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1
Smith, Walton R. "The Fallacy of Preferred Species". Southern Journal of Applied Forestry 12, n.º 2 (1 de mayo de 1988): 79–84. http://dx.doi.org/10.1093/sjaf/12.2.79.
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Abstract The popularity and market values of major hardwood lumber products occur in cycles, which makes the selection of preferred species a questionable practice in silvicultural treatments. The differences between the 1935 market values of specific lumber products and the values of the same products in later years, and the cycling of values and volume of specific lumber products from the North Carolina National Forests for a 29-year period (1957-1986) suggest that there should be less dependence on current prices and species popularity in planning future forests, and more consideration for soil protection and other nonmonetary values. South. J. Appl. For. 12(2):79-84.
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Li, Chao, Hugh Barclay, Shongming Huang, Harinder Hans y Sirak Ghebremusse. "Sensitivity of predictions of merchantable tree height, log production, and lumber recovery to tree taper". Forestry Chronicle 89, n.º 06 (diciembre de 2013): 741–52. http://dx.doi.org/10.5558/tfc2013-136.
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Tree taper models characterize the change in diameter from the bottom to the top of a tree, thereby contributing to the estimation of tree volume. This paper examines the sensitivity of predictions of merchantable height defined as the tree height at a given top diameter inside bark (DIB) determined by the utilization standard, log production, and lumber recovery to the eight parameters in Kozak’s (1988) tree taper model. We found that predictions of merchantable height and log production were sensitive to two parameters, whereas predictions of the percentage of lumber recovery were sensitive to one parameter. Because the three measures examined in this study are not very sensitive to tree taper, especially the percentage of lumber recovery that is of most concern to the forest industry, together with the relatively small variations in tree taper parameters across Canada and the limited contribution of tree taper to characterizing the value of lumber recovery at the stand scale, one could infer that it may be possible to develop a single Canadian national softwood tree taper model for predicting forest product variables such as log production and percentage of lumber recovery from forest inventory.
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Lynch, Thomas B., Michael M. Huebschmann, David K. Lewis, Daniel S. Tilley y James M. Guldin. "A Bid Price Equation for National Forest Timber Sales in Western Arkansas and Southeastern Oklahoma". Southern Journal of Applied Forestry 28, n.º 2 (1 de mayo de 2004): 100–108. http://dx.doi.org/10.1093/sjaf/28.2.100.
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Abstract An equation relating bid price to timber sale characteristics was developed using regression techniques on the basis of data from 150 timber sales that occurred between June 1992 and Dec. 1998 in the Ozark and Ouachita National Forests in Arkansas and southeastern Oklahoma. Predicted values of the real winning bid price are based on total sawtimber volume per sale, total pulpwood volume per sale, average sawtimber volume per acre, average sawtimber volume per tree, and the ratio of southern yellow pine #2 dimension lumber producer price index (PPI) to pine sawlog PPI. Sawtimber and pulpwood in these sales are mainly shortleaf pine (Pinus echinata Mill.). The most highly significant variables were total sawtimber volume and the ratio of southern yellow pine #2 dimension lumber PPI to pine sawlog PPI. The equation explains 95% of the variation in the total bid price data. South. J. Appl. For. 28(2):100–108.
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Keenan, F. J., M. M. Lepper, A. T. Quaile y E. N. Aplin. "Behaviour of truss plate and metal web joints in machine-stress-rated lumber trusses". Canadian Journal of Civil Engineering 12, n.º 3 (1 de septiembre de 1985): 700–716. http://dx.doi.org/10.1139/l85-076.
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In project A, 1500 pieces of 38 × 89 mm spruce–pine–fir lumber from three mills, in two machine-stress-rated (MSR) grades, 1650f–1.5E and 2100f–1.8E, were proof-loaded to obtain the mean modulus of elasticity, the fifth percentile modulus of elasticity, and the fifth percentile modulus of rupture. Relative density was measured for each piece, and values of the 33.3 and 52.3 percentiles of the relative density ranges were determined for each species/grade category and related to the minimum values stipulated by the National Lumber Grades Authority (NLGA) Special Product Standard SPS-2-82 for machine-stress-rated lumber. The values of relative density at the 33.3 and 52.3 percentiles that will cause the NLGA mean modulus of elasticity MOE (mean), criterion to be just barely satisfied were estimated.In project B, the lateral resistances of 480 truss plate joints were determined. The variables were two common types of truss plates (thicknesses of 0.91 mm and 1.5 mm) in two grades of MSR lumber (1650f–1.5E and 2100f–1.8E) subdivided into two species groups (pine alone and spruce–fir combined), tested at four orientations of load to grain and load to plate axis. These tests showed that, in most cases, an increase in the design capacity of truss plates in MSR lumber over the values now used for spruce–pine–fir lumber is justified.In project C, 30 commercially designed metal web floor trusses of three span/depth combinations were tested to determine their stiffnesses and strengths. Trusses with 2100f grade lumber in the chords were stiffer than the trusses with 1650f chords. In both grades, larger trusses are relatively less stiff than smaller trusses. With respect to strength, the results indicate that higher design values may be used with higher grades of MSR lumber provided that design is governed by either tooth withdrawal at the joints or by chord strength. An improved analytical model, taking into account four distinct failure modes, is required for the behaviour of floor trusses. Key words: machine-stress-rated lumber, truss plates, trusses, metal webs, strength, density.
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Smith, Ian y Ying Hei Chui. "Construction methods for minimizing vibration levels in floors with lumber joists". Canadian Journal of Civil Engineering 19, n.º 5 (1 de octubre de 1992): 833–41. http://dx.doi.org/10.1139/l92-094.
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The National Building Code of Canada 1990 specifies the allowable spans for lumber floor joists that are expected to lead to satisfactory vibrational behaviour. This paper discusses construction methods that improve the floor behaviour once the flooring and joists appropriate to a particular building occupancy have been selected. Laboratory tests on full-size floors demonstrate that adding between-joists bridging and supporting all four floor edges significantly improves the overall vibrational performance of wood floors. Bridging consisting of solid blocking glued to the underside of the flooring and a mild steel strap nailed to the underside of blocking and joists is more effective than several alternative details. Incorporating pads of damping material between flooring and joists, or at bearings, can have a detrimental effect on floor performance. The use of elastomeric adhesive, in lieu of nailed flooring-to-joist connections, does not significantly enhance the mechanical performance of floors with lumber joists. Key words: lumber, vibration, serviceability, floors, design detailing.
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Cothren, Zackery A. y Zachery A. Cothren. "Arkansas Listings in the National Register of Historic Places: Three States Lumber Company in Burdette". Arkansas Historical Quarterly 63, n.º 3 (2004): 315. http://dx.doi.org/10.2307/40038276.
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Zhou, Xian Yan, Jing Hao Li, Zhong Feng Zhang y Wan Xi Peng. "Study on Bonding Capacity of Different Assemble Patterns of Wood Species in Structural Lumber". Advanced Materials Research 168-170 (diciembre de 2010): 578–81. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.578.
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This thesis aims to select the optimal assemble patterns of wood species for structural lumber for wood-based bridge by analysing the bonding strength of eucalyptus veneers, poplar veneers and bamboo mats. Through variance analysis, the experiment results showed that: the compound mode: bamboo mat was used as the core panel, eucalyptus veneers as the surface panel, and the bonding strength is above the national standard. What draws special attention was that thickness of eucalyptus veneers was above 1.3 mm to crack.
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Ganguly, Indroneil y Ivan L. Eastin. "Trends in the US decking market: A national survey of deck and home builders". Forestry Chronicle 85, n.º 1 (1 de enero de 2009): 82–90. http://dx.doi.org/10.5558/tfc85082-1.
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The deck-building industry is going through a period of rapid growth and dramatic change with respect to the types of materials available to build decks. Naturally durable timber species (i.e., redwood, western redcedar, Alaska yellow-cedar and tropical hardwoods) are facing acute competition from engineered decking products, primarily plastic lumber and composite wood products. The results of a 2004 national survey of 156 deck builders and 212 home builders indicate that wood–plastic composites are quickly gaining popularity among deck-building professionals as they increase their market share. This paper investigates deck-building professionals’ use and perceptions of the different decking materials. The study also reveals the usage patterns of the various decking materials in the primary end-use applications (substructure, deck surface and deck accessories). Finally, a comparative assessment of the different decking materials relative to a common set of material attributes is presented. Key words: decking market, deck-building practices, decking material, residential housing, deck builders, homebuilders
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Chakraborty, Prasanta Kumar, Md Shahadat Hossain, Md Jahidul Islam, Md Shahadat Hossain, Monzur Ahmed, Md Ruhul Amin y Dilir Jamal. "Profile of Patients Attending at the Department of Physical Medicine and Rehabilitation in a Specialized Hospital of Bangladesh". Bangladesh Medical Journal 46, n.º 1 (21 de noviembre de 2017): 15–19. http://dx.doi.org/10.3329/bmj.v46i1.34633.
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Physician’s documentation has become the critical component in rehabilitation of patients. The scope of Physical Medicine and Rehabilitation (PMR) encompasses more than a single organ system. Attention to the whole person is paramount. The aim of the study was to appraise the disease pattern and demographic information of the patients received outpatient rehabilitation services at the department of PMR, National Institution of Neuroscience and Hospital, Dhaka, Bangladesh. This is a retrospective study carried out for the period of two years July 2013 to June 2015. Total number of patients was 29678, among them 57.02% were male and 42.98% were female. Maximum patients (26.15%) were in age group 41-50 years and in housewife (37.76%) in occupation, where majority (56.33%) of them came from Dhaka city. Regarding disease pattern, 56.32% was neurological, 33.46% was musculoskeletal and 7.25% of patients were suffering from rheumatologic problem. Among leading diseases, largest disease group was stroke (20.02%), 10.48% was non-specific low back pain, 9.92% was Bell’s palsy, 5.35% was lumbar spondylosis, 5.13% was carpal tunnel syndrome, 4.11% was prolapsed lumber inter-vertebral disk (PLID), 3.72% was cerebral palsy. Knowledge about the existing disease pattern and health seeking behavior is essential to provide need based health care delivery to any population.Bangladesh Med J. 2017 Jan; 46 (1): 15-19
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Adams, Darius M. y Gregory S. Latta. "Costs and regional impacts of restoration thinning programs on the national forests in eastern Oregon". Canadian Journal of Forest Research 35, n.º 6 (1 de junio de 2005): 1319–30. http://dx.doi.org/10.1139/x05-065.
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An intertemporal spatial equilibrium model of the eastern Oregon softwood log market was employed to estimate the market and economic welfare impacts of restoration thinning programs established on national forests in the region. Programs treated only lands with sawtimber thinning volume and varied by the extent of public subsidies for costs, the types of costs that could be subsidized, and the form of the subsidy payment. Impacts on private harvest timing, numbers of mills, and postprogram log prices in the region were found to vary markedly with the form of the program. Log consumers (lumber mills) consistently realized relatively large surplus gains, while private log producers' surplus showed smaller but consistent losses. For a comparable subsidy budget, programs that subsidized only hazard removal costs, on sites where net unsubsidized sawtimber returns promised to be less that these costs, led to a larger area treated than did programs with more flexible subsidy conditions. Across all programs, net agency receipts from sawtimber sales were estimated to be insufficient to cover the costs of all areas in need of thinning treatment (lands with and without sawtimber thinning volume).
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Kelleher, James. "Canadian Interests in Forest Products Trade". Forestry Chronicle 62, n.º 4 (1 de agosto de 1986): 314–16. http://dx.doi.org/10.5558/tfc62314-4.
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The international market environment for forest products has become more competitive. This has resulted from slower growth in demand and increased capacity of producers in importing countries to meet domestic requirements. Exports have also increased from new producing countries. These problems coupled with the much slower recovery of overseas markets have led to conditions of oversupply. Against this background protectionist pressures have grown, particularly against our softwood lumber exports to the United States. It will therefore be important to secure market access for our forest products and reduce remaining trade barriers to allow competitive adjustment of our forest industries. Marketing initiatives will also be required to realize new market opportunities and facilitate increased exports of further processed products. The National Trade Strategy will be a key vehicle in promoting our trade objectives in the sector.
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R. Dzacka, J. Korang, S. Pentsil,. "A decade and half of Ghana’s trade in African Mahogany: A Review". Journal of Energy and Natural Resource Management 3, n.º 1 (24 de febrero de 2018): 1–7. http://dx.doi.org/10.26796/jenrm.v3i1.51.
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This paper sought to review Ghana’s performance with regard to trade in African mahogany from 2001 to 2015. The studyassessed the volume, types of product exported, extent of product innovation and export destinations of the species and woodproducts in general. From the results, the highest export volume was recorded in 2007 (32,149m3) and the least of 14,082m3in 2001. The timber industry was mainly involved in secondary processing of mahogany as veneer, block board, air and kilndried lumber and plywood. Tertiary processing was comparatively low and products like floorings and furniture parts were rarelyexported. The major markets were in Europe, Africa, America, Asia and the Middle East. Considering the depletion of thisimportant timber species in the national forest estate and its attendant loss of revenue, Ghana should vigorously restock degradedareas and incentivize mills engaged in tertiary processing of timber species.
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Wu, Yi Qiang, Chun Hua Yao, Yan Qing, Jian Xiong Lv y Yun Chu Hu. "Performance Evaluation of Flame-Retardant NSCFR-Treated Laminated Veneer Lumber(LVL) PartⅠ:Thermal, Physical and Mechanical Properties". Advanced Materials Research 168-170 (diciembre de 2010): 2106–10. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2106.
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This study aimed at evaluating the physical, mechanical and thermal properties of a structural laminated veneer lumber(LVL) prepared with self-made fire-retardant NSCFR being applied to the adhesive. Cone calorimeter(CONE), thermogravimetry(TG-DTG) and universal testing machine were utilized to assess the performances. Results showed that: fire-resistant and smoke-suppression characteristics of the fire-retardant treated LVL (FRLVL)were satisfactory. The heat release rate(HRR) of it was smaller than that of the untreated wood and it did not exhibit the typical second pkHRR of wood-based materials. It had a residual mass rate of 33.32% after exposure to fire. Overall production rate of CO and CO2, average specific extinction area and average smoke rate for it were remarkably less than that of unprocessed wood. In addition, FRLVL possesses acceptable physical and mechanical properties. It showed higher density and lower thickness swell after 24h water immersion than the control group and the strength parallel to glue-line parameters in static bending----modulus of rupture(MOR), modulus of elasticity(MOE), shear strength(SS) were 38.698 Mpa ,6.376 GPa and 4.389MPa separately, all of which met the corresponding requirements for structural LVL specified in the China National Standard GB/T 20241-2006.
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Swan, E. P. y R. M. Kellogg. "Chemical properties of black cottonwood and balsam poplar". Canadian Journal of Forest Research 16, n.º 3 (1 de junio de 1986): 497–501. http://dx.doi.org/10.1139/x86-088.
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Taxonomically, black cottonwood and balsam poplar are varieties of the same species. However, black cottonwood is excluded from the "northern aspen" species group embraced by the National Lumber Grading Agency grading rules for dimension lumber and from the use as core material in softwood plywood. This study examines the chemical properties of these two species varieties to assess whether continuing differentiation in their utilization is justified. Black cottonwood was sampled at three sites in British Columbia (Fraser Valley, Squamish Valley, Kingcome Inlet) and balsam poplar was sampled at three sites in Alberta (Lodgepole, Slave Lake, Lac La Biche). Representative subsamples of wood and bark meal were prepared from each original sample. Black cottonwood and balsam poplar did not differ significantly in lignin content. Within each species, the heartwood had higher lignin contents than the sapwood. The mean extractive content of the female trees is higher than that of the male trees, but this was statistically significant for only the benzene–alcohol extractive content of the black cottonwood sapwood. The pH and acidity did not differ significantly between species. However, there was a large difference between heart-wood and sapwood pH values in both species; sufficient to provide a basis for their differentiation. Acidity values were higher for both sapwoods than for heartwoods. The chemical component contents of black cottonwood and balsam poplar bark were the same, except for the benzene–alcohol extractive content, which was twice as great in balsam poplar. However, the same chemical components were found in each extractive mixture. Results do not provide any basis for separate commercial utilization of these two varieties of the same species.
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Campos Barker, Alberto. "Módulo de elasticidad dinámico y esfuerzo de compresión paralela a la fibra en ciertas coníferas canadienses". Ciencia & Investigación Forestal 4, n.º 2 (5 de julio de 1990): 145–58. http://dx.doi.org/10.52904/0718-4646.1990.136.
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En el estudio se emplearon cien piezas de madera de 2'' x 4'' perteneciente al grupo de especies madereras canadienses: Spruce-Pine-Fir, de 2,44 m de longitud, en estado verde y adquiridas en los aserraderos ubicados al sur de New Brunswick, Canada. La madera fue separada en dos grupos con contenidos de humedad diferentes y cada uno de estos grupos en dos grados de calidad de aquellos definidos en las Normas de clasificación: National Lumber Grades Authority. El estudio permitió establecer que las mediciones del Módulo de elasticidad obtenidas con el método de vibraciones transversales y longitudinales está altamente correlacionado con el determinado en las probetas normalizadas. Los valores del coeficiente de correlación, r, resultaron de 0,937 y 0,927 para cada uno de los grados en estado seco. Sin embargo, el valor de r fue sólo 0,780 y 0,475 para el estado verde.
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Kellogg, R. M. y E. P. Swan. "Physical properties of black cottonwood and balsam poplar". Canadian Journal of Forest Research 16, n.º 3 (1 de junio de 1986): 491–96. http://dx.doi.org/10.1139/x86-087.
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The objective of this study was to characterize selected properties of black cottonwood and balsam poplar to determine whether these species should be distinguished in their utilization. At present, black cottonwood is excluded from the "northern aspen" species group embraced by the National Lumber Grading Agency grading rules for dimension lumber and from use as core material in softwood plywood. Samples of black cottonwood were obtained from three sites in British Columbia. Samples of balsam poplar were obtained from three sites in Alberta. Ten tres were randomly selected from each site and a single 130 cm long bolt was collected immediately above breast height (1.36 m) from each tree. From two trees on each site, three additional bolts of the same length were collected immediately above the height positions located at 25, 50, and 75% of total tree height. The average basic specific gravity of the two species did not differ significantly (black cottonwood, 0.338; balsam poplar, 0.337) in this study. However, differences do exist between site averages, at least for black cottonwood. The initial green moisture contents differ significantly (black cottonwood, 160.5%; balsam poplar, 120.6%) and may be expected to affect their drying requirements differentially. For both species, the specific gravity increases and the green moisture content decreases with increasing height position in the tree. The average fiber length of black cottonwood is significantly longer than that of balsam poplar. The bending properties of strength and stiffness for black cottonwood were found to be significantly greater than for balsam poplar. Variation of these properties with height position in the tree was studied. Fiber length was found to decrease with increasing height position, while the bending strength properties were not affected by height position.
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Zhao, Xin Jun y Sheng Yong Luo. "Research on System of Quality Assessing and Defects' Information Managing of Strip Steel Surface". Advanced Materials Research 44-46 (junio de 2008): 173–80. http://dx.doi.org/10.4028/www.scientific.net/amr.44-46.173.
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Under the demand of steel enterprise’s production and consumer’s usage, by way of making up and improving continuous function of steel strip surface defects inspection system on-line, the system of grade assessing of surface quality and defects’ information of strip steel has been set up based on quality statistical method. The system of steel strip surface quality grade assessing standards has been analyzed by many steel enterprises in different countries and gotten the limitations of some of the standards. According to the rules of the National Hardwood Lumber Association of America and the feature of Chinese steel enterprise production, the grade assessing standards of steel strip surface quality has been established. Based on character of steel strip surface defects’ information, through the analysis of the requirement, aim and function, system of grade assessing of surface quality and defects’ information managed of strip steel has been developed to fit the demand of the enterprises and consumers.
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Adewopo, Julius B. y Alexandra Felix Locher. "Network-Based Resource-Proximity Analysis of Primary Wood Processing Mills in Arkansas". Southern Journal of Applied Forestry 35, n.º 3 (1 de agosto de 2011): 109–14. http://dx.doi.org/10.1093/sjaf/35.3.109.
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Abstract Primary wood processing mills in Arkansas play a vital role in both the state and the national economy, as evidenced by Arkansas' high national ranking in lumber productivity. Log acquisition from forestlands is invariably constrained by suitability of terrain and road networks; hence, an accurate assessment of the sufficiency of timberlands in servicing mills based on the existing road network and cost-effective log-truck travel time is essential for planning for the future. Many different analyses were carried out on an ArcInfo 9.3.1 workstation to delineate cost-effective sawmill service areas (SSA), timber supply areas (TSA), agricultural lands, and the overlaps that exist between these land patches. Zonal area summation of the land patches was analyzed with a two-sample paired t-test. Results indicated that there were significant pairwise differences (P < 0.0001) in the extent of SSA and TSA, SSA and SSA within TSA, SSA without agricultural lands and SSA within TSA, agricultural lands with SSA, and agricultural lands without SSA. This study indicated that a significant portion (10%) of agricultural lands must be used for optimal stocking of the delineated cost-effective SSA. Furthermore, this study revealed the suitable areas in Arkansas where there are clusters of residual timberlands that can serve as a raw material supply base for new mills.
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Li, Chang Qi, Fan Xiang y Yang Ping. "Integration Utilize Research of Building Waste in Energy Saving of Buildings". Advanced Materials Research 168-170 (diciembre de 2010): 2165–70. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2165.
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The construction reject is in the building construction, the service, the demolition process produces, mainly is the solid reject, including the waste cement block, the asphalt cement block, in the construction process scatters the waste material, each kind of packing material and other rejects which the mortar and the concrete, the broken brick dregs, the metal, the bamboo lumber, the decoration repair produces and so on. In view of the fact that the construction trash composition characteristic and it produces in the construction project scene actual situation, its recycling took the building material, is constructs the waste disposal use the effective method. This article has carried on the comprehensive investigation and the summary to the domestic and foreign construction trash government present situation and the comprehensive utilization technology, has analyzed the construction reject ingredient and the characteristic, has conducted the system analysis research to our country construction reject comprehensive utilization and the construction energy conservation question, and proposed suits our country national condition the construction reject circulation in the construction energy conservation comprehensive utilization.
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Krigstin, Sally, Kaho Hayashi, Jacek Tchórzewski y Suzanne Wetzel. "Current inventory and modelling of sawmill residues in Eastern Canada". Forestry Chronicle 88, n.º 05 (octubre de 2012): 626–35. http://dx.doi.org/10.5558/tfc2012-116.
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Integration within the forest industry in Canada historically developed to optimize use of the available timber resource. Sawmill residues, which were at one time considered waste, changed into a sought-after resource for panel and pulp manufactures. With the downturn in the Canadian forest industry and the 46.5% decrease in nationwide sawn lumber production between 2004 and 2009, the potential for utilizing sawmill residues to develop novel markets presents itself with added encouragement from national and global pressures towards creating a sustainable bio-based economy. Scarcity of information related to quantity and quality of local sawmill residue feedstocks leads to a lack of reliable data that can be used by entrepreneurs to develop sustainable supply chains for this resource. The development of an easily updateable sawmill database for all provinces, Manitoba eastwards, is explained in detail along with the comprehensive presentation of a sawmill residue output calculation model for sawdust, bark, chips/slabs, and shavings. These tools will help to predict current and future sawmill residue availability and aid in the most efficient uses of this resource in the bioeconomy.
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Heckman, Joseph R. "The Role of Trees and Pastures in Organic Agriculture". Sustainable Agriculture Research 4, n.º 3 (18 de junio de 2015): 51. http://dx.doi.org/10.5539/sar.v4n3p51.
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<p>Environmental concerns associated with annual row crop grain production – including soil erosion, soil carbon loss, intensive use of chemicals and petroleum, limited arable land, among others – could be addressed by converting conventional livestock production to an organic pasture based system. The inclusion of tree crops would further enhance the opportunity for feeding pasture- raised livestock by providing shelter and alternative feed sources. Biodiversity is an essential aspect of an organic farm plan. The idea of including tree crops and other perennials into the vision of an organic farm as a “living system” is very much compatible with the goals and philosophy of organic farming. Before modern no-till farming systems were developed, tree crops and pasture systems were found to provide similar benefits for controlling soil erosion and conserving soil carbon. For example, J. Russell Smith’s <em>Tree Crops: A Permanent Agriculture</em> (Smith, 1950) and pioneered tree crop agriculture as the alternative to annual row crops for protecting soils from erosion while producing livestock feed such as acorns, nuts, and fodder. A survey of Mid-Atlantic USA soils under pasture found 60% higher soil organic matter content than cultivated fields. Because United States Department of Agriculture’s National Organic Program (USDA-NOP) standards require dairy cattle consume pasture forage and limited grain (7 C.F.R. pt. 206), organic milk contains higher concentrations of omega-3 and fewer omega-6 fatty acids than conventional milk. Organic standards also state “the producer must not use lumber treated with arsenate or other prohibited materials for new [fence posts] installations or replacement purposes in contact with soil or livestock.” Black locust (<em>Robinia pseudoacacia</em>) is a fast growing renewable alternative to treated lumber with many attributes compatible with organic farming. This versatile tree fixes nitrogen (N), provides flowers for honey bees and other pollinators, and produces a highly durable dense wood ideal for fence posts useable for up to 50 year.</p>
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Harris, Richard. "The Birth of the North American Home Improvement Store, 1905–1929". Enterprise & Society 10, n.º 4 (diciembre de 2009): 687–728. http://dx.doi.org/10.1017/s1467222700008326.
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The idea, and to a lesser extent the reality, of themodern home improvement store was born in the first quarter of the twentieth century. After 1905 the manufacturers of mail-order kit houses soon grew to threaten the local monopoly of retail building suppliers. Themost important of these suppliers were the lumber merchants who provided most of the materials and credit used by building contractors. At first dealers responded by mounting boycotts and by supporting trade-at-home campaigns, but these were successfully challenged in court. A survey of trade journals shows that after 1914 dealers began to act more constructively. Encouraged by the trade press, and helped by state and national associations, by the 1920s they were advertising more effectively and offering a widening range of goods and services to consumers, including house plans. Because many new customers were women, dealers had to hire more courteous staff, clean up their yards, mount better displays, build showrooms and, in time, relocate to more salubrious and heavily-trafficked parts of town. The emergence of the home improvement store is a significant chapter in the history of urban housing, and especially the marketing of housing services, in the twentieth century.
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Luppold, William, John Baumgras y George Barrett. "Utilization of the Eastern Hardwood Resource by the Hardwood Sawmilling Industry". Northern Journal of Applied Forestry 18, n.º 2 (1 de junio de 2001): 37–41. http://dx.doi.org/10.1093/njaf/18.2.37.
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Abstract The eastern hardwood resource contains numerous species that differ in grain, color, texture, and workability. Because the value of hardwoods is derived from appearance, these variations in physical attributes can cause the price for identical grades of hardwood lumber to vary by as much as 600% between species. As a result, there is incentive for primary processors to harvest certain species more intensively than others, which could affect long-term forest composition. This article introduces the concept of relative utilization to augment the infrequently published annualized growth-to-drain ratio and examines the relative utilization of 13 eastern hardwood species on a national and regional basis. An analysis of relative utilization coefficients developed from primary and secondary data showed that black cherry, red oak, hard maple, and yellow-poplar were relatively overutilized, while the gums, hickory, and beech were underutilized. Relative utilization has varied by species over time due to changes in furniture styling and the ability of industry to substitute species. Shade-tolerant species such as hard and soft maple are regenerating faster than shade- intolerant species, resulting in increased long-term supply even if current sawtimber volumes are relatively overutilized. North. J. Appl. For. 18(2):37–41.
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Connolly, Thomas, Cristiano Loss, Asif Iqbal y Thomas Tannert. "Feasibility Study of Mass-Timber Cores for the UBC Tall Wood Building". Buildings 8, n.º 8 (1 de agosto de 2018): 98. http://dx.doi.org/10.3390/buildings8080098.
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The UBC Brock Commons building in Vancouver, which comprises of 18 stories and stands 53 m in height, was at the time of completion in 2016 the world’s tallest hybrid wood-based building. The building’s 17 stories of mass-timber superstructure, carrying all gravity loads, rest on a concrete podium with two concrete cores that act as both the wind and seismic lateral load-resisting systems. Whereas the construction of the concrete cores took fourteen weeks in time, the mass-timber superstructure took only ten weeks from initiation to completion. A substantial reduction in the project timeline could have been achieved if mass-timber had been used for the cores, leading to a further reduction of the building’s environmental footprint and potential cost savings. The objective of this research was to evaluate the possibility of designing the UBC Brock Commons building using mass-timber cores. The results from a validated numerical structural model indicate that applying a series of structural adjustments, that is, configuration and thickness of cores, solutions with mass-timber cores can meet the seismic and wind performance criteria as per the current National Building Code of Canada. Specifically, the findings suggest the adoption of laminated-veneer lumber cores with supplementary ‘C-shaped’ walls to reduce torsion and optimize section’s mechanical properties. Furthermore, a life cycle analysis showed the environmental benefit of these all-wood solutions.
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Bacher, John. "W. C. Clark and the Politics of Canadian Housing Policy, 1935-1952". Articles 17, n.º 1 (7 de agosto de 2013): 4–15. http://dx.doi.org/10.7202/1017697ar.
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To a remarkable extent the course of Canadian housing policy from 1935 to 1952 was set by the deputy minister of finance, W. C. Clark. By developing programs that stimulated the building of new homes for sale, he was able to deflect growing calls for a substantial federal program of subsidized low rental housing. Working in close consultation with representatives of mortgage-lending institutions, including D'Arcy Leonard, and with David Mansur, inspector of mortgages for Sun Life and later president of Central Mortgage and Housing Corporation, Clark was able to build an alliance of realty interests, home builders, life insurance companies, and material supply companies, such as retail lumber dealers. This alliance prevailed over public-housing supporters: trade unions, large construction companies, architects, social workers and urban planners. Clark was largely responsible for drafting the Dominion Housing Act of 1935 and the national housing acts of 1938 and 1944. Although all his legislation was geared to building new homes, and reducing political criticism, these acts also contained misleading and unworkable provisions for low-income housing. During World War II Clark reluctantly accepted rent-control and federal rental housing, but he restricted their scope and oversaw their phasing out by his long-time associate Mansur. Clark was also crucial in developing government programs that fostered large residential builders to plan future urban communities.
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Wang, Peixuan, Shengcai Li, Nicola Macchioni, Sabrina Palanti y Gabriele Milani. "Comprehensive Evaluation Method of Historical Timber Structural Building Taking Fujiu Zhou House as an Example". Forests 12, n.º 9 (30 de agosto de 2021): 1172. http://dx.doi.org/10.3390/f12091172.
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Physical and mechanical properties of timber components are the basis of developing the technical measures for the conservation and restoration of historical timber structural buildings. By means of integrating on-site investigation (such as a visual survey, moisture content test, micro-drilling resistance test, and material samples collection of historical timber components) and laboratory tests, this study proposed a series of methodologies for comprehensively evaluating the physical and mechanical properties of timber. This method can be quickly mastered by various non-professionals and can help the cross-learning of various disciplines engaged in the research of architectural heritage protection. As a trial, the methodologies were applied to survey and assess a typical historical Chinese timber structural building named the Fujiu Zhou house (the house is located in No. 19, Qinglian lane, Yangzhou city, Jiangsu province, China). The paper studies the 224 components of the main structure of the building, including 128 columns and 96 beams. With the help of the components’ defects and damage status, GB/T13942.2-1992 and the National Lumber Grades Authority (NLGA), the grade of timber components was distinguished. The modulus of elasticity (MOE), modulus of rupture (MOR), and other related material properties parameters of timber components were also obtained. The trial results verify that the proposed methodologies are reasonable, and they can be helpful for the conservation of a historical timber structural building.
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Bye, Thomas K., Kathryn R. Carter, David R. Carrier y Steven J. Elmer. "An outside-the-box activity to demonstrate how humans and animals turn". Advances in Physiology Education 43, n.º 3 (1 de septiembre de 2019): 282–87. http://dx.doi.org/10.1152/advan.00159.2018.
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Developing hands-on activities that engage and excite K–12 students is critical for stimulating interest in science-based careers. We created an activity for high school students that required them to integrate biology and physics concepts to experience how humans and animals maneuver through their environments (i.e., turning). Understanding how turning works is important because it accounts for up to 50% of daily walking steps and is needed for survival when animals elude predators and capture prey. For this activity, student groups used 2 × 4 lumber, wood screws, and a power drill to build an apparatus that, when connected to the body, altered rotational inertia (object’s resistance to change in angular motion, I = mass × radius2). Students navigated through a slalom course with the apparatus (increased radius and rotational inertia) and without the apparatus (mass-matched control). Times to complete the course were compared between trials to determine the influence of rotational inertia on turning performance. Students compiled their data, graphed their results, and found that increased rotational inertia decreased turning performance. Results were connected to sports, rehabilitation, and dinosaur evolution. This activity was implemented during local, regional, national, and international outreach events and adapted for use in undergraduate courses as well (total impact, 250 students). At the end of the activity, students were able to 1) describe whether their results supported their hypothesis; 2) explain how radius influences rotational inertia and turning performance; and 3) apply results to real-world examples. Students and teachers appreciated this “outside-the-box” activity with an engineering twist and found it entertaining.
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Alencar, Juliana Bello Mussi y Jorge Daniel de Melo Moura. "Mechanical Behavior of Cross-Laminated Timber Panels Made of Low-Added-Value Timber". Forest Products Journal 69, n.º 3 (1 de enero de 2019): 177–84. http://dx.doi.org/10.13073/fpj-d-18-00037.
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Abstract The cross-laminated timber (CLT) construction system has recently emerged as an excellent alternative for civil construction. The objective of this work is to analyze the structural performance of CLT panels using plantation lumber, especially eucalyptus (Eucalyptus grandis) heartwood and pine (Pinus taeda). After visual grading, all boards were mechanically graded through the ultrasonic nondestructive testing method. Boards were organized to compose four types of three-layered CLT panels: 1) exclusively eucalyptus heartwood (EEE), 2) eucalyptus in the outer layers and pine in the central layer (EPE), 3) exclusively pine (PPP), and 4) pine in the outer layers and eucalyptus in the central layer (PEP). Three panels with graded timber were manufactured for each type, and one more panel was made out of ungraded timber, so each group had four panels altogether. Panels containing eucalyptus in the outer layers (EEE and EPE) were stiffer than the ones with pine in outer layers (PPP and PEP). However, the first two groups presented lower bending strength than the second ones. Modulus of elasticity and modulus of rupture results were compared to values observed in the literature and to the international standard that regulates CLT (American National Standards Institute/American Plywood Association PRG 320). From the four types studied, only panels containing mostly eucalyptus (EEE and EPE) could meet the PRG 320 E2 class. Panels containing mostly pine (PPP and PEP) did not reach the thresholds of any class in terms of stiffness although their resistance was much higher than that specified in the standard.
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Stromqvist, Bjorn, Bo Jonsson, Peter Fritzell, Olle Hagg, Bengt-Erik Larsson y Bengt Lind. "A national register for lumbar spine surgery". Spine Journal 2, n.º 5 (septiembre de 2002): 114. http://dx.doi.org/10.1016/s1529-9430(02)00245-0.
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Werbaneth, Katherine, Praveen Tummalapalli y Carl A. Gold. "National Variability in Prion Disease–Related Safety Policies for Neurologic Procedures". Neurohospitalist 9, n.º 4 (24 de abril de 2019): 222–25. http://dx.doi.org/10.1177/1941874419846338.
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Prion diseases are fatal neurodegenerative disorders that can be transmitted via contact with infective tissue. Variability in hospital safety policies related to prion disease may place health-care workers at risk. We sought to assess variability of safety policies related to prion disease for neurosurgical procedures and lumbar punctures among neurological institutions in the United States. We e-mailed neurologists associated with 2016 US News and World Report “Top 50” Neurology & Neurosurgery Institutions to request hospital policies regarding safety precautions related to prion disease. For institutional surgical policies, the main outcome was concordance with each of the 8 specific precautions described in World Health Organization (WHO) guidelines published in 1999. No similar guidelines are available for lumbar puncture, so themes were identified and quantified among the lumbar puncture policies we collected. Of the 51 institutions contacted, there were 38 responses. Two institutions did not have relevant policies and 3 institutions declined to share their policies, yielding 33 institutional policies for review. Of these, 85% had a surgical policy and 54% had a lumbar puncture policy. Concordance with all 8 specific precautions described in the WHO guidelines was found in 14% of surgical policies. Lumbar puncture policies demonstrated variability in methods of waste disposal and decontamination procedures. There is significant variability in policies regarding safety precautions in patients with suspected prion disease. We advocate for the formation of national or international committees to examine this issue, set new guidelines, and foster implementation at the level of individual institutions.
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Iskandar, M. I. y Achmad Supriadi. "PEMANFAATAN BUNGKIL BIJI KARET SEBAGAI EKSTENDER PEREKAT PADA KAYU LAPIS PULAI (Alstonia angustiloba Miq.)". Jurnal Sains Natural 4, n.º 1 (1 de diciembre de 2017): 85. http://dx.doi.org/10.31938/jsn.v4i1.79.
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Bungkil Use as Seed Rubber Extender Gluten in Plywood Pulai (Alstonia angustiloba miq.) Indonesia has the largest area of rubber trees in the world, in 2012 reached 3.5 million ha. As a producer of latex, rubber plant also produces lumber and rubber seeds. Rubber seeds have a starch content of 15.9%, so have the opportunity to be made extenders as mixing the adhesive material. This study aimed to determine the utilization of rubber seed meal as an extender adhesives Urea Formaldehyde (UF) on plywood pulai. Extender material made with varying levels of 10%, 20% and 30% respectively of the weight of the liquid adhesive. Variations intended use extenders levels in order to know the quality of plywood produced from a wide variety of levels of these extenders. The results showed that the average moisture content of plywood island 7.97%, density of 0.485 g / cm3, and the bonding strength of 11.36 kg / cm2. The water content and the bonding strength of plywood pulai ware designed to meet the Indonesian National Standard. Statistically analysis levels extenders very significant effect on the bonding strength of plywood pulai. The higher levels of extenders, bonding strength of plywood pulai tends to decrease. Plywood pulai that has the best bonding strength value was the use of extender content of 10%.Keywords: extenders, adhesives, rubber seed meal, plywood, quality pulaiABSTRAK Indonesia memiliki areal tanaman karet terluas di dunia, pada tahun 2012 mencapai 3,5 juta ha. Sebagai penghasil getah, tanaman karet juga menghasilkan kayu dan biji karet. Biji karet memiliki kandungan pati 15,9 %, sehingga berpeluang untuk dibuat ekstender sebagai bahan pencampur perekat. Penelitian ini bertujuan untuk mengetahui pemanfaatan bungkil biji karet sebagai ekstender perekat Urea Formaldehida (UF) pada kayu lapis pulai. Bahan ekstender dibuat dengan kadar bervariasi yaitu 10 %, 20 % dan 30 % masing-masing dari bobot perekat cair. Variasi penggunaan kadar ekstender bertujuan agar dapat diketahui mutu kayu lapis yang dihasilkan dari berbagai variasi kadar ekstender tersebut. Hasil penelitian menunjukkan bahwa rata-rata kadar air kayu lapis pulai 7,97 %, kerapatan 0,485 gr/cm3, dan keteguhan rekat 11,36 kg/cm2. Kadar air dan keteguhan rekat kayu lapis pulai yang dibuat memenuhi Standar Nasional Indonesia. Secara statistik kadar ekstender berpengaruh sangat nyata terhadap keteguhan rekat kayu lapis pulai. Makin tinggi kadar ekstender, keteguhan rekat kayu lapis pulai cenderung berkurang. Kayu lapis pulai yang memiliki nilai keteguhan rekat terbaik adalah yang menggunakan ekstender kadar 10 %.Kata kunci : Ekstender, perekat, bungkil biji karet, kayu lapis, kualitas pulai
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Hassebrock, Jeffrey D., Karan A. Patel, Justin L. Makovicka, Andrew S. Chung, Sailesh V. Tummala, Austin J. Peña, Kyle E. Williams, David E. Hartigan y Anikar Chhabra. "Lumbar Spine Injuries in National Collegiate Athletic Association Athletes: A 5-Season Epidemiological Study". Orthopaedic Journal of Sports Medicine 7, n.º 1 (1 de enero de 2019): 232596711882004. http://dx.doi.org/10.1177/2325967118820046.
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Background: Lumbar spine injuries in National Collegiate Athletic Association (NCAA) athletes have not been well studied. Purpose: To describe the epidemiology of lumbar spine injuries in NCAA athletes during the 2009/2010 through 2013/2014 academic years utilizing the NCAA Injury Surveillance Program (ISP). Study Design: Descriptive epidemiology study. Methods: A voluntary convenience sample of NCAA varsity teams from 25 sports was examined. Mechanism of injury, injury recurrence, and time lost from sport were recorded. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). AEs were defined as any student participation in 1 NCAA-sanctioned practice or competition. Injury rate ratios and injury proportion ratios were calculated to compare the rates within and between sports by event type, season, patient sex, mechanism, injury recurrence, and time lost from sport. Comparisons between sexes were made utilizing data that had both male and female samples. Results: An estimated 50,834 lumbar spine injuries were identified. The overall rate of injuries was 2.88 per 10,000 AEs. The rate of injuries was 2.60 per 10,000 AEs in men compared with 2.89 per 10,000 AEs in women for sex-comparable sports. Women were 1.11 times more likely than men to suffer a lumbar spine injury. Women's gymnastics (8.02 injuries per 10,000 AEs) and women's tennis (5.73 injuries per 10,000 AEs) had the highest rates of lumbar spine injuries. Athletes were 1.6 and 2.4 times more likely to sustain a lumbar spine injury during the preseason than the regular season or postseason, respectively. Noncontact was the most common mechanism of injury (45%). Injury recurrence was most common in men’s outdoor track (43%). Most injuries resulted in less than 24 hours of time loss from event participation (64%). Conclusion: The rate of lumbar spine injuries was high in NCAA athletes, and injuries commonly recurred (20.73%). In general, women were more likely to sustain a lumbar spine injury compared with men. Higher injury rates occurred during competition and via a noncontact mechanism of injury. In addition to prevention programs, reconditioning programs should be considered to prevent these injuries.
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Rozan, Mansoorehossadat, Vahid Rouhollahi, Amit Rastogi y Dilip Kumar Dureha. "Influence of Physiological Loading on the Lumbar Spine of National Level Athletes in Different Sports". Journal of Human Kinetics 50, n.º 1 (1 de abril de 2016): 115–23. http://dx.doi.org/10.1515/hukin-2015-0148.
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AbstractThe lumbar spine is subjected to considerable stress during many athletic efforts. The purpose of this study was to assess the effects of physiological loading on the lumbar spine in national male players of different games, which may be predictive of the future development of low back pain and injury symptoms. Thirty-four national players (12 cricket players, 12 field hockey players, and 10 basketball players) underwent magnetic resonance imaging, and selected geometric variables including intervertebral disc angles, the Farfan ratio, the lumbar body index, the compression deformity ratio, the biconcave deformity ratio and the anterior wedge deformity ratio were measured using KINOVEA-0.8.15 software and syngo fast view software and calculated using specific formulas. The results indicated a significant difference in the intervertebral disc angle between the three groups at the L2/3, L3/4 and L4/5 levels. In relation to the lumbar vertebral body shape and size, significant differences were found in the lumbar index at the L2 level, in the biconcave deformity at the L1 and L2 levels and in relation to the anterior wedge deformity at L2 between the three selected groups. Our data suggest that the different physiological loadings in the selected sports play an important role in the development of degenerative changes of the lumbar spine, which may be considered a risk factor for future injury and/or low back pain in each specific sport because of the unique demands of each discipline.
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Jhawar, Balraj S., Demytra Mitsis y Neil Duggal. "Wrong-sided and wrong-level neurosurgery: a national survey". Journal of Neurosurgery: Spine 7, n.º 5 (noviembre de 2007): 467–72. http://dx.doi.org/10.3171/spi-07/11/467.
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Object Perhaps the single greatest error that a surgeon hopes to avoid is operating at the wrong site. In this report, the authors describe the incidence and possible determinants of incorrect-site surgery (ICSS) among neurosurgeons. Methods The authors asked neurosurgeons to complete an anonymous survey. These surgeons were asked to report the number of craniotomies and lumbar and cervical discectomies performed during the previous year, as well as whether ICSS had occurred. They were also asked detailed questions regarding the potential determinants of ICSS. Results There was a 75% response rate and a 68% survey completion rate. Participating neurosurgeons performed 4695 lumbar and 2649 cervical discectomies, as well as 10,203 craniotomies. Based on this self-reporting, the incidence of wrong-level lumbar surgery was estimated to be 4.5 occurrences per 10,000 operations. The ICSSs per 10,000 cervical discectomies and craniotomies were 6.8 and 2.2, respectively. Neurosurgeons recognized fatigue, unusual time pressure, and emergent operations as factors contributing to ICSS. For spine surgery, in particular, unusual patient anatomy and a failure to verify the operative site by radiography were also commonly reported contributors. Conclusions Neurosurgical ICSSs do occur, but are rare events. Although there are significant limitations to the survey-based methodology, the data suggest that the prevention of such errors will require neurosurgeons to recognize risk factors and increase the use of intraoperative imaging.
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Baaj, Ali A., Katheryne Downes, Alexander R. Vaccaro, Juan S. Uribe y Fernando L. Vale. "Trends in the treatment of lumbar spine fractures in the United States: a socioeconomics perspective". Journal of Neurosurgery: Spine 15, n.º 4 (octubre de 2011): 367–70. http://dx.doi.org/10.3171/2011.5.spine10934.
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Object The objective of this study was to investigate a national health care database and analyze demographics, hospital charges, and treatment trends of patients diagnosed with lumbar spine fractures in the US over a 5-year period. Methods Clinical data were derived from the Nationwide Inpatient Sample (NIS) for the years 2003 through 2007. The NIS is maintained by the Agency for Healthcare Research and Quality and represents a 20% random stratified sample of all discharges from nonfederal hospitals within the US. Patients with lumbar spine fractures were identified using the appropriate ICD-9-CM code. Data on the number of vertebral body augmentation procedures were also retrieved. National estimates of discharges, hospital charges, discharge patterns, and treatment with spinal fusion trends were retrieved and analyzed. Results More than 190,000 records of patients with lumbar spine fractures were abstracted from the database. During the 5-year period, there was a 17% increase in hospitalizations for lumbar spine fractures. This was associated with a 27% increase in hospital charges and a 55% increase in total national charges (both adjusted for inflation). The total health care bill associated with lumbar spine fractures in 2007 exceeded 1 billion US dollars. During this same time period, there was a 24% increase in spinal fusions for lumbar fractures, which was associated with a 15% increase in hospital charges. The ratio of spinal fusions to hospitalizations (surgical rate) during this period, however, was stable with an average of 7.4% over the 5-year period. There were an estimated 13,000 vertebral body augmentation procedures for nonpathological fractures performed in 2007 with a total national bill of 450 million US dollars. Conclusions An increasing trend of hospitalizations, surgical treatment, and charges associated with lumbar spine fractures was observed between 2003 and 2007 on a national level. This trend, however, does not appear to be as steep as that of surgical utilization in degenerative spine disease. Furthermore, the ratio of spinal fusions to hospitalizations for lumbar fractures appears to be stable, possibly indicating no significant changes in indications for surgical intervention over the time period studied.
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Matsuura, Yuiko, Mika Hangai, Keisuke Koizumi, Koji Ueno, Norimasa Hirai, Hiroshi Akuzawa y Koji Kaneoka. "Injury trend analysis in the Japan national swim team from 2002 to 2016: effect of the lumbar injury prevention project". BMJ Open Sport & Exercise Medicine 5, n.º 1 (noviembre de 2019): e000615. http://dx.doi.org/10.1136/bmjsem-2019-000615.
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ObjectivesThis study aimed to clarify the trends of injury occurrence in the Japan national swim team for 15 years and to evaluate the effectiveness of the lumbar injury prevention project. It also aimed to verify the incidence of swimming-related injuries among swimmers by sex, age and swimming style.MethodsThe target group comprised 488 swimmers who participated in the Olympics, Asian Games and Universiade from 2002 to 2016; we compiled data for the total number of injuries in each body part. The lumbar injury prevention project started in 2008 and included two components (deep trunk muscle exercises and evaluation of lumbar disc degeneration using MRI). We analysed the prevalence of lumbar injury before (2002–2008) and after (2009–2016) implementation of the lumbar injury prevention project by χ2 test. We compared age, sex and swim strokes between the injured and non-injured groups by χ2 test and unpaired t-test.ResultsThe most common injury site was the lower back, followed by the shoulder and knee. The lumbar injury prevalence was significantly lower after implementation of the prevention project (23.5% vs 14.8%; p<0.05). Shoulder injuries were common in backstroke swimmers. The injury rate was significantly higher in female than in male swimmers. The injured group was significantly older than the non-injured group.ConclusionsLumbar injury prevention intervention might be effective to prevent lower back injury in swimmers. Injury risk factors included female and old age; younger female athletes should prevent the development of injuries as they mature.
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Syahmitalia, Vida, Zaenal Arifin y Rusmanto Rusmanto. "Analisis Nilai Diagnostic Reference Level (DRL) Dewasa Pemeriksaan Lumbal Spine Anterior-Posterior (AP) dan Lateral (LAT) Modalitas Radiografi Umum di Indonesia Berdasarkan Database Dosis Pasien Si-INTAN". Jurnal Pengawasan Tenaga Nuklir 1, n.º 1 (26 de julio de 2021): 47–51. http://dx.doi.org/10.53862/jupeten.v1i1.010.
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Diagnostic Reference Level (DRL) is a tool for optimizing radiation protection for patients. DRL is also applied to the general radiographic modality of the Anterior-Posterior (AP) and Lateral (LAT) lumbar spine examination. This study aims to determine and analyze provincial and national DRL values that are useful as a reference for general radiographic examination of the Lumbar Spine AP and LAT. Using Si-INTAN secondary data starting with grouping and eliminating ESAK values, determining the national body mass reference, calculating the second quartile value (Q2) for local DRL, and third quartile (Q3) for provincial and national. National DRL on this result was also compared regarding DRL in previous studies. The results of this study indicate the DRL values of several provinces in Indonesia on general radiographic examination of the lumbar spine (AP and LAT), namely Banten 4.31 mGy and 7.88 mGy, DKI Jakarta 6.13 mGy and 5.40 mGy, Jambi 1.88 mGy, West Java 2.54 mGy and 4.18 mGy, Central Java 3.25 mGy and 5.81 mGy, Riau Islands 4.19 mGy and 6.78 mGy, Riau 4.31 mGy and 5.90 mGy, Sulawesi Central 2.15 mGy and 9.57 mGy, North Sumatera 1.04 mGy and 2.90 mGy, and national 4.31 mGy and 7.05 mGy. The difference in DRL values is influenced by exposure parameters, the expertise of related human resources, and the patient’s body mass.
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Bernstein, David N., David Brodell, Yue Li, Paul T. Rubery y Addisu Mesfin. "Impact of the Economic Downturn on Elective Lumbar Spine Surgery in the United States: A National Trend Analysis, 2003 to 2013". Global Spine Journal 7, n.º 3 (6 de abril de 2017): 213–19. http://dx.doi.org/10.1177/2192568217694151.
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Study Design: Retrospective database analysis. Objective: The impact of the 2008-2009 economic downtown on elective lumbar spine surgery is unknown. Our objective was to investigate the effect of the economic downturn on the overall trends of elective lumbar spine surgery in the United States. Methods: The Nationwide Inpatient Sample (NIS) was used in conjunction with US Census and macroeconomic data to determine historical trends. The economic downturn was defined as 2008 to 2009. Codes from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), were used in order to identify appropriate procedures. Confidence intervals were determined using subgroup analysis techniques. Results: From 2003 to 2012, there was a 19.8% and 26.1% decrease in the number of lumbar discectomies and laminectomies, respectively. Over the same time period, there was a 56.4% increase in the number of lumbar spinal fusions. The trend of elective lumbar spine surgeries per 100 000 persons in the US population remained consistent from 2008 to 2009. The number of procedures decreased by 4.5% from 2010 to 2011, 7.6% from 2011 to 2012, and 3.1% from 2012 to 2013. The R2 value between the number of surgeries and the S&P 500 Index was statistically significant ( P ≤ .05). Conclusions: The economic downturn did not affect elective lumbar fusions, which increased in total from 2003 to 2013. The relationship between the S&P 500 Index and surgical trends suggests that during recessions, individuals may utilize other means, such as insurance, to cover procedural costs and reduce out-of-pocket expenditures, accounting for no impact of the economic downturn on surgical trends. These findings can assist multiple stakeholders in better understanding the interconnectedness of macroeconomics, policy, and elective lumbar spine surgery trends.
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Kim, Young-Ki, Dongmug Kang, Ilho Lee y Se-Yeong Kim. "Differences in the Incidence of Symptomatic Cervical and Lumbar Disc Herniation According to Age, Sex and National Health Insurance Eligibility: A Pilot Study on the Disease’s Association with Work". International Journal of Environmental Research and Public Health 15, n.º 10 (25 de septiembre de 2018): 2094. http://dx.doi.org/10.3390/ijerph15102094.
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The aim of this research was to identify the differences in the incidence of symptomatic cervical and lumbar disc herniation according to age, sex, and national health insurance eligibility. We evaluated the hospital documents of patients who received medical treatment for symptomatic cervical and lumbar disc herniation between 2004 and 2010 and excluded those who claimed to have expenses at oriental medical clinics or pharmacies. Furthermore, any duplicate documents from the labor force population aged 20–69 years were excluded from the analysis. The results showed that the number of individuals diagnosed with symptomatic cervical and lumbar disc herniation increased with age, and the incidence of these diseases was higher in women than in men. Additionally, the incidence differed depending on the subject’s qualification for health insurance. The incidence of lumbar disc herniation showed differences depending on the degree of the lumbar burden. The present study findings may help determine whether lumbar disc herniation is associated with tasks performed at the patient’s workplace. Further research is needed to classify the risk of lumbar disk herniation in the workplace into detailed categories such as types of business, types of occupation, and lumbar compression force.
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Akyuva, Yener, Aylin Gonultas, Numan Karaaslan, Zehra Gulciftci Dagci, Semih Saglik, Mehmet Isyar y Mahir Mahirogullari. "Lumbar Spinal Angiolipoma with Expanding Left Neural Foramen Mimicking Lumbar Schwannoma; Case Report and Review of The Literature". Open Neurology Journal 11, n.º 1 (26 de septiembre de 2017): 20–26. http://dx.doi.org/10.2174/1874205x01711010020.
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Aim: To describe a patient with lumbar angiolipoma mimicking schwannoma in the posterolateral side of the spinal canal with expansion of the left lumbar foramen and to discuss the clinical, radiologic, and surgical features of these lesions with literature. Methods: Without language restriction in this paper, the electronic databases; The Cochrane Collaboration the Cochrane, The Cochrane Library (Issue 2 of 12, Feb. 2011), ProQuest, US National Library of Medicine, National Institutes of Health (NLM) and PubMed dating from 1966 September to January Week 2 2017, were searched for comparative experimental studies using the terms: “OR”, “AND”. On-line literature searches were conducted using the key words “lumbar angiolipoma”, “schwannoma “, “spinal angiolipoma”, “spinal cord”, and “spinal canal”. We compared this research with our patient. Results: Bilateral L2 total laminectomy, excision of the tumors and bilateral L2-L3 transpedicular stabilization were performed, and complaints improved prominently. Pathological examination was reported as angiolipoma. Conclusion: The research shows that a probable diagnosis in such tumor cases could be made by sufficient pre-op scanning before surgical operations and although angiolipoma has been rarely seen in lumbar posterolateral space, it can be seen in lumbar region and mimic schwannoma as producing symptoms and signs of spinal cord and nerve root compression.
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Cenic, Aleksa y Edward Kachur. "Lumbar Discectomy: A National Survey of Neurosurgeons and Literature Review". Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 36, n.º 2 (marzo de 2009): 196–200. http://dx.doi.org/10.1017/s0317167100006557.
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Background:To ascertain neurosurgical practices in the surgical management of one-level lumbar discectomies in the Canadian adult population.Methods:One page questionnaire faxed to each Neurosurgeon in Canada with questions relating to their practice in the management of this common neurosurgical procedure. All data analyzed using Chi-square statistics.Results:112 completed surveys were returned hence, giving a 64% response rate with the respondents being predominantly adult neurosurgeons. Of the respondents, 88% perform lumbar discectomy in adults. Only 15% of respondents had a Spine Fellowship. For preoperative imaging, 44% use BOTH CT and MRI whereas 28% use only MRI and 15% use only CT. Prior to initial skin incision, 57% use a localization X-ray image. Preoperative antibiotics are prescribed by 92% of respondents. Majority of respondents (60%) use a pre-incision local anesthetic, whereas only a minority (44%) of respondents employ pre-closure intramuscular injection. With respect to magnification, 70% use microscope, 19% loupes, and 8% neither. Only 12% use minimally invasive tubular retractors. 68% remove “as much disc as possible”, while 31% remove “ONLY herniated part”. In the case of dural tears, 77% of respondents use fibrin glue (Tisseel®). Prior to skin closure, majority of neurosurgeons do NOT use a fat graft (72%), whereas 61% of respondents use epidural steroids. With respect to discharge from the hospital, 58% are discharged on the next day, 18% on the same day, and 23% in two days. Return to work is not recommended until at least six weeks post-op (96%). Most neurosurgeons (93%) would not operate on an individual with a chief complaint of low back pain.Conclusions:Our survey has identified variations in practice patterns amongst Canadian Neurosurgeons with respect to performing one-level lumbar discectomies. This survey is expected to form a basis for the design of a randomized controlled trial in the evaluation of the best management approach for this common neurosurgical procedure.
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Minhas, Shobhit V., Benjamin S. Kester y Wellington K. Hsu. "Outcomes After Lumbar Disc Herniation in the National Basketball Association". Sports Health: A Multidisciplinary Approach 8, n.º 1 (29 de septiembre de 2015): 43–49. http://dx.doi.org/10.1177/1941738115608361.
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Savage, Jason W. y Wellington K. Hsu. "Statistical Performance in National Football League Athletes After Lumbar Discectomy". Clinical Journal of Sport Medicine 20, n.º 5 (septiembre de 2010): 350–54. http://dx.doi.org/10.1097/jsm.0b013e3181efc259.
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Strömqvist, Björn. "Evidence-based lumbar spine surgery: The role of national registration". Acta Orthopaedica Scandinavica 73, sup305 (enero de 2002): 34–39. http://dx.doi.org/10.1080/000164702760379530.
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Wu, Jau-Ching, Yu-Chun Chen, Laura Liu, Wen-Cheng Huang, Peck-Foong Thien, Tzeng-Ji Chen, Henrich Cheng y Su-Shun Lo. "Lumbar spine fusion surgery and stroke: a national cohort study". European Spine Journal 21, n.º 12 (22 de junio de 2012): 2680–87. http://dx.doi.org/10.1007/s00586-012-2405-x.
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Zhang, Xiangyang. "Weightlifter Lumbar Physiology Health Influence Factor Analysis of Sports Medicine". Open Biomedical Engineering Journal 9, n.º 1 (5 de octubre de 2015): 266–70. http://dx.doi.org/10.2174/1874120701509010266.
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Chinese women's weightlifting project has been in the advanced world level, suggesting that the Chinese coaches and athletes have many successful experiences in the weight lifting training. Little weight lifting belongs to high-risk sports, often leading to the lumbar spine injury; some young good athletes, often due to lumbar trauma, had to retire, and the national investment and athletes toil is regret things. This article, based on weightlifting athletes training situation analysis, presents suggestions from the perspective of sports medicine, aimed at avoiding lumbar injury, guaranteeing the health of athletes. In this paper, first of all, 50 professional women's weightlifting athletes were investigated, and it was found that 82% of the athletes suffered from lumbar disease symptoms. The reason was mainly lumbar strain of high intensity and motion error caused by three factors. On the basis of sports medicine and the characteristics of the structure of human body skeleton athletes lumbar structural mechanics analysis, find out the lumbar force's two biggest technical movement, study, and regulate the action standard, so as to minimize lumbar force, for athletes to contribute to the health of the lumbar spine.
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Olivero, William C., Dorla Vinson, Charles Pierce y Sarah Trumbull. "106 Correlation Between Press Ganey Scores and Quality Outcomes from N2QOD (Lumbar Spine) for a Hospital Employed Neurosurgical Practice". Neurosurgery 64, CN_suppl_1 (24 de agosto de 2017): 221. http://dx.doi.org/10.1093/neuros/nyx417.106.
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Abstract INTRODUCTION Press Ganey is a national organization which supplies data to hospitals and clinics regarding patient satisfaction. They contend that patient satisfaction can be used as a surrogate for health care quality and outcomes. N2QOD is a national registry for neurosurgical procedures that tracks a variety of quality indicators and outcomes. METHODS We compared Press Ganey scores for 4 hospital employed neurosurgeons whose primary practice involves spinal surgery to their results from N2QOD for lumbar surgery(over 75% of surgical volume involves the lumbar surgery) RESULTS >We found a negative correlation between Press Ganey scores and the quality outcomes for lumbar surgery. For example those metrics involving patient satisfaction on N2QOD (Met, Not as much as hoped, Would not undergo, Same or worse). The surgeon with the lowest Press Ganey scores had the best outcomes (0 percent would not undergo or were worse) and the surgeon with the highest Press Ganey scores had the worst outcomes (38 percent would not undergo or were worse). CONCLUSION We found a negative correlation between Press Ganey scores and quality outcomes for lumbar surgery as measured by N2QOD.
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Martini, Michael L., Dominic A. Nistal, Brian C. Deutsch y John M. Caridi. "Characterizing the risk and outcome profiles of lumbar fusion procedures in patients with opioid use disorders: a step toward improving enhanced recovery protocols for a unique patient population". Neurosurgical Focus 46, n.º 4 (abril de 2019): E12. http://dx.doi.org/10.3171/2019.1.focus18652.
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OBJECTIVEThe authors set out to conduct the first national-level study assessing the risks and outcomes for different lumbar fusion procedures in patients with opioid use disorders (OUDs) to help guide the future development of targeted enhanced recovery after surgery (ERAS) protocols for this unique population.METHODSData for patients with or without OUDs who underwent an anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), or lateral transverse lumbar interbody fusion (LLIF) for lumbar disc degeneration (LDD) were collected from the 2013–2014 National (Nationwide) Inpatient Sample database. Multivariable logistic regression was implemented to analyze how OUD status impacted in-hospital complications, length of hospital stay, discharge disposition, and total charges by procedure type.RESULTSA total of 139,995 patients with LDD were identified, with 1280 patients (0.91%) also having a concurrent OUD diagnosis. Overall complication rates were higher in OUD patients (48.44% vs 31.01%, p < 0.0001). OUD patients had higher odds of pulmonary (p = 0.0006), infectious (p < 0.0001), and hematological (p = 0.0009) complications. Multivariate regression modeling of outcomes by procedure type showed that after ALIF, OUD patients had higher odds of nonhome discharge (p = 0.0007), extended hospitalization (p = 0.0002), and greater total charges (p = 0.0054). This analysis also revealed that OUD patients faced higher odds of complication (p = 0.0149 and p = 0.0471), extended hospitalization (p = 0.0439 and p = 0.0001), and higher total charges (p < 0.0001 and p < 0.0001) after PLIF and LLIF procedures, respectively.CONCLUSIONSObtaining a better understanding of the risks and outcomes that OUD patients face perioperatively is a necessary step toward developing more effective ERAS protocols for this vulnerable population. This study, which sought to characterize the outcome profiles for lumbar fusion procedures in OUD patients on a national level, found that this population tended to experience increased odds of complications, extended hospitalization, nonhome discharge, and higher total costs. Results from this study warrant future prospective studies to better the understanding of these associations and to further the development of better ERAS programs that may improve patient care and reduce cost burden.
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Yao, Xiaocong, Lin Chen, Huihui Xu y Zhongxin Zhu. "The Association between Serum Uric Acid and Bone Mineral Density in Older Adults". International Journal of Endocrinology 2020 (29 de junio de 2020): 1–7. http://dx.doi.org/10.1155/2020/3082318.
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Objectives. Uric acid has been found to be potentially protective in bone metabolism. We investigated the relationship between serum uric acid (sUA) and lumbar bone mineral density (BMD) among 4156 participants aged 60 years and over from the National Health and Nutrition Examination Survey (NHANES). Methods. To estimate the association between sUA and lumbar BMD, multivariate logistic regression analyses were conducted. Fitted smoothing curves and generalized additive models were also performed. Results. We found sUA positively correlated with lumbar BMD after adjusting for other confounders. On subgroup analyses, stratified by sex and race/ethnicity, the positive correlation of sUA with lumbar BMD remained in both men and women, as well as in whites and Mexican Americans, but not in blacks. In blacks, the association of sUA with lumbar BMD was an inverted U-shaped curve (inflection point: 7.5 mg/dL). Conclusions. Our study revealed a positive relationship between sUA and lumbar BMD among most old adults. This association followed an inverted U-shaped curve among blacks.
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Guppy, Kern H., Priscilla H. Chan, Heather A. Prentice, Elizabeth P. Norheim, Jessica E. Harris y Harsimran S. Brara. "Does the use of preoperative bisphosphonates in patients with osteopenia and osteoporosis affect lumbar fusion rates? Analysis from a national spine registry". Neurosurgical Focus 49, n.º 2 (agosto de 2020): E12. http://dx.doi.org/10.3171/2020.5.focus20262.
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OBJECTIVEBisphosphonates are used to increase bone strength in treating osteopenia and osteoporosis, but their use for increasing lumbar fusion rates has been controversial. The objective of this study was to determine if preoperative treatment with bisphosphonates affects the reoperation rates for nonunions (operative nonunion rates) following lumbar fusions in patients with osteopenia or osteoporosis.METHODSThe authors conducted a cohort study using data from the Kaiser Permanente Spine Registry. Patients (aged ≥ 50 years) with a diagnosis of osteopenia or osteoporosis who underwent primary elective lumbar fusions for degenerative disc disease, deformity, or spondylolisthesis were included in the cohort. Repeated spinal procedures at the index lumbar levels were noted through chart review. Reoperations for symptomatic nonunions (operative nonunions), time to nonunion, and the nonunion spine level(s) were also identified. The crude 2-year cumulative incidence of operative nonunions was calculated as 1 minus the Kaplan-Meier estimator. Cox proportional hazard regression was used to evaluate the association between preoperative bisphosphonate use and operative nonunion after adjustment for covariates. Analysis was stratified by osteopenia and osteoporosis diagnosis.RESULTSThe cohort comprised 1040 primary elective lumbar fusion patients, 408 with osteopenia and 632 with osteoporosis. Ninety-seven (23.8%) patients with osteopenia and 370 (58.5%) patients with osteoporosis were preoperative bisphosphonate users. For the osteopenia group, no operative nonunions were observed in patients with preoperative bisphosphonate, while the crude 2-year incidence was 2.44% (95% CI 0.63–4.22) in the nonuser group. For the osteoporotic group, after adjustment for covariates, no difference was observed in risk for operative nonunions between the preoperative bisphosphonate users and nonusers (HR 0.96, 95% CI 0.20–4.55, p = 0.964).CONCLUSIONSTo the authors’ knowledge, this study presents one of the largest series of patients with the diagnosis of osteopenia or osteoporosis in whom the effects of preoperative bisphosphonates on lumbar fusions were evaluated using operative nonunion rates as an outcome measure. The results indicate that preoperative bisphosphonate use had no effect on the operative nonunion rates for patients with osteoporosis. Similar indications were not confirmed in osteopenia patients because of the low nonunion frequency. Further studies are warranted to the determine if preoperative and postoperative timing of bisphosphonate use has any effect on lumbar fusion rates.