Hardwood Ebooks Catalog
1.0 Softwoods and Hardwoods Wood dust is any particle arising from processing or handling wood (1). Woods are classified into two broad botanical classifications hardwood is the common name given to the botanical classification Angiosperms, and softwood is the common name given to the botanical classification Gymnosperms. Gymnosperms have exposed seeds whereas angiosperms have encapsulated seeds. Although there are more than 12,000 species of trees recorded, most species are deciduous trees or hardwoods, and only about 800 species are coniferous trees or softwoods (2). Table 17.1 summarizes nomenclature for the more typical softwoods and hardwoods.
Considering our future situation with respect to plant drugs, we can observe some striking polarities. There is a global population which is anticipated to reach at least 9 billion by 2050, and a rapidly increasing technology base in the areas of automation and biological assessment. By contrast, bio- (and therefore chemo)-diversity in the world's hardwood forests is being irreversibly degraded at an alarming rate. And finally, oil stocks, a staple for the production of synthetic drugs, are projected to last only another 70-75 years at current rates of usage.
This is a tumour with histological features resembling colorectal adenocarcinoma 126, 220 . It is considered to originate through intestinal metaplasia of the ciliated respiratory cells lining the schneiderian membrane. This tumour is the most common type of sinonasal adeno-carcinoma, representing about 6-13 of malignancies developing in the sinonasal tract 41, 105, 216 . Metastasis from gastrointestinal adenocarcinoma should be ruled out before a tumour is labelled as a primary of this region. These tumours are strongly associated with exposure to different types of dust, mainly hardwood, but also softwood dusts, as well as leather dust 4, 5, 47, 102, 123, 124, 142 . About 20 of sinonasal intestinal-type adenocarcinomas seem to be sporadic, without evidence of exposure to industrial dusts 4 .
The drug is derived from plants that grow mostly on hardwoods (ssp. album), in rare cases also on fir (ssp. abietis) and on pine (ssp. austriacum). The shoots have no significant odour and a slightly tart taste. The viscous fruits are of a sweetish, slightly bitter taste. The bushes easily break at the nodes. The shoots repeatedly ramified in form of a dichasium are round or slightly flattened. The internodes reach a length of up to 80 mm and are up to 4 mm in diameter in the middle. The surface is smooth, bare and of dark green colour twigs of ssp. austriacum are often yellow green. They emerge in the axil of a pair of two oppositely inserted scale leaves with a narrow, reddish border and whitish, fringed leaf margin. The terminal shoots culminate in an inflorescence head of up to 7 mm length usually with three male or of female flower buds, which are surrounded by thick scaled leaves.
Adenocarcinoma of the ethmoid and the woodworking trade (especially hardwood exposure) began in 1965 in the UK 17,18 . The increased relative risk is similar to that for carcinoma of the bronchus in smokers, with a cumulative life-time risk of 1 in 120 and a 500-1,000 times greater risk than the general population of developing the condition. It became a recognized industrial disease in the UK in 1969.
The resistance phenomenon is of critical importance for an effective mistletoe cultivation. The hypothesis that resistance of oaks could be overcome only by the virulence of selected mistletoe seed could be ruled out. Seeds from any hardwood mistletoe (V. album ssp. album) could become established on mistletoe-receptive oaks. It was found that mistletoe resistance appears to be genetically fixed by the host tree (Grazi and Urech 1983). The work of Frochot et al. (1978) had already suggested that the resistance might be bound up with the trees' genetic constitution.
Talc is an extremely versatile mineral that has found a number of uses despite the relative impurity of most of the ores mined. Except for pure steatite grades, hand-picked, platy, cosmetic talcs and a few products from wet processing plants, industrial products are mixtures of many minerals. The principal uses are as an extender and filler pigment in the paint industry for coating and filling paper in ceramic products and as a filler for plastics and roofing products. Miscellaneous uses of talc include binders and fillers in textiles fillers in integral, foamed, latex rubber backings for carpets, rugs, and parquet hardwood floor panels filler for upholstery fabric backing and draperies lubricant in extreme temperature range greases corrosion proofing composition 10-15 in dry fire extinguishing powders loading and bleaching materials such as cotton sacks, cordage, and rope string cereal polishing bleaching agents food odor absorber floor wax water filtration leather treatment joint...
The wall is usually made of locally available material, for example, corrugated sheets, split logs, timber planks, mud and sticks, or woven thatch. Plywood, hardboard, or even card-board from old boxes is often used in slum areas where better material cannot be afforded. Most types of walls having cracks or crevices or spaces between planks, stones, or logs provide excellent undisturbed refuges for a number of ectoparasites, vectors, and pests. The few, if any, windows ensure a dark, poorly ventilated, usually humid environment where the arthropods will thrive.
The current costs and time to develop a new drug are substantial. It has been estimated to take 12 to 15 years and 250 to 500 million for a new chemical entity to reach the market (DiMasi et al., 1991 DiMasi, 1994). Pharma-cogenomics offers the opportunity to reduce these figures by improving the drug discovery and clinical trial processes. Currently, failure rates during preclinical and clinical phases of drug development are very high (Sander, 1978). Typical statistics from the pharmaceutical industry suggest that only one of every 10,000 molecules synthesized becomes a marketed medicine. This high failure rate becomes even more abysmal when market success is measured in dollar sales. It has been estimated that only about one in 60,000 compounds synthesized by pharmaceutical companies can be regarded as highly successful (i.e., global sales in excess of 100 million) (Redwood, 1993). Moreover, only about 12 of the drugs that enter the human testing phases of drug development ever...
Xylanases have been shown to aid in the bleaching of many different softwoods and hardwoods 18, 86 . Both chemical and mechanical pulps have benefited by xylanase treatment 18 . Since the first description of the use of xylanase to boost the bleaching of pulps 87 , there has been an acceleration in the identification of new xylanases and continuing research into developing xylanases that are more suitable for the elevated temperatures, alkaline pH, and other conditions (presence of proteases) in the stages where the enzyme is used 18, 86, 88-90 .
The application of dielectric-barrier discharge to lignocellulosic materials for improved dry-strength performance was reported (1967) and patented (1969) by Goring 12, 51 . Pressing together layers of surface-treated cellulose acetate films or sheets formed from bleached hardwood and softwood kraft fibers increases the bond strength between laminates 11, 12, 43, 52 . The adhesion between treated laminates of wood, cellulose films, or paper with treated synthetic polymers can also be improved via dielectric-barrier discharge 11, 53 . Chemical additives impact this process, as the benefits to adhesion between paper and polyethylene upon surface treatment are enhanced in the presence of starch 54 while calcium carbonate fillers reduce adhesion 55 . Dielectric-barrier discharge is also applied to improving the adhesion of glues 56 , paints 24 , and inks 57 to lignocellulosic fibers. For example, the adhesion of toner ink to paper 57 can be enhanced by dielectric discharge in a photocopy...
Inhalation of soap-bark dust has caused occupational asthma. This wood dust is a product of the Quillaja tree and is used in the manufacture of saponin, a surface-reducing agent. Soap-bark is chemically related to acacia and tragacanth, and these gums showed cross-reactivity in the soap-bark RAST ( 251).
Occupational exposure to wood dust, in particular to dust of hard woods such as beech and oak, is the main known risk factor for sinonasal cancer. The increase in risk (in the order of 5-50 fold) is strongest for adenocarcinomas and for cancers originating from the sinuses. The effect is present after 40 or more years since first exposure and persists after cessation of exposure. An increased risk of sinonasal cancer has been shown among workers in nickel refining and chromate pigment manufacture, but not among workers exposed to these metals in other processes, such as plating and welding. Among other suspected occupational carcinogens are formaldehyde, diisopropyl sulfate and dichloroethyl sulfide.
2 International Agency for Research on Cancer (IARC), Wood dust and formaldehyde. IARCMonogra. Eval. Carcinog. Risks Hum. 62, 37, 49, 103, 137, 147, 159, 177, 263-266 (1995). 3 L. A. Nylander and J. M. Dement, Carcinogenic effects of wood dust Review and discussion. Am. J. Ind. Med. 24, 619-647 (1993). 8 Y. S. Al Zuhair, C. J. Whitaker, and F. F. Cinkoati, Ventilatory function in workers exposed to tea and wood dust. Bri. J. Ind. Med. 38, 339-345 (1981). 9 L. W. Whitehead, T. Freund, and L. L. Hahn, Suspended dust concentrations and size distributions and quantitative analysis of inorganic particles from woodworking operations. Am. Ind. Hyg. Assoc. J. 42, 461-467 (1981). 10 H. C. Andersen, I. Andersen, and J. Solgaard, Nasal cancers, symptoms and upper airway function in woodworkers. Br. J. Ind. Med. 34, 201-207 (1977). 11 A. M. Sass-Kortsak et al., Wood dust and formaldehyde exposures in the cabinet-making industry. Am. Ind. Hyg. Assoc. J. 47, 747-753 (1986). 12 D. L. Pisaniello, K....
During epidemic viral encephalitis, only a minority of those infected develop encephalitis. Others develop viral meningitis, fever and headache only, or no symptoms at all. These diseases are all zoonoses maintained in nature in birds or rodents, humans being an accidental host. In the United States, LaCrosse encephalitis virus usually causes most of the reported encephalitis cases. In its natural cycle (figure 26.13), the LaCrosse virus infects Aedes mosquitoes, which pass it directly from one mosquito to another in semen, and it can survive the winter in the mosquito's eggs. These mosquitoes feed on and infect squirrels and chipmunks, which markedly amplify the amount of virus and spread it to uninfected female mosquitoes feeding on the rodents' blood. These mosquitoes are forest dwellers that normally breed in water-containing cavities in hardwood trees or in discarded tires.
Transverse section of slime-enveloped seed of hardwood-grown mistletoe (Viscum album ssp. album). Green endosperm enveloped in whitish, translucent mesocarp, with one embryo embedded in it, its hypocotyl pointing to the periphery (x9). B. Transverse section of an apple tree branch with a growing embryo of Visucm album on it. In the autumn, the sinker has become embedded in the wood of the host which responds with hypertrophic growth (x10). C. Part of mistletoe sinker in an apple tree branch, tangential section, stained with astral blue safranin red. Host wood brownish, with light-coloured vascular strands coming in from the left. On the right the light-coloured sinker parenchyma, with dark xylem structures growing into it from the periphery, where host xylem and sinker tissue meet. These structures join to form a central vascular strand (x33). D. Longitudinal section of a secondary sinker of V. album ssp. album growing from a cortical strand (top, dark green). The sinker...
Scalbert et al. (1989) described the chromatographic separation of cyanidin and delphinidin from methanolic extracts of oak heartwood using a C-18 Novapak column. The elution solvent was a mix of two solvents A and B that changed in composition from 0-100 B in a linear fashion over a period of 20 min. Solvent A was a mixture of 94 5 1 H2O methanol H3PO4, and solvent B was 99 1 methanol H3PO4, at a flow rate of 1.7mL min. In this case a dual-channel spectrophotometer was used with two wavelengths selected for detection 280 and 530 nm. Under these conditions, and based on reference compounds, delphinidin eluted after 13.9 min and cyanidin after 14.8 min.
The mechanism of injury is an eccentric loading of the biceps muscle that can occur as a result of actions, such as suddenly lifting a heavy load, catching a heavy load, carrying an unbalanced object, or reaching up to prevent a fall. Ruptures also occur following relatively routine activities, such as throwing a football, carrying a large sheet of plywood, or going for a slap shot while playing hockey. The association of biceps tendon ruptures with relatively routine activities suggests that the problem may be due to chronic attritional tears that eventually weaken the distal biceps tendon. Degeneration of the tendon identified at the time of surgery and shreds of tendinous material still attached to the radial tuberosity support this supposition.5'7'8
- V. album L. ssp. platyspermum Kell. (ssp. album) growing on hardwood trees Earlier reports (Freudenberg 1968) that lignins from mistletoes grown on softwood trees (ssp. abietis and ssp. laxum) contain coniferous lignin, whereas lignin from mistletoes grown on hardwood trees (ssp. album) produce hardwood lignin could not been proven (Becker and Nimz 1974). Some hardwood trees (e.g. beech, boxtree) are resistant to mistletoe infections other species e.g. European elm (Ulmus campestris and U. montana) and European oak (Quercus robur and Qu. petraea) are rarely infected by mistletoe. However, if an infection is successful for one tree this tree can host several mistletoe bushes (Ramm et al., this book). A detailed list of host trees of Viscum album ssp. platyspermum is listed in Luther and Becker (1987). Hariri et al. (1991, 1992) studied different trees that were known to have different resistances to mistletoe infections. A histocytological observation demonstrated that two barriers...
Biomes are distinguished by the presence of characteristic plants and animals, but they are commonly identified by their dominant plant life. For example, hardwood trees, such as oaks and maples, are the dominant form of plant life in the deciduous forest biome. Most ecologists recognize eight major biomes, shown on the map in Figure 21-1, and several minor biomes. In this section, you will learn about the characteristics of these major biomes tundra, tropical forest, temperate forest, taiga, temperate grassland, savanna, chaparral, and desert.
The LB group of species are considerably less discriminating in their vector choices than the agents of RF. The sole reservoirs for this group of Borrelia spp. appear to be vertebrates rather than ticks alone or both ticks and vertebrates. In a vertebrate host, such as a rodent in a hardwood forest in Connecticut or Switzerland, there may be more than one Ixodes species that parasitize these animals. Restriction of the Borrelia sp. to only one of the ticks would limit opportunities for transmission. The availability of a variety of vertebrate hosts and tick vectors may obviate the need for transovarial transmission, which possibly may have a fitness cost to either the ticks through decreased fecundity or to Borrelia through diversion of some organisms to the ova rather than the salivary glands.
The causal relationship of wood dust and leather dust with the development of sinonasal ITACs has been established by several epidemiological studies from different countries 1594 . In this setting, dust particle size is important because those smaller than 5 jm reach the lower respiratory tract, while larger particles are accumulated in the nasal mucosa. However, the carcinogens involved in the onset of ITACs in wood workers and leather workers have not yet been clearly identified. Biologically active substances which can be present in wood and leather dusts include alkaloids, saponins, stilbenes, aldehydes, quinones, flavonoids, resins, oil, steroids, terpenes, fungal proteins, and tannins 1341 . II moderately-differentiated, III poorly-differentiated) 799,804,1333 , alveolar goblet type, signet-ring type and transitional type. Either classification is acceptable, but for simplicity the Barnes classification is preferred and will be the one utilized in this description. The most...
BlGFOOT sculpture carved from a redwood stump in the 1960s by Jim McClarin in front of the Willow Creek (California) Chamber of Commerce. (Bill Lewinson PhotoArt by Burro) BlGFOOT sculpture carved from a redwood stump in the 1960s by Jim McClarin in front of the Willow Creek (California) Chamber of Commerce. (Bill Lewinson PhotoArt by Burro) A five-second video recording of a Bigfoot taken by a television film crew on August 28, 1995, in the Jedediah Smith Redwoods State Park near Crescent City, California, is interesting, if inconclusive. It shows a massive, hairy, black creature with a distinctly erect penis.
Association for Applied Psychophysiology and Biofeedback, 10200 West 44th Avenue, Suite 304, Wheat Ridge, Colorado 80033, 303-4228436 Center for Applied Psychophysiology, Menninger Clinic, P.O. Box 829, Topeka, Kansas 66601, 913-273-7500 ext. 5375 Tools for Exploration, 4460 Redwood Highway, Suite 2, San Rafael, California 94903, 415-499-9050.
Stem cells in plants are located in meristems, populations of undifferentiated cells found at the tips of growing shoots. Shoot apical meristems (SAMs) produce leaves and shoots, and of course more stem cells that constitute the nearly immortal meristems. Meristems can persist for thousands of years in long-lived species such as redwood trees and bristlecone pines. As a plant grows, the cells left behind the meristems are encased in rigid cell walls and can no longer grow. SAMs can split to form branches, each branch with its own SAM, or be converted into floral meristems (Figure 22-6). Floral meristems give rise to the four floral organs sepals, stamens, carpels, and petals that form flowers. Unlike SAMs, floral meristems are gradually depleted as they give rise to the floral organs.
The Complete Guide To Wood Finishing
Wood finishing can be tricky and after spending hours on building your project you want to be sure that you get the best outcome possible. In The Complete Guide To Wood Finishing you will learn how to get beautiful, professional results no matter what your project is, even if you have never tried your hand at wood finishing before. You will learn about every step in the wood finishing process from a professional wood finisher with years of experience.