carts are used for mobility by individuals with spinal cord injury in whom seated mobility (wheelchair) is contraindicated due to ischial or sacral pressure ulcers. Currently available prone carts are uncomfortable, subjecting the user to neck and shoulder strain, and make social interaction and performing activities of daily living difficult. A better design of prone carts is needed. In addition, standing devices have shown some medical benefits. The objective was to design and evaluate an improved prone cart that facilitates standing. Design: Engineering development project with user feedback through questionnaire. Users selected by convenience sampling. Methods: A marketing survey was performed of nurse managers of spinal cord injury units. Then 2 prototype carts were designed and built. These carts are able to tilt up to 45° and have a joystick-controlled motor for propulsion and other design features, including a workspace storage shelf and rearview mirrors. The carts were evaluated by both patients and caregivers at 2 Veteran's Administration hospitals. Outcome Measures: Questionnaire of subjects, both patients and caregivers, who used the cart. Findings: Both patients and caregivers liked the carts and the ability to assume a nonhorizontal body angle. The major complaint about the cart was that it seemed too long when it came to making turns. Conclusion: This prone cart design is an improvement over the standard, flat variety. However, further design changes will be necessary. This study provided valuable information that will be useful in the next-generation prone cart design project. PMID:17385270

[Population structure of soil arthropod in different age Pinus massoniana plantations].

PubMed

Tan, Bo; Wu, Fu-zhong; Yang, Wan-qin; Zhang, Jian; Xu, Zhen-feng; Liu, Yang; Gou, Xiao-lin

2013-04-01

An investigation was conducted on the population structure of soil arthropod community in the 3-, 8-, 14-, 31-, and 40-years old Pinus massoniana plantations in the upper reaches of the Yangtze River in spring (May) and autumn (October), 2011, aimed to search for the scientific management of the plantation. A total of 4045 soil arthropods were collected, belonging to 57 families. Both the individual density and the taxonomic group number of the soil arthropod community decreased obviously with increasing soil depth, and this trend increased with increasing stand age. The dominant groups and ordinary groups of the soil arthropod community varied greatly with the stand age of P. massoniana plantation, and a significant difference (P<0.05) was observed in the individual density and taxonomic group number among different age P. massoniana plantations. In comparison with other stand age P. massoniana plantations, 3years old P. massoniana plantation had a significant difference in the structure and diversity of soil arthropod community, and the similarity index of the soil arthropod community was lower. The individual density, taxonomic group number, and diversity of soil arthropod community were the highest in 8-years old P. massoniana plantation, and then, decreased obviously with increasing stand age. It was suggested that the land fertility of the P. massoniana plantations could be degraded with increasing stand age, and it would be appropriate to make artificial regulation and restoration in 8-years old P. massoniana plantation.

Across a macro-ecological gradient forest competition is strongest at the most productive sites

PubMed Central

Prior, Lynda D.; Bowman, David M. J. S.

2014-01-01

We tested the hypothesis that the effect of forest basal area on tree growth interacts with macro-ecological gradients of primary productivity, using a large dataset of eucalypt tree growth collected across temperate and sub- tropical mesic Australia. To do this, we derived an index of inter-tree competition based on stand basal area (stand BA) relative to the climatically determined potential basal area. Using linear mixed effects modeling, we found that the main effects of climatic productivity, tree size, and competition explained 26.5% of the deviance in individual tree growth, but adding interactions to the model could explain a further 8.9%. The effect of competition on growth interacts with the gradient of climatic productivity, with negligible effect of competition in low productivity environments, but marked negative effects at the most productive sites. We also found a positive interaction between tree size and stand BA, which was most pronounced in the most productive sites. We interpret these patterns as reflecting intense competition for light amongst maturing trees on more productive sites, and below ground moisture limitation at low productivity sites, which results in open stands with little competition for light. These trends are consistent with the life history and stand development of eucalypt forests: in cool moist environments, light is the most limiting resource, resulting in size-asymmetric competition, while in hot, low rainfall environments are open forests with little competition for light but where the amount of tree regeneration is limited by water availability. PMID:24926304

Stand dynamics of an oak woodland forest and effects of a restoration treatment on forest health

Treesearch

Stacy L. Clark; Callie J. Schweitzer

2016-01-01

Woodland restoration has been conducted in many countries, primarily in Mediterranean regions, but has only recently been attempted on publically and privately owned lands in the eastern United States. We reconstructed historical stand dynamics and tested the immediate effects of an oak

A meta-analysis of functional group responses to forest recovery outside of the tropics.

PubMed

Spake, Rebecca; Ezard, Thomas H G; Martin, Philip A; Newton, Adrian C; Doncaster, C Patrick

2015-12-01

Both active and passive forest restoration schemes are used in degraded landscapes across the world to enhance biodiversity and ecosystem service provision. Restoration is increasingly also being implemented in biodiversity offset schemes as compensation for loss of natural habitat to anthropogenic development. This has raised concerns about the value of replacing old-growth forest with plantations, motivating research on biodiversity recovery as forest stands age. Functional diversity is now advocated as a key metric for restoration success, yet it has received little analytical attention to date. We conducted a meta-analysis of 90 studies that measured differences in species richness for functional groups of fungi, lichens, and beetles between old-growth control and planted or secondary treatment forests in temperate, boreal, and Mediterranean regions. We identified functional-group-specific relationships in the response of species richness to stand age after forest disturbance. Ectomycorrhizal fungi averaged 90 years for recovery to old-growth values (between 45 years and unrecoverable at 95% prediction limits), and epiphytic lichens took 180 years to reach 90% of old-growth values (between 140 years and never for recovery to old-growth values at 95% prediction limits). Non-saproxylic beetle richness, in contrast, decreased as stand age of broadleaved forests increased. The slow recovery by some functional groups essential to ecosystem functioning makes old-growth forest an effectively irreplaceable biodiversity resource that should be exempt from biodiversity offsetting initiatives. © 2015 The Authors Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Multiresource effects of a stand-replacement prescribed fire in the Pinus contorta-Abies lasiocarpa vegetation zone of central Washington.

Treesearch

Arthur R. Tiedemann; Paul M. Woodard

2002-01-01

A stand-replacement prescribed fire in an over-mature lodgepole pine (Pinus contorta Dougl. ex Loud.)-subalpine fir (Abies lasiocarpa (Hook.) Nutt.) stand (snag area) and in a mature lodgepole pine thicket (thicket area) resulted in lower plant diversity within the first year after burning, and as fire energy outputs increased...

Dance Therapy with Physical Therapy for Children with Down Syndrome.

ERIC Educational Resources Information Center

Dupont, Blanche Burt; Schulmann, Diana

This study sought to investigate effects of a dance program on bilateral toe-standing balance and single-point static balance skills of a group of children with Down Syndrome. Thirteen experimental and 10 control group students between the ages of 3 and 13 years were assessed on toe-standing balance and single-point standing balance on the right…

Effects of seasonal prescribved fires on residual overstory trees in oak-dominate shelterwood stands

Treesearch

Patrick H. Brose; David H. Van Lear

1999-01-01

A study was initiated in 1994 to evaluate the degree of bole damage and crown decline residual overstory trees would experience because of prescribed burning of shelterwood stands. Three oak-dominated shelterwood stands, partially harvested 2 to 4 yr earlier, were divided into four treatments (unburned control, spring burn, summer burn, and winter burn). Fifteen...

Vascular plant propagule banks of six eastern hemlock stands and potential response to the hemlock woolly adelgid in the Catskill Mountains of New York

Treesearch

Thad E. Yorks; Donald J. Leopold; Dudley J. Raynal

2000-01-01

We examined propagule banks in six eastern hemlock (Tsuga canadensis (L.) Carriere) stands in the Catskill Mountains of New York. These stands are at risk of mortality due to the hemlock woolly adelgid (Adelges tsugae Annand), but potential effects of mortality on species composition are uncertain.

Effect of seedbed preparation on natural reproduction of spruce and hemlock under dense shade

Treesearch

Grant Davis; Arthur C. Hart

1961-01-01

The cutting practices commonly recommended for spruce-fir stands in the Northeast involve uneven-aged management. The success of this type of management is predicated upon stand structures that have a range of size classes from seedlings to mature trees in intimate mixture. This kind of stand structure requires a continuous supply of reproduction of desirable species....

A Stand-Replacement Prescribed Burn in Sand Pine Scrub

Treesearch

Kenneth W. Outcalt; Cathryn H. Greenberg

1998-01-01

This paper describes fire characteristics and the immediate effects of a prescribed, high-intensity bum on a 12.2 hectare portion of a stand of Ocala sand pine scrub. The fire team on the Seminole District, Ocala National Forest used the BEHAVE fire model to predict the conditions needed to accomplish a stand-replacement bum. Suitable conditions arose on May 11, 1993...

Effect of stand densities on stand dynamics in white fir (Abies concolor) forests in northeast California, USA

Treesearch

Jianwei Zhang; William W. Oliver; Martin W. Ritchie

2007-01-01

Six white fir trials were established during the last half-century to develop guidelines for managing the existing natural stands across northeastern California. We analyzed data collected from these trials at about 5-year intervals since their installation. Because these trials were independent of each other, the design and treatments varied among the sites....

Effect of a Spaced Thinning in Mature Lodgepole Pine on Within-Stand Microclimate and Fine Fuel Moisture Content

Treesearch

R. J. Whitehead; G. L. Russo; B. C. Hawkes; S. W. Taylor; B. N. Brown; H. J. Barclay; R. A. Benton

2006-01-01

Thinning mature forest stands to wide spacing is prescribed to reduce crown bulk density and likelihood of severe crown fire behaviour. However, it may adversely affect surface fuel load, moisture content and within-stand wind, which influence surface fire behaviour and crowning potential. Comparison of a mature lodgepole pine (Pinus contorta Dougl....

Stand development patterns for young planted oak stands on bottomland hardwood restoration sites

Treesearch

Jonathan Stoll; Brent R. Frey

2016-01-01

Over the last several decades, bottomland restoration efforts have established hundreds of thousands of acres of planted hardwood stands throughout the Southeastern U.S. Much of the initial research focused on planting approaches and early growth and survival, contributing to more effective establishment methods. However, less research attention has been focused on...

A Linked Model for Simulating Stand Development and Growth Processes of Loblolly Pine

Treesearch

V. Clark Baldwin; Phillip M. Dougherty; Harold E. Burkhart

1998-01-01

Linking models of different scales (e.g., process, tree-stand-ecosystem) is essential for furthering our understanding of stand, climatic, and edaphic effects on tree growth and forest productivity. Moreover, linking existing models that differ in scale and levels of resolution quickly identifies knowledge gaps in information required to scale from one level to another...

Estimation of crown cover in interior ponderosa pine stands: Effects of thinning and prescribed fire

Treesearch

Nicholas Vaughn; Martin W. Ritchie

2005-01-01

We evaluated the relationship between crown cover measured with a vertical sight tube and stand basal area per acre in treated (thinned, burned, and thinned and burned) and untreated interior ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in northeastern California. Crown cover was significantly related to basal area at the plot level and...

Growth and yield of all-aged Douglas-fir -- western hemlock forest stands: a matrix model with stand diversity effects.

Treesearch

Jingjing Liang; Joseph Buonglorno; Robert A. Monserud

2005-01-01

A density-dependent matrix model was developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) -- western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest stands in the Pacific Northwest of the United States. The model predicted the number and volume of trees for 4 species groups and 19 diameter classes. The parameters...

Effects of even-aged management on forest birds at northern hardwood stand interfaces

Treesearch

Richard M. DeGraaf

1992-01-01

Breeding birds were counted along transects across edges of even-aged northern hardwood stands in the White Mountain National Forest, New Hampshire, U.S.A. Two replicate transects across each of 7 edge types representing 3 classes of contrast (abrupt, intermediate, and subtle) were sampled during June 1983-1985 to define species assemblages at stand edges and estimate...

Epicormic branching of California black oak: effect of stand and tree characteristics

Treesearch

Philip M. McDonald; Martin W. Ritchie

1994-01-01

Young California black oak (Quercus kelloggii Newb.) stands usually require thinning to increase production of acorns and wood products, but epicormic branches, which yield no acorns and constitute a serious lumber degrade. often result. A crown thinning in 60-year-old hardwood stands on a south exposure at the Challenge Experimental Forest in thenorthern Sierra Nevada...

Methanol production from eucalyptus wood chips. Attachment VI. Florida's eucalyptus energy farm: the natural system interface

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

Fishkind, H.H.

1982-05-01

A review of pertinent literature covered the following: eucalypt background, the candidate species, biomass plantation considerations, effects of site production, leachate and allelopathy, and some exotic flora considerations. The comparative eucalypt field survey covers mined land stands, unmined south Florida stands, and Glade County eucalypt stands. The problem of eucalypt naturalization is discussed.

Stem quality of oak in 15-year-old stands: influence of species within harvesting treatment and fencing

Treesearch

Kurt W. Gottschalk

1997-01-01

The effect of harvesting treatment, fencing, and species on the stem quality of oak (Quercus spp.) was evaluated in mixed-hardwood stands on the Allegheny Plateau in central Pennsylvania. The regeneration harvests included commercial clearcut that removed most stems ≥ 15 cm dbh and a clearcut with timber stand improvement (TSI) that removed...

20 years of intensive uneven-aged management: Effect on Growth, Yield, and Species Composition in Two hardwood Stands in West Virginia

Treesearch

George R., Jr. Trimble; George R. Trimble

1970-01-01

In 1948 a study of uneven-aged forest management, with individual tree-selection cuttings, was begun on two 31-acre stands of Appalachian hardwoods in West Virginia. Now, after 20 years, these stands are beginning to show how this kind of management affects growth, yield, and species composition.

Species diversity of polyporoid and corticioid fungi in northern hardwood forests with differing management histories

Treesearch

Daniel L. Lindner; Harold H., Jr. Burdsall; Glen R. Stanosz

2006-01-01

Effects of forest management on fungal diversity were investigated by sampling fruit bodies of polyporoid and corticioid fungi in forest stands that have different management histories. Fruit bodies were sampled in 15 northern hardwood stands in northern Wisconsin and the upper peninsula of Michigan. Sampling was conducted in five old-growth stands, five uneven-age...

Plant distribution and stand characteristics in brackish marshes: Unravelling the roles of abiotic factors and interspecific competition

NASA Astrophysics Data System (ADS)

Carus, Jana; Heuner, Maike; Paul, Maike; Schröder, Boris

2017-09-01

Due to increasing pressure on estuarine marshes from sea level rise and river training, there is a growing need to understand how species-environment relationships influence the zonation and growth of tidal marsh vegetation. In the present study, we investigated the distribution and stand characteristics of the two key brackish marsh species Bolboschoenus maritimus and Phragmites australis in the Elbe estuary together with several abiotic habitat factors. We then tested the effect of these habitat factors on plant growth and zonation with generalised linear models (GLMs). Our study provides detailed information on the importance of single habitat factors and their interactions for controlling the distribution patterns and stand characteristics of two key marsh species. Our results suggest that flow velocity is the main factor influencing species distribution and stand characteristics and together with soil-water salinity even affects the inundation tolerance of the two specie investigated here. Additionally, inundation height and duration as well as interspecific competition helped explain the distribution patterns and stand characteristics. By identifying the drivers of marsh zonation and stand characteristics and quantifying their effects, this study provides useful information for evaluating a future contribution of tidal marsh vegetation to ecosystem-based shore protection.

[Soil quality assessment of forest stand in different plantation esosystems].

PubMed

Huang, Yu; Wang, Silong; Feng, Zongwei; Gao, Hong; Wang, Qingkui; Hu, Yalin; Yan, Shaokui

2004-12-01

After a clear-cutting of the first generation Cunninghamia lanceolata plantation in 1982, three plantation ecosystems, pure Michelia macclurei stand (PMS), pure Chinese-fir stand (PCS) and their mixed stand, were established in spring 1983, and their effects on soil characteristics were evaluated by measuring some soil physical, chemical, microbiological and biochemical parameters. After 20 years' plantation, all test indices showed differences among different forest management models. Both PMS and MCM had a favorable effect on soil fertility maintenance. Soil quality assessment showed that some soil functions, e.g., water availability, nutrient availability, root suitability and soil quality index were all in a moderate level under the mixed and pure PMS stands, whereas in a relatively lower level under successive PCS stand. The results also showed that there existed close correlations between soil total organic C (TOC), cation exchange capacity (CEC), microbial biomass-C (Cmic) and other soil physical, chemical and biological indices. Therefore, TOC, CEC and Cmic could be used as the indicators in assessing soil quality in this study area. In addition, there were also positive correlations between soil microbial biomass-C and TOC, soil microbial biomass-N and total N, and soil microbial biomass-P and total P in the present study.

Immediate Beneficial Effects of Mental Rotation Using Foot Stimuli on Upright Postural Stability in Healthy Participants

PubMed Central

Kawasaki, Tsubasa

2013-01-01

The present study was designed to investigate whether an intervention during which participants were involved in mental rotation (MR) of a foot stimulus would have immediate beneficial effects on postural stability (Experiment 1) and to confirm whether it was the involvement of MR of the foot, rather than simply viewing foot stimuli, that could improve postural stability (Experiment 2). Two different groups of participants (n = 16 in each group) performed MR intervention of foot stimuli in each of the two experiments. Pre- and postmeasurements of postural stability during unipedal and bipedal standing were made using a force plate for the intervention. Consistently, postural sway values for unipedal standing, but not for bipedal standing, were decreased immediately after the MR intervention using the foot stimuli. Such beneficial effects were not observed after the MR intervention using car stimuli (Experiment 1) or when participants observed the same foot stimuli during a simple reaction task (Experiment 2). These findings suggest that the MR intervention using the foot stimuli could contribute to improving postural stability, at least when it was measured immediately after the intervention, under a challenging standing condition (i.e., unipedal standing). PMID:24459588

Effect of information feedback on training standing up following stroke: a pilot feasibility study.

PubMed

Stanton, Rosalyn; Ada, Louise; Dean, Catherine M; Preston, Elisabeth

2016-12-01

The ability to stand up is reduced following stroke. Traditional biofeedback is effective in improving the performance of lower limb activities. The aim of this study was to investigate the feasibility of and potential for information feedback from a simple inexpensive device to improve the ability to stand up from a chair in people following stroke. A single-group study with pre-post measures design was used. Twenty people with hemiplegic stroke in inpatient rehabilitation received 10 sessions over 2 weeks of information feedback about foot placement during training of standing up. Progression involved increasing repetitions, increasing difficulty and fading feedback. Feasibility was determined by adherence, time taken, acceptability and safety. Clinical outcomes were the time taken to stand up, quality and foot position measured using the 5-Times-Sit-To-Stand-Test and carryover into daily activities measured by covert observation. The study was feasible with 97% of sessions completed, taking 19 (SD 6) to 25 (SD 10) minutes. Participants understood (4.6/5), found useful (4.6/5), challenging (4.4/5) and would recommend (4.7/5) the training. The time to stand up 5 times decreased by 24 (95% CI -48 to -1) s, and the quality of standing improved by 1.0/10.0 (95% CI 0.2 to 1.8). Carryover of the correct foot placement occurred to real life, with the beginning foot position correct 2.1/3.0 (95% CI 1.6 to 2.6) and end foot position correct 1.8/3.0 (95% CI 1.2 to 2.4) occasions. The training is feasible and has the potential to improve the ability to stand up.

Effects of wildlife forestry on abundance of breeding birds in bottomland hardwood forests of Louisiana

USGS Publications Warehouse

Norris, Jennifer L.; Chamberlain, Michael J.; Twedt, Daniel J.

2009-01-01

Effects of silvicultural activities on birds are of increasing interest because of documented national declines in breeding bird populations for some species and the potential that these declines are in part due to changes in forest habitat. Silviculturally induced disturbances have been advocated as a means to achieve suitable forest conditions for priority wildlife species in bottomland hardwood forests. We evaluated how silvicultural activities on conservation lands in bottomland hardwood forests of Louisiana, USA, influenced species-specific densities of breeding birds. Our data were from independent studies, which used standardized point-count surveys for breeding birds in 124 bottomland hardwood forest stands on 12 management areas. We used Program DISTANCE 5.0, Release 2.0 (Thomas et al. 2006) to estimate density for 43 species with > 50 detections. For 36 of those species we compared density estimates among harvest regimes (individual selection, group selection, extensive harvest, and no harvest). We observed 10 species with similar densities in those harvest regimes compared with densities in stands not harvested. However, we observed 10 species that were negatively impacted by harvest with greater densities in stands not harvested, 9 species with greater densities in individual selection stands, 4 species with greater densities in group selection stands, and 4 species with greater densities in stands receiving an extensive harvest (e.g., > 40% canopy removal). Differences in intensity of harvest influenced densities of breeding birds. Moreover, community-wide avian conservation values of stands subjected to individual and group selection, and stands not harvested, were similar to each other and greater than that of stands subjected to extensive harvest that removed > 40% canopy cover. These results have implications for managers estimating breeding bird populations, in addition to predicting changes in bird communities as a result of prescribed and future forest management practices.

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 the surgeon. Though further investigations should be conducted, adopting the between-standing position deserves serious consideration as it may be the best short-term ergonomic alternative.

Effect of Temperature on Acoustic Evaluation of Standing trees and logs: Part 1-Laboratory investigation

Treesearch

Shan Gao; Xiping Wang; Lihai Wang; R. Bruce. Allison

2012-01-01

The goals of this study were to investigate the effect of environment temperature on acoustic velocity of standing trees and green logs and to develop workable models for compensating temperature differences as acoustic measurements are performed in different climates and seasons. The objective of Part 1 was to investigate interactive effects of temperature and...

Effect of footwear on standing balance in healthy young adult males.

PubMed

Alghadir, Ahmad H; Zafar, Hamayun; Anwer, Shahnawaz

2018-03-01

The present study aimed to evaluate the effect of footwear on standing balance in healthy young adult males. Thirty healthy male participants aged 20-30 years were tested for standing balance on the Balance Master on three occasions, including wearing a sandal, standard shoe, or no footwear (barefoot). The tests of postural stability include; "Modified Clinical Test of Sensory Interaction on Balance" (mCTSIB), "Unilateral Stance" (US), and the "Limits of Stability" (LOS). The balance scores (mCTSIB, US, and LOS) was analyzed. There was a significant effect between footwear conditions for mCTIB with eye closed on a firm surface (p=0.002). There was a significant effect between footwear conditions for the US with eye open and closed (p⟨0.05). There was a significant effect between footwear conditions for LOS reaction time during forward movement (p=0.02). Similarly, there was a significant effect between footwear conditions for LOS reaction time during left side movement (p=0.01). Wearing sandals compared to bare feet significantly increased postural sway and reduced stability in healthy young adult males. However, wearing a standard shoe compared to bare feet did not significantly affect balance scores in standing.

Effects of a flat prosthetic foot rocker section on balance and mobility.

PubMed

Hansen, Andrew; Nickel, Eric; Medvec, Joseph; Brielmaier, Steven; Pike, Alvin; Weber, Marilyn

2014-01-01

Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced stability for standing balance tasks. An experimental prosthetic foot was altered to provide three different flat region lengths within its effective rocker shape. It was hypothesized that longer flat regions of the effective rocker shape would lead to improved standing balance outcomes and reduced walking performance for unilateral transtibial prosthesis users. However, no significant changes were seen in the balance and mobility outcomes of 12 unilateral transtibial prosthesis users when using the three prosthetic foot conditions. Subjects in the study significantly preferred prosthetic feet with relatively low to moderate flat regions over those with long flat regions. All the subjects without loss of light touch or vibratory sensation selected the prosthetic foot with the shortest flat region. More work is needed to investigate the effects of prosthetic foot properties on balance and mobility of prosthesis users.

Research Assistants Caught in Limbo: Considering Their Role in Quantitative, Longitudinal Research with Vulnerable Populations.

PubMed

Zerger, Suzanne; Pridham, Katherine Francombe; Plenert, Erin; Newberry, Caitlin; Whisler, Adam; Fernando, Indira; Ahmed, Naveed

2015-11-01

Research assistants (RAs) play a variety of roles that are critical in making research happen and in determining its quality and effectiveness. Yet their locus of power in the production of knowledge stands in sharp contrast to their relative powerlessness in the hierarchical research organization. This article explores the experiences of RAs engaged in a randomized controlled longitudinal field trial of a Housing First intervention for individuals experiencing homelessness and mental illness in Toronto. They encountered several unexpected effects of navigating the power ascribed to them by both study participants and community service providers. This study underscores the importance of acknowledging that RAs are the face of the research study in the field, and of better understanding implications associated with that fact, especially when marginalized populations and their providers are involved.

Somato stimulation and acupuncture therapy.

PubMed

Zhao, Jing-Jun; Rong, Pei-Jing; Shi, Li; Ben, Hui; Zhu, Bing

2016-05-01

Acupuncture is an oldest somato stimulus medical technique. As the most representative peripheral nerve stimulation therapy, it has a complete system of theory and application and is applicable to a large population. This paper expounds the bionic origins of acupuncture and analyzes the physiological mechanism by which acupuncture works. For living creatures, functionally sound viscera and effective endurance of pain are essential for survival. This paper discusses the way in which acupuncture increases the pain threshold of living creatures and the underlying mechanism from the perspective of bionics. Acupuncture can also help to adjust visceral functions and works most effectively in facilitating the process of digestion and restraining visceral pain. This paper makes an in-depth overview of peripheral nerve stimulation therapy represented by acupuncture. We look forward to the revival of acupuncture, a long-standing somato stimulus medicine, in the modern medical systems.

Flow regime effects on mature Populus fremontii (Fremont cottonwood) productivity on two contrasting dryland river floodplains

USGS Publications Warehouse

Andersen, Douglas C.

2016-01-01

I compared riparian cottonwood (Populus fremontii) productivity-discharge relationships in a relictual stand along the highly regulated Green River and in a naturally functioning stand along the unregulated Yampa River in semiarid northwest Colorado. I used multiple regression to model flow effects on annual basal area increment (BAI) from 1982 to 2011, after removing any autocorrelation present. Each BAI series was developed from 20 trees whose mean size (67 cm diameter at breast height [DBH]) was equivalent in the two stands. BAI was larger in the Yampa River stand except in 2 y when defoliating leaf beetles were present there. I found no evidence for a Yampa flood-magnitude threshold above which BAI declined. Flow variables explained ∼45% of residual BAI variability, with most explained by current-year maximum 90-d discharge (QM90) in the Yampa River stand and by a measure of the year-to-year change in QM90 in the Green River stand. The latter reflects a management-imposed ceiling on flood magnitude—Flaming Gorge Dam power plant capacity—infrequently exceeded during the study period. BAI in the relictual stand began to trend upward in 1992 when flows started to mimic a natural flow regime. Mature Fremont cottonwoods appear to be ecologically resilient. Their productivity along regulated rivers might be optimized using multiyear environmental flow designs.

Independent effects of adding weight and inertia on balance during quiet standing

PubMed Central

2012-01-01

Background Human balance during quiet standing is influenced by adding mass to the body with a backpack, with symmetrically-applied loads to the trunk, or with obesity. Adding mass to the body increases both the weight and inertia of the body, which theoretically could provide counteracting effects on body dynamics and balance. Understanding the independent effects of adding weight and inertia on balance may provide additional insight into human balance that could lead to novel advancements in balance training and rehabilitation. Therefore, the purpose of this study was to investigate the independent effects of adding weight and inertia on balance during quiet standing. Methods Sixteen normal-weight young adult participants stood as still as possible on a custom-built backboard apparatus under four experimental conditions: baseline, added inertia only, added weight only, and added inertia and weight. Results Adding inertia by itself had no measurable effect on center of pressure movement or backboard movement. Adding weight by itself increased center of pressure movement (indicated greater effort by the postural control system to stand as still as possible) and backboard movement (indicating a poorer ability of the body to stand as still as possible). Adding inertia and weight at the same time increased center of pressure movement but did not increase backboard movement compared to the baseline condition. Conclusions Adding inertia and adding weight had different effects on balance. Adding inertia by itself had no effect on balance. Adding weight by itself had a negative effect on balance. When adding inertia and weight at the same time, the added inertia appeared to lessen (but did not eliminate) the negative effect of adding weight on balance. These results improve our fundamental understanding of how added mass influences human balance. PMID:22507125

Independent effects of adding weight and inertia on balance during quiet standing.

PubMed

Costello, Kerry Elizabeth; Matrangola, Sara Louise; Madigan, Michael Lawrence

2012-04-16

Human balance during quiet standing is influenced by adding mass to the body with a backpack, with symmetrically-applied loads to the trunk, or with obesity. Adding mass to the body increases both the weight and inertia of the body, which theoretically could provide counteracting effects on body dynamics and balance. Understanding the independent effects of adding weight and inertia on balance may provide additional insight into human balance that could lead to novel advancements in balance training and rehabilitation. Therefore, the purpose of this study was to investigate the independent effects of adding weight and inertia on balance during quiet standing. Sixteen normal-weight young adult participants stood as still as possible on a custom-built backboard apparatus under four experimental conditions: baseline, added inertia only, added weight only, and added inertia and weight. Adding inertia by itself had no measurable effect on center of pressure movement or backboard movement. Adding weight by itself increased center of pressure movement (indicated greater effort by the postural control system to stand as still as possible) and backboard movement (indicating a poorer ability of the body to stand as still as possible). Adding inertia and weight at the same time increased center of pressure movement but did not increase backboard movement compared to the baseline condition. Adding inertia and adding weight had different effects on balance. Adding inertia by itself had no effect on balance. Adding weight by itself had a negative effect on balance. When adding inertia and weight at the same time, the added inertia appeared to lessen (but did not eliminate) the negative effect of adding weight on balance. These results improve our fundamental understanding of how added mass influences human balance.

Deposition pattern and throughfall fluxes in secondary cool temperate forest, South Korea

NASA Astrophysics Data System (ADS)

Kumar Gautam, Mukesh; Lee, Kwang-Sik; Song, Byeong-Yeol

2017-07-01

Chemistry and deposition fluxes in the rainfall and throughfall of red pine (Pinus densiflora), black locust (Robinia pseudoacacia), and chestnut (Castanea crenata) monocultures, and mixed red pine-black locust-chestnut stands were examined in a nutrient-limited cool temperate forest of central South Korea. Throughfall was enriched in both basic and acidic constituents relative to rainfall, suggesting that both dry deposition and canopy leaching are important sources of throughfall constituents. Net throughfall fluxes (NTFs) of cations and anions significantly differed among four different stands as well as seasonally. Red pine exhibited highest fluxes (TF and NTF) for Ca2+, black locust for K+, mixed stands for Mg2+, and chestnut for Na+. In contrast, NTF of SO42-, NO3-, and NH4+was highest in the red pine, intermediate in the chestnut and mixed stands, and lowest in the black locust. In general, canopy uptake of H+ and NH4+ for all stands was higher in summer than in winter. Dry deposition appears to play a major role in atmospheric deposition to this cool temperate forest, especially in summer. Dry deposition for both cations and anions displayed high spatial variability, even though stands were adjacent to one another and experienced identical atmospheric deposition loads. Canopy leaching of K+ (95-78% of NTF), Mg2+ (92-23% of NTF), and Ca2+ (91-12% of NTF) was highest for the black locust, lowest for chestnut, and intermediate for the red pine and mixed stands. The present study documented significant changes in throughfall chemistry and NTF among different forest stands, which presumably be related with the differences in the canopy characteristics and differences in their scavenging capacity for dry deposition and canopy exchange. Difference in the canopy retention of H+ and base cation leaching suggests that canopy exchange was mainly driven by weak acid excretion and lesser by H+ exchange reaction. Our results indicate that despite a high base cation deposition, a combination of higher input of acidifying constituents, low soil pH, and total acidic deposition approaching South Korean critical loads make regional forest vulnerable to acidification.

Standing up in multiple sclerosis (SUMS): protocol for a multi-centre randomised controlled trial evaluating the clinical and cost effectiveness of a home-based self-management standing frame programme in people with progressive multiple sclerosis.

PubMed

Freeman, J A; Hendrie, W; Creanor, S; Jarrett, L; Barton, A; Green, C; Marsden, J; Rogers, E; Zajicek, J

2016-05-05

Multiple sclerosis (MS) is an incurable, unpredictable but typically progressive neurological condition. It is the most common cause of neurological disability in young adults. Within 15 years of diagnosis, approximately 50 % of affected people are unable to walk unaided, and over time an estimated 25 % depend on a wheelchair. Typically, people with such limited mobility are excluded from clinical trials. Severely impaired people with MS spend much of their day sitting, often with limited ability to change position. In response, secondary complications can occur including: muscle wasting, pain, reduced skin integrity, spasms, limb stiffness, constipation, and associated psychosocial problems such as depression and lowered self-esteem. Effective self-management strategies, which can be implemented relatively easily and cheaply within people's homes, are needed to improve or maintain mobility and reduce sedentary behaviour. However this is challenging, particularly in the latter stages of disease. Regular supported standing using standing frames is one potential option. SUMS is a pragmatic multi-centre randomised controlled trial evaluating use of Oswestry standing frames with blinded outcome assessment and full economic evaluation. Participants will be randomly allocated (1:1) to either a home-based, self-management standing programme (with advice and support) along with their usual care or to usual care alone. Those in the intervention group will be asked to stand for a minimum of 30 min three times weekly over 20 weeks. Each participant will be followed-up at 20 and 36 weeks post baseline. The primary clinical outcome is motor function, assessed using the Amended Motor Club Assessment. The primary economic endpoint is quality-adjusted life years. The secondary outcomes include measures of explanatory physical impairments, key clinical outcomes, and health-related quality of life. An embedded qualitative component will explore participant's and carer's experiences of the standing programme. This is the first large scale multi-centre trial to assess the clinical and cost effectiveness of a home based standing frame programme for people who are severely impaired by MS. If demonstrated to be effective and cost-effective, we will use this evidence to develop recommendations for a health service delivery model which could be implemented across the United Kingdom. ISRCTN69614598 DATE OF REGISTRATION: 3.2.16 (retrospectively registered).

Landsat-based Analysis of Mountain Forest-tundra Ecotone Response to Climate Trends in Sayan Mountains

NASA Technical Reports Server (NTRS)

Kharuk, Viatcheslav I.; Im, Sergey T.; Ranson, K. Jon

2007-01-01

observations of temperatures Siberia has shown a several degree warming over the past 30 years. It is expected that forest will respond to warming at high latitudes through increased tree growth and northward or upward slope migration. migration. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. Making repeated satellite observations over several decades provides an opportunity to track vegetation response to climate change. Based on Landsat data of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure and an upward tree-line shift in the of the forest-tundra ecotone during the last quarter of the 2oth century,. On-ground observations, supporting these results, also showed regeneration of Siberian pine in the alpine tundra, and the transformation of prostrate Siberian pine and fir into arboreal (upright) forms. During this time period sparse stands transformed into closed stands, with existing closed stands increasing in area at a rate of approx. 1 %/yr, and advancing their upper border at a vertical rate of approx. 1.0 m/yr. In addition, the vertical rate of regeneration propagation is approx. 5 m/yr. It was also found that these changes correlated positively with temperature trends

When Principals Rate Teachers: The Best--and the Worst--Stand out

ERIC Educational Resources Information Center

Jacob, Brian; Lefgen, Lars

2006-01-01

Elementary- and secondary-school teachers in the United States traditionally have been compensated according to salary schedules based solely on experience and education. Concerned that this system makes it difficult to retain talented teachers and provides few incentives for them to work to raise student achievement while in the classroom, many…

Teacher Education and Posthumanism

ERIC Educational Resources Information Center

Howlett, Caitlin

2018-01-01

Education faces a tenuous future, straddling a growing divide between a no-longer-relevant past and an uncertain future, a future that calls into question the future of humanity altogether. In the face of such a future, posthumanism stands as a reminder that the divides we make in education are unstable, that things could and likely will be…

Recovery efficiency of whole-tree harvesting

Treesearch

Bryce J. Stokes; William F. Watson

1988-01-01

The recovery of total tree biomass and most components of a stand is a practical economic and management alternative to tree-length harvesting. First, the increased utilization of woody biomass provides additional revenues from the site. Second, the removal and utilization of the stems and crowns reduces site preparation costs and makes tree planting easier. Third,...

2013 Inaugural Parade

NASA Image and Video Library

2013-01-21

Members of The U.S. Army Band, Herald Trumpets Ensemble, look to make sure their feet are on markers in front of the Preidential viewing stand ahead of the 2013 Inauguration Parade, Monday, Jan. 21, 2013 in Washington. President Barack Obama was sworn-in as the nation's 44th President earlier in the day. Photo Credt: (NASA/Bill Ingalls)

Printing Ancient Terracotta Warriors

ERIC Educational Resources Information Center

Gadecki, Victoria L.

2010-01-01

Standing in awe in Xian, China, at the Terra Cotta warrior archaeological site, the author thought of sharing this experience and excitement with her sixth-grade students. She decided to let her students carve patterns of the ancient soldiers to understand their place in Chinese history. They would make block prints and print multiple soldiers on…

Men behind the Women of Educational Leadership in Afghanistan

ERIC Educational Resources Information Center

Reilly, Elizabeth C.

2015-01-01

On nearly any international index of those nations where women suffer the greatest, Afghanistan remains consistently identified within the top ten year after year. Afghanistan stands at a crossroad as the country makes the transition from reliance on extensive support for security from the international community to its own police forces and…

Geographic Information System (GIS) | Virginia Department of Forestry

Science.gov Websites

relationships, making GIS a valuable tool to explore management and policy alternatives. GIS at the Virginia in combination in various VDOF applications. InFOREST can be used to map your property. Foresters can Property Inventory and Stand Mapping Riparian Buffer Tax Credit Program Management Forest Sustainability

Sexual Health Education: Social and Scientific Perspectives and How School Psychologists Can Be Involved

ERIC Educational Resources Information Center

McClung, Ashley A.; Perfect, Michelle M.

2012-01-01

The National Association of School Psychologists' (NASP) official stand on sexual education is that it should be taught in schools to help young people make healthy decisions regarding sex throughout their lives. Accordingly, school psychologists have a responsibility to use their expertise to facilitate these programs. Without a comprehensive…

Professional Development in Real Time

ERIC Educational Resources Information Center

Bills, Patricia; Kulkarni, Madhura; Hart, Reeda Stamper

2017-01-01

Students in Mrs. Wilson's fourth-grade classroom watch in anticipation as the guest teacher, Ms. Davis, demonstrates binary signaling using a lightbulb that flashes when she holds it in her hands. She challenges them to guess what she is trying to "say" while making the lightbulb flash on and off, explaining that the lightbulb stands for…

Using forest inventory data to assess fisher resting habitat suitability in California.

Treesearch

William J. Zielinski; Richard L. Truex; Jeffrey R. Dunk; Tom Gaman

2006-01-01

The fisher (Martes pennanti) is a forest-dwelling carnivore whose current distribution and association with late-seral forest conditions make it vulnerable to stand-altering human activities or natural disturbances. Fishers select a variety of structures for daily resting bouts. These habitat elements, together with foraging and reproductive (denning) habitat,...

39 CFR 241.3 - Discontinuance of post offices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to preserve them for the record. (ii) As a factor in making his or her decision, the district manager... manager, Customer Service and Sales, considered, and the decision must stand on the record. No information...(b), any decision to close or consolidate a post office must be based on certain criteria. These...

Chladni Patterns on Drumheads: A "Physics of Music" Experiment

ERIC Educational Resources Information Center

Worland, Randy

2011-01-01

In our "Physics of Music" class for non-science majors, we have developed a laboratory exercise in which students experiment with Chladni sand patterns on drumheads. Chladni patterns provide a kinesthetic, visual, and entertaining way to illustrate standing waves on flat surfaces and are very helpful when making the transition from one-dimensional…

Use of expert systems for integrated silvicultural planning

Treesearch

Chris B. LeDoux

1997-01-01

The use of silvicultural treatments in hardwood stands presents opportunities for increasing the growth and yield of quality sawtimber and enhancing the suitability of the site for use by numerous species of wildlife. Planners, loggers, and managers must consider multiple aspects of the ecosystem when making silvicultural decisions. In this paper we demonstrate an...

How Do Students Work through Organic Synthesis Learning Activities?

ERIC Educational Resources Information Center

Flynn, Alison B.

2014-01-01

Organic chemistry has the long-standing reputation as a challenging course, and organic synthesis is an aspect of organic chemistry that requires students to make the most links between concepts and requires the highest order of thinking. One-on-one interviews were conducted with students from a second undergraduate organic chemistry course in…

Deep Knowledge: A Strategy for University Budgetary Cuts

ERIC Educational Resources Information Center

Reynolds, Douglas B.

2016-01-01

During and after the Financial Crisis of 2008, many institutions of higher learning have had revenue and budgetary reductions, forcing them to make severe university budget cuts and university reductions in force. Often the university cuts are preceded by a process of evaluation of academic programs where institutions determine what they stand for…

Biosimilars: what do patients need to consider?

PubMed Central

Skingle, Diana

2015-01-01

A view from the EULAR Standing Committee of People with Arthritis/Rheumatism in Europe (SCPARE) on some of the issues that patients might wish to consider about biosimilars in shared decision-making discussions with their rheumatologist. The paper also points to the need for more information on biosimilars being made available in lay language. PMID:26535149

The Place of Community in Social Work Practice Research: Conceptual and Methodological Developments

ERIC Educational Resources Information Center

Coulton, Claudia

2005-01-01

Community is widely acknowledged as a fundamental aspect of social work practice, and this formulation distinguishes social work from other professions. Because of this long-standing tradition, social work needs to make a greater investment in producing scientific knowledge to enable community change and to incorporate community context into…

Observation, Inference, and Imagination: Elements of Edgar Allan Poe's Philosophy of Science

ERIC Educational Resources Information Center

Gelfert, Axel

2014-01-01

Edgar Allan Poe's standing as a literary figure, who drew on (and sometimes dabbled in) the scientific debates of his time, makes him an intriguing character for any exploration of the historical interrelationship between science, literature and philosophy. His sprawling "prose-poem" "Eureka" (1848), in particular, has…

Assessing potential sustainable wood yield

Treesearch

Robert F. Powers

2001-01-01

Society is making unprecedented demands on world forests to produce and sustain many values. Chief among them is wood supply, and concerns are rising globally about the ability of forests to meet increasing needs. Assessing this is not easy. It requires a basic understanding of the principles governing forest productivity: how wood yield varies with tree and stand...

On the variation of inventory estimates for redwood stands

Treesearch

Daniel Opalach

2017-01-01

There is a tremendous amount of variation in the second growth redwood (Sequoia sempervirens (D. Don) Endl.) forests found along the North Coast of California. In order to make prudent management decisions about these forests, foresters and other resource professionals often conduct timber cruises to collect information on tree species, diameters,...

JPRS Report, Soviet Union, Military Affairs, 70th Anniversary of the Soviet Armed Forces

DTIC Science & Technology

1988-07-27

frankness," emphasized Mikhail Sergeyevich Gor- bachev, "has begun to make headway in world affairs, destroying the stereotypes of anti-Sovietism...present he is successfully studying in a military academy. Officer V. Makeyev has great authority among the mis- sile troops. He has been standing

History of Piedmont Forests: Implications For Current Pine Management

Treesearch

D.H. Van Lear; R.A. Harper; P.R. Kapeluck; W.D. Carroll

2004-01-01

Piedmont forests were maintained for millennia in an open condition by anthropogenic- and lightning-ignited fires. After European settlement, row-crop agriculture caused serious soil erosion, making Piedmont soils less capable of supplying moisture and nutrients during drought periods. Dense stands of pine, both naturally and artificially regenerated over the past 70...

An Approach to Developing the Laboratory Through Senior Design Projects.

ERIC Educational Resources Information Center

Faghri, Amir

1987-01-01

Describes a program in which senior engineering students are given the opportunity to design, make, and test apparatus intended for an upper-level teaching laboratory. Discusses such projects as a vapor compressor test stand with refrigerant mass flow measurement, a double-walled concentric annular heat pipe, and a vacuum filling station. (TW)

Parent and School Relations in Latvia

ERIC Educational Resources Information Center

Bluma, Dainuvite; Ivanova, Ilze

2013-01-01

Families in Latvia know what is best for their children, and they make a major contribution to their education. Consequently, it is important to build close partnerships between school and family. This article reviews extant research that provides insight into the nature of school-parent relations in Latvia as the nation stands at the crossroads…

How to establish, maintain and use timber depletion accounts

Treesearch

William C. Siegel

2001-01-01

Section 1221 of the Internal Revenue Code defines capital expenditures. In general, these are amounts spent to acquire real estate or equipment, or to make improvements that increase the value of real estate or equipment already owned. Forestry examples include land, buildings, standing timber, reforestation costs, and tractors and trucks. Property owners who incur...

Aim, Shoot, Ready! Future Teachers Learn to Do Video

ERIC Educational Resources Information Center

Hernandez-Ramos, Pedro

2007-01-01

This paper describes an intensive 2-hr workshop designed to introduce preservice teachers to digital video in the context of an instructional technology course or as a stand-alone activity. Acknowledging time constraints in most real-life instructional situations, this format takes novices with no or very limited knowledge of video making to the…

Cold Rolled Steel and Knowledge: What Can Higher Education Learn about Productivity?

ERIC Educational Resources Information Center

Thille, Candace; Smith, Joel

2011-01-01

Higher education is simply not making substantial progress in addressing its most significant challenges: educating an increasingly diverse body of students while containing the cost that is putting postsecondary education beyond the reach of a growing percentage of the world's population. Tweaking long-standing strategies to achieve incremental…

Diameter growth of subtropical trees in Puerto Rico

Treesearch

Thomas J. Brandeis

2009-01-01

Puerto Rico’s forests consist of young, secondary stands still recovering from a long history of island-wide deforestation that largely abated in the mid-20th century. Limited knowledge about growth rates of subtropical tree species in these forests makes it difficult to accurately predict forest yield, biomass accumulation, and carbon...

Anomalous dark growth rings in black cherry

Treesearch

Robert P. Long; David W. Trimpey; Michael C. Wiemann; Susan L. Stout

2012-01-01

Anomalous dark growth rings have been observed in black cherry (Prunus serotina) sawlogs from northwestern Pennsylvania making the logs unsuitable for veneer products. Thirty-six cross sections with dark rings, each traceable to one of ten stands, were obtained from a local mill and sections were dated and annual ring widths were measured. One or...

Collective hormonal profiles predict group performance.

PubMed

Akinola, Modupe; Page-Gould, Elizabeth; Mehta, Pranjal H; Lu, Jackson G

2016-08-30

Prior research has shown that an individual's hormonal profile can influence the individual's social standing within a group. We introduce a different construct-a collective hormonal profile-which describes a group's hormonal make-up. We test whether a group's collective hormonal profile is related to its performance. Analysis of 370 individuals randomly assigned to work in 74 groups of three to six individuals revealed that group-level concentrations of testosterone and cortisol interact to predict a group's standing across groups. Groups with a collective hormonal profile characterized by high testosterone and low cortisol exhibited the highest performance. These collective hormonal level results remained reliable when controlling for personality traits and group-level variability in hormones. These findings support the hypothesis that groups with a biological propensity toward status pursuit (high testosterone) coupled with reduced stress-axis activity (low cortisol) engage in profit-maximizing decision-making. The current work extends the dual-hormone hypothesis to the collective level and provides a neurobiological perspective on the factors that determine who rises to the top across, not just within, social hierarchies.

Collective hormonal profiles predict group performance

PubMed Central

Akinola, Modupe; Page-Gould, Elizabeth; Mehta, Pranjal H.; Lu, Jackson G.

2016-01-01

Prior research has shown that an individual’s hormonal profile can influence the individual’s social standing within a group. We introduce a different construct—a collective hormonal profile—which describes a group’s hormonal make-up. We test whether a group’s collective hormonal profile is related to its performance. Analysis of 370 individuals randomly assigned to work in 74 groups of three to six individuals revealed that group-level concentrations of testosterone and cortisol interact to predict a group’s standing across groups. Groups with a collective hormonal profile characterized by high testosterone and low cortisol exhibited the highest performance. These collective hormonal level results remained reliable when controlling for personality traits and group-level variability in hormones. These findings support the hypothesis that groups with a biological propensity toward status pursuit (high testosterone) coupled with reduced stress-axis activity (low cortisol) engage in profit-maximizing decision-making. The current work extends the dual-hormone hypothesis to the collective level and provides a neurobiological perspective on the factors that determine who rises to the top across, not just within, social hierarchies. PMID:27528679

Take a stand on your decisions, or take a sit: posture does not affect risk preferences in an economic task.

PubMed

O'Brien, Megan K; Ahmed, Alaa A

2014-01-01

Physiological and emotional states can affect our decision-making processes, even when these states are seemingly insignificant to the decision at hand. We examined whether posture and postural threat affect decisions in a non-related economic domain. Healthy young adults made a series of choices between economic lotteries in various conditions, including changes in body posture (sitting vs. standing) and changes in elevation (ground level vs. atop a 0.8-meter-high platform). We compared three metrics between conditions to assess changes in risk-sensitivity: frequency of risky choices, and parameter fits of both utility and probability weighting parameters using cumulative prospect theory. We also measured skin conductance level to evaluate physiological response to the postural threat. Our results demonstrate that body posture does not significantly affect decision making. Secondly, despite increased skin conductance level, economic risk-sensitivity was unaffected by increased threat. Our findings indicate that economic choices are fairly robust to the physiological and emotional changes that result from posture or postural threat.

Take a stand on your decisions, or take a sit: posture does not affect risk preferences in an economic task

PubMed Central

O’Brien, Megan K.

2014-01-01

Physiological and emotional states can affect our decision-making processes, even when these states are seemingly insignificant to the decision at hand. We examined whether posture and postural threat affect decisions in a non-related economic domain. Healthy young adults made a series of choices between economic lotteries in various conditions, including changes in body posture (sitting vs. standing) and changes in elevation (ground level vs. atop a 0.8-meter-high platform). We compared three metrics between conditions to assess changes in risk-sensitivity: frequency of risky choices, and parameter fits of both utility and probability weighting parameters using cumulative prospect theory. We also measured skin conductance level to evaluate physiological response to the postural threat. Our results demonstrate that body posture does not significantly affect decision making. Secondly, despite increased skin conductance level, economic risk-sensitivity was unaffected by increased threat. Our findings indicate that economic choices are fairly robust to the physiological and emotional changes that result from posture or postural threat. PMID:25083345

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 processing attentional resources under the dual-task postural control paradigm.

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 processing attentional resources under the dual-task postural control paradigm. PMID:28713252

The Effectiveness of Standing on a Balance Board for Increasing Energy Expenditure.

PubMed

Nelson, Megan C; Casanova, Madeline P; Vella, Chantal A

2018-03-01

To investigate differences in energy expenditure (EE), heart rate (HR), productivity, fatigue, and pain while performing desk work while sitting (SIT), standing (STAND), and standing on a balance board (BOARD). Thirty healthy adults (60% female; age 39.7 ± 11.8 y; BMI 26.7 ± 5.0 kg·m) employed in sedentary-based jobs volunteered for this randomized crossover trial. Participants performed typing work in three different positions: SIT, STAND, and BOARD; each condition lasting 30 min. Oxygen consumption (VO2) was measured via indirect calorimetry and EE was calculated using respiratory quotient and corresponding caloric equivalent values. Productivity was quantified by measuring words typed per min, accuracy, and typing mistakes. Overall feelings of fatigue and pain were self-reported three times during each position using validated 10-cm visual analog scales. Repeated measures ANOVA were used to assess differences in outcome variables across conditions. VO2 was significantly different among all conditions regardless of current standing desk use (SIT 3.35 ± 0.53; STAND 3.77 ± 0.48; BOARD 3.92 ± 0.54 mL·kg·min, p<0.001). EE (kcal·min) also differed (p<0.001) among SIT (1.27 ± 0.22), STAND (1.42 ± 0.26) and BOARD (1.48 ± 0.29). Compared to sitting (67 ± 9 bpm), HR was higher in STAND (76 ± 11 bpm) and BOARD (76 ± 11 bpm, p<0.001). Measures of productivity were not different across conditions (p>0.05). Fatigue progressively increased over each 30 min condition whereas pain in SIT and BOARD increased from min 10 to 20, then leveled off between min 20 to 30. For STAND, pain continued to increase over time. Compared with sitting, a balance board may be effective for increasing EE without interfering with productivity in an occupational setting.

When life imitates art: surrogate decision making at the end of life.

PubMed

Shapiro, Susan P

2007-01-01

The privileging of the substituted judgment standard as the gold standard for surrogate decision making in law and bioethics has constrained the research agenda in end-of-life decision making. The empirical literature is inundated with a plethora of "Newlywed Game" designs, in which potential patients and potential surrogates respond to hypothetical scenarios to see how often they "get it right." The preoccupation with determining the capacity of surrogates to accurately reproduce the judgments of another makes a number of assumptions that blind scholars to the variables central to understanding how surrogates actually make medical decisions on behalf of another. These assumptions include that patient preferences are knowable, surrogates have adequate and accurate information, time stands still, patients get the surrogates they want, patients want and surrogates utilize substituted judgment criteria, and surrogates are disinterested. This article examines these assumptions and considers the challenges of designing research that makes them problematic.

Effect of Pelvic Tilt and Rotation on Cup Orientation in Both Supine and Standing Positions.

PubMed

Yun, Hohyun; Murphy, William S; Ward, Daniel M; Zheng, Guoyan; Hayden, Brett L; Murphy, Stephen B

2018-05-01

The purpose of this study is to analyze the effect of pelvic tilt and rotation on radiographic measurement of cup orientation. A total of 68 patients (79 hips) were included in this study. The patients had a computed tomography study and approximately 3 months of postoperative standing anteroposterior pelvic radiographs in both supine and standing positions. We used 2-dimensional (2D)/3-dimensional (3D) matching to measure pelvic tilt and rotation, and cup orientation. There was a wide range of pelvic tilt between individuals in both supine and standing positions. Supine pelvic tilt was different from standing pelvic tilt (P < .05). There were differences in cup anteversion before and after 2D/3D matching in both supine and standing positions (P < .05). Supine and standing pelvic tilt correlated with differences in cup anteversion before and after 2D/3D matching. When all 79 hips were separated into right and left side, pelvic rotation inversely correlated with the pelvic tilt-adjusted difference in anteversion before and after 2D/3D matching of the right side but directly correlated with that of the left side in both supine and standing positions. This study demonstrated that the measurement of cup anteversion on anteroposterior radiographs is significantly affected by both pelvic tilt and pelvic rotation (depending on the side). Improved understanding of pelvic orientation and improved ability to measure pelvic orientation may eventually allow for desired cup positioning to potentially protect against complications associated with malposition of the cup. Copyright © 2017 Elsevier Inc. All rights reserved.

Classroom Standing Desks and Sedentary Behavior: A Systematic Review.

PubMed

Minges, Karl E; Chao, Ariana M; Irwin, Melinda L; Owen, Neville; Park, Chorong; Whittemore, Robin; Salmon, Jo

2016-02-01

Reducing sedentary behaviors, or time spent sitting, is an important target for health promotion in children. Standing desks in schools may be a feasible, modifiable, and acceptable environmental strategy to this end. To examine the impact of school-based standing desk interventions on sedentary behavior and physical activity, health-related outcomes, and academic and behavioral outcomes in school-aged children. Ovid Embase, Medline, PsycINFO, Web of Science, Global Health, and CINAHL. Full-text peer-reviewed journal publications written in English; samples of school-aged youth (5-18 years of age); study designs including the same participants at baseline and follow-up; and use of a standing desk as a component of the intervention. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight studies satisfied selection criteria and used quasi-experimental (n = 4), randomized controlled trial (n = 3), and pre-post, no control (n = 1) designs. When examined, time spent standing increased in all studies (effect sizes: 0.38-0.71), while sitting time decreased from a range of 59 to 64 minutes (effect sizes: 0.27-0.49). Some studies reported increased physical activity and energy expenditure and improved classroom behavior. One-half of the studies had nonrandomized designs, and most were pilot or feasibility studies. This initial evidence supports integrating standing desks into the classroom environment; this strategy has the potential to reduce sitting time and increase standing time among elementary schoolchildren. Additional research is needed to determine the impact of standing desks on academic performance and precursors of chronic disease risk. Copyright © 2016 by the American Academy of Pediatrics.

Stemwood production patterns in ponderosa pine: effects of stand dynamics and other factors

Treesearch

Michael J. Arbaugh; David L. Peterson

1993-01-01

Growth patterns of vertical stems in nine ponderosa pines from a stand in the southern Sierra Nevada were analyzed for recent changes due to stand dominance position, age, climate, and ozone exposure. Large positive correlations were found between increments in volume growth and basal area at d.b.h. The results indicated that patterns of wood distribution along the...