Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Wood

  • dead wood
  • decaying wood
  • fossil wood
  • fuel wood
  • large wood
  • oak wood
  • pine wood
  • poplar wood
  • reaction wood
  • small wood
  • solid wood
  • tension wood

  • Terms modified by Wood

  • wood accumulation
  • wood addition
  • wood anatomy
  • wood ant
  • wood biomass
  • wood chip
  • wood component
  • wood composite
  • wood density
  • wood dust
  • wood dust exposure
  • wood extract
  • wood fiber
  • wood fibre
  • wood flour
  • wood flour composite
  • wood flour content
  • wood formation
  • wood frog
  • wood johnson foundation
  • wood material
  • wood mouse
  • wood particle
  • wood plastic composite
  • wood production
  • wood products
  • wood ratio
  • wood sample
  • wood species
  • wood specific gravity
  • wood structure
  • wood surface
  • wood system
  • wood type

  • Selected Abstracts


    ARCHAEOMETRY, Issue 4 2010
    A series of 112 waterlogged archaeological wood samples of different provenances, wood species, burial times and states of preservation were analysed with the aim of assessing the validity (in terms of limits and reliability) of procedures conventionally used in the pulp and paper industry, to evaluate the state of preservation of decayed wood. In particular, the extent of any damage wrought on decayed wood tissue by the repetitive cycles that characterize these procedures was evaluated as a function of the degradation of the samples. The results indicated that standard methodologies give reliable measurements regardless of the extent of wood decay. However, it is essential to compare these data with those of non-decayed wood that has been measured using the same procedures to take account of the errors that are inherent in these methodologies and that affect measurements. [source]

    Cost-Efficiency of Decaying Wood as a Surrogate for Overall Species Richness in Boreal Forests

    biodiversidad; gestión de bosques; indicadores de riqueza de especies; seleccion de sitios Abstract:,Decaying wood is one of the most important elements for species richness in boreal forests. We tested how well reserve selection based on the amount and quality of decaying wood results in a representation of four ecologically different taxa (beetles, birds, wood-inhabiting fungi, and vascular plants). We also compared the cost-efficiency of the use of dead-wood indicators with comprehensive species inventory. Our database included 32 seminatural old-forest stands located in northern Finland. Decaying wood was a relatively good indicator of saproxylic species but not overall species richness. Even though dead wood did not reflect accurately overall species richness, our results indicated that the use of decaying wood as an indicator in site selection was more cost-efficient than using information from large-scale species inventories. Thus, decaying wood is a valuable surrogate for species richness, but other cost-efficient indicators that reflect the requirements of those species which are not dependent on decaying wood should be identified. Resumen:,La madera en descomposición es uno de los elementos importantes para la riqueza de especies en bosques boreales. Probamos como resulta la selección de reservas con base en la cantidad y calidad de madera en descomposición en la representación de cuatro taxa ecológicamente distintos (escarabajos, aves, hongos habitantes en la madera y plantas vasculares). También comparamos la rentabilidad del uso de indicadores de madera muerta con inventarios integrales de especies. Nuestra base de datos incluyó 32 sitios de bosque maduro seminatural localizados en el norte de Finlandia. La madera en descomposición fue un indicador relativamente bueno de especies saproxílicas pero no de la riqueza total. Aunque la madera en descomposición no reflejó la riqueza total con precisión, nuestros resultados indicaron que el uso de madera en descomposición como un indicador en la selección de sitios fue más rentable que el uso de información de inventarios de especies de gran escala. Por lo tanto, la madera en descomposición es un sustituto valioso de la riqueza de especies, pero se deben identificar otros indicadores rentables que reflejen los requerimientos de aquellas especies que no dependen de la madera en descomposición. [source]

    An Ecological and Economic Assessment of the Nontimber Forest Product Gaharu Wood in Gunung Palung National Park, West Kalimantan, Indonesia

    Gary D. Paoli
    We studied the demographic effect and economic returns of harvesting aromatic gaharu wood from fungus-infected trees of Aquilaria malaccensis Lam. at Gunung Palung National Park, Indonesia, to evaluate the management potential of gaharu wood. Aquilaria malaccensis trees openface> 20 cm in diameter occurred at low preharvest densities (0.16,0.32 ha) but were distributed across five of six forest types surveyed. During a recent harvest, 75% of trees were felled, with harvest intensities ranging from 50% to 100% among forest types. Overall, 50% of trees contained gaharu wood, but trees at higher elevations contained gaharu wood more frequently ( 73%) than trees at lower elevation (27%). The mean density of regeneration ( juveniles> 15 cm in height) near adult trees (3,7 m away) was 0.2/m2, 200 times greater than at random in the forest (10/ha), but long-term data on growth and survivorship are needed to determine whether regeneration is sufficient for population recovery. Gaharu wood extraction from Gunung Palung was very profitable for collectors, generating an estimated gross financial return per day of US $8.80, triple the mean village wage. Yet, the estimated sustainable harvest of gaharu wood at natural tree densities generates a mean net present value of only $10.83/ha, much lower than that of commercial timber harvesting, the dominant forest use in Kalimantan. Returns per unit area could be improved substantially, however, by implementing known silvicultural methods to increase tree densities, increase the proportion of trees that produce gaharu wood, and shorten the time interval between successive harvests. The economic potential of gaharu wood is unusual among nontimber forest products and justifies experimental trials to develop small-scale cultivation methods. Resumen: Datos ecológicos y económicos son esenciales para la identificación de productos forestales no maderables tropicales con potencial para la extracción sostenible y rentable en un sistema bajo manejo. Estudiamos el efecto demográfico y los beneficios económicos de la cosecha de la madera aromática gaharu de árboles de Aquilaria malaccenis Lam infectados por hongos en el Parque Nacional Gunung Palung Indonesia para evaluar el potencial de manejo de la madera. Arboles de Aquilaria malaccenis> 20 cm de diámetro ocurrieron en bajas densidades precosecha (0.16,0.32 ha,1) pero se distribuyeron en cinco de los seis tipos de bosque muestreados. Durante una cosecha reciente, 75% de los árboles fueron cortados, con intensidades de cosecha entre 50 y 100% en los tipos de bosque. En conjunto, 50% de los árboles contenían madera gaharu, pero árboles de elevaciones mayores contenían madera gaharu más frecuentemente ( 73%) que árboles de elevaciones menores (27%). La densidad promedio de regeneración ( juveniles> 15 cm de altura) cerca de árboles adultos (de 3 a 7 m de distancia) fue de 0.2 m,2, 200 veces mayor que en el bosque (10 ha,1), pero se requieren datos a largo plazo sobre el crecimiento y la supervivencia para determinar si la regeneración es suficiente para la recuperación de la población. La extracción de madera gaharu de Gunung Palung fue muy redituable, generando un rendimiento financiero bruto estimado en US $8.80 diarios, el triple del salario promedio en la zona. Sin embargo, la cosecha sostenible estimada de madera gaharu en densidades naturales de árboles genera un valor presente neto de sólo $10.83 ha,1, mucho menor que el de la cosecha comercial de madera, uso dominante del bosque en Kalimantan. Sin embargo, los rendimientos por unidad de área podrían mejorar sustancialmente mediante la instrumentación de métodos silviculturales para incrementar la densidad de árboles, incrementar la proporción de árboles que producen madera gaharu y reducir el intervalo de tiempo entre cosechas sucesivas. El potencial económico de la madera gaharu es poco usual entre los productos forestales no maderables y justifica la experimentación para desarrollar métodos de cultivo en pequeña escala. [source]

    Design Experience: Transforming Fragile Ideas Into Innovative Products

    Bruce Wood
    Transplanting a Scottish model, in 2001 the Centro de Design do Paraná, in Brazil, initiated grants to underwrite the hiring of industrial designers. Bruce Wood, Geraldo Pougy, and Gisele Raulik describe how the goal was, within an 18-month timeframe, to exhibit 20 promising production prototypes. By August 2002, there were 41 prototypes on display and 40 local companies that could literally see the potential of design to improve business. [source]

    Wood distribution in neotropical forested headwater streams of La Selva, Costa Rica

    Daniel Cadol
    Abstract Surveys of wood along 30 forested headwater stream reaches in La Selva Biological Station in north-eastern Costa Rica represent the first systematic data reported on wood loads in neotropical streams. For streams with drainage areas of 0·1,8·5 km2 and gradients of 0·2,8%, wood load ranged from 3 to 34·7 m3 wood/100 m channel and 41,612 m3 wood/ha channel. These values are within the range reported for temperate streams. The variables wood diameter/flow depth, stream power, the presence of backflooding, and channel width/depth are consistently selected as significant predictors by statistical models for wood load. These variables explain half to two-thirds of the variability in wood load. These results, along with the spatial distribution of wood with respect to the thalweg, suggest that transport processes exert a greater influence on wood loads than recruitment processes. Wood appears to be more geomorphically effective in altering bed elevations in gravel-bed reaches than in reaches with coarser or finer substrate. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    A conceptual model for the longitudinal distribution of wood in mountain streams

    Ellen Wohl
    Abstract Wood load, channel parameters and valley parameters were surveyed in 50 contiguous stream segments each 25 m in length along 12 streams in the Colorado Front Range. Length and diameter of each piece of wood were measured, and the orientation of each piece was tallied as a ramp, buried, bridge or unattached. These data were then used to evaluate longitudinal patterns of wood distribution in forested headwater streams of the Colorado Front Range, and potential channel-, valley- and watershed-scale controls on these patterns. We hypothesized that (i) wood load decreases downstream, (ii) wood is non-randomly distributed at channel lengths of tens to hundreds of meters as a result of the presence of wood jams and (iii) the proportion of wood clustered into jams increases with drainage area as a result of downstream increases in relative capacity of a stream to transport wood introduced from the adjacent riparian zone and valley bottom. Results indicate a progressive downstream decrease in wood load within channels, and correlations between wood load and drainage area, elevation, channel width, bed gradient and total stream power. Results support the first and second hypotheses, but are inconclusive with respect to the third hypothesis. Wood is non-randomly distributed at lengths of tens to hundreds of meters, but the proportion of pieces in jams reaches a maximum at intermediate downstream distances within the study area. We use these results to propose a conceptual model illustrating downstream trends in wood within streams of the Colorado Front Range. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Wood storage in a wide mountain river: case study of the Czarny Dunajec, Polish Carpathians

    omiej Wy
    Abstract Storage of large woody debris in the wide, mountain, Czarny Dunajec River, southern Poland, was investigated following two floods of June and July 2001 with a seven-year frequency. Within a reach, to which wood was delivered only by bank erosion and transport from upstream, wood quantities were estimated for eighty-nine, 100 m long, channel segments grouped into nine sections of similar morphology. Results from regression analysis indicated the quantity of stored wood to be directly related to the length of eroded, wooded banks and river width, and inversely related to unit stream power at the flood peak. The largest quantities of wood (up to 33 t ha,1) were stored in wide, multi-thread river sections. Here, the relatively low transporting ability of the river facilitated deposition of transported wood while a considerable length of eroded channel and island banks resulted in a large number of trees delivered from the local riparian forest. In these sections, a few morphological and ecological situations led to the accumulation of especially large quantities of wood within a small river area. Very low amounts of wood were stored in narrow, single-thread sections of regulated or bedrock channel. High stream power facilitated transport of wood through these sections while the high strength of the banks and low channel sinuosity prevented bank retreat and delivery of trees to the channel. Considerable differences in the character of deposited wood existed between wide, multi-thread channel sections located at different distances below a narrow, 7 km long, channellized reach of the river. Wood deposited close to the downstream end of the channellized reach was highly disintegrated and structured into jams, whereas further downstream well preserved shrubs and trees prevailed. This apparently reflects differences in the distance of wood transport and shows that in a mountain river wider than the height of trees growing on its banks, wood can be transported long distances along relatively narrow, single-thread reaches but is preferentially deposited in wide, multi-thread reaches. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Genome sequence of Desulfobacterium autotrophicum HRM2, a marine sulfate reducer oxidizing organic carbon completely to carbon dioxide

    Axel W. Strittmatter
    Summary Sulfate-reducing bacteria (SRB) belonging to the metabolically versatile Desulfobacteriaceae are abundant in marine sediments and contribute to the global carbon cycle by complete oxidation of organic compounds. Desulfobacterium autotrophicum HRM2 is the first member of this ecophysiologically important group with a now available genome sequence. With 5.6 megabasepairs (Mbp) the genome of Db. autotrophicum HRM2 is about 2 Mbp larger than the sequenced genomes of other sulfate reducers (SRB). A high number of genome plasticity elements (> 100 transposon-related genes), several regions of GC discontinuity and a high number of repetitive elements (132 paralogous genes Mbp,1) point to a different genome evolution when comparing with Desulfovibrio spp. The metabolic versatility of Db. autotrophicum HRM2 is reflected in the presence of genes for the degradation of a variety of organic compounds including long-chain fatty acids and for the Wood,Ljungdahl pathway, which enables the organism to completely oxidize acetyl-CoA to CO2 but also to grow chemolithoautotrophically. The presence of more than 250 proteins of the sensory/regulatory protein families should enable Db. autotrophicum HRM2 to efficiently adapt to changing environmental conditions. Genes encoding periplasmic or cytoplasmic hydrogenases and formate dehydrogenases have been detected as well as genes for the transmembrane TpII- c3, Hme and Rnf complexes. Genes for subunits A, B, C and D as well as for the proposed novel subunits L and F of the heterodisulfide reductases are present. This enzyme is involved in energy conservation in methanoarchaea and it is speculated that it exhibits a similar function in the process of dissimilatory sulfate reduction in Db. autotrophicum HRM2. [source]

    Evaluation of laboratory assays for the assessment of leaching of copper and chromium from ground-contact wood

    Ana I. García-Valcárcel
    Abstract Laboratory studies were conducted to assess the leaching of Cu and Cr from wood, treated with a Cu-Cr-B preservative, when placed in contact with soil. Two laboratory assays were performed: Wood in contact with soil solutions over 30 d, and wood in direct contact with soil over 30 weeks. The influence of several factors, such as soil type and fertilizer use, was studied in both assays. In addition, the effect of soil moisture content and temperature was evaluated when wood was in contact with soil. A discrepancy in the results of the laboratory assays was observed. Leaching of Cu and Cr increased when soil in contact with wood was fertilized, but only an increase of Cu leaching was observed when soil solutions from fertilized soils were used. Moreover, soil solutions from a sandy clay loam soil produced a higher Cu leaching than those from a loamy sand soil, whereas the contrary occurred when treated wood was in direct contact with these soils. In the assay of treated wood in ground contact, the highest metal losses were produced in fertilized soils maintained at constant temperature and high soil moisture content, the latter being the most important factor. These losses were in the range of 5.34 to 15.6% for Cu and 1.85 to 2.35% for Cr in the soils studied. The proposed laboratory assay, using treated wood in direct contact with soil at a moisture content near field capacity during a period of 30 weeks, produced total metal losses that were in accordance with those reported by other authors under field conditions, expressed on a per-year basis. [source]

    Fracture Properties of Wood and Wood Composites

    Stefanie E. Stanzl-Tschegg
    Wood has a complex hierarchical structure and is a kind of polymeric composite with elongated cells in an amorphous matrix. Therefore, fracturing is a complicated process that is influenced by loading mode and direction, humidity, etc. Standard linear-elastic fracture mechanics methods mostly cannot sufficiently quantify fracturing, and combining fracture mechanical with structural investigations at different levels of magnification (centimeter to nanometer levels) helps obtaining insight into the fracture mechanisms. [source]

    Aluminium Metal Matrix Composites Based on Biomorphic Silicon Carbide

    A. Herzog
    Wood can be transformed into silicon carbide (SiC) ceramic by pyrolysing the wood to form a porous carbon template, infiltrating the template with SiO2 sol, and then performing a carbothermal reduction treatment. In this work, such highly-porous ceramised wood replicas were infiltrated with molten aluminium via squeeze casting, thus creating biomorphic metal-matrix composites (MMCs). The microstructure of these novel MMCs were characterised and the mechanical properties examined. [source]

    An Intraday Examination of the Components of the Bid,Ask Spread

    FINANCIAL REVIEW, Issue 4 2002
    Thomas H. McInish
    Using transactions data for a sample of NYSE stocks, we decompose the bid,ask spread (BAS) into order,processing (OP) and asymmetric information (AI) components using the techniques of George, Kaul, and Nimalendran (1991) and Madhavan, Richardson, and Roomans (1997). McInish and Wood (1992) demonstrate that the intraday behavior of BASs can be explained by variables measuring activity, competition, risk, and information. We investigate whether these variables explain the behavior of the OP and AI components of the spread over the trading day. We conclude that, on balance, the variables that determine the aggregate BAS also determine its intraday components. [source]

    Prediction of fire classification for wood based products.

    FIRE AND MATERIALS, Issue 3 2007
    A multivariate statistical approach based on the cone calorimeter
    Abstract Wood has long traditions as a building material, and is often used in construction elements, and as interior and exterior surfaces in the Nordic countries. In most applications, there are reaction to fire requirements to products used as surfaces, e.g. in escape routes and larger public spaces. Most wood products will therefore have to be treated with fire retardant (FR) agents to fulfil the strict requirements to properties connected to heat release and flame spread. Unfortunately, FR agents usually also increase the smoke production, as they cause a more incomplete combustion of the wood. The wood product manufacturers seek to find the optimal amount of FR additives where both heat release and smoke production in the classifying test are within the requirements given in the building regulations. This paper describes models for prediction of the European reaction to fire classes of wood products. The models are based on multivariate statistical analysis, and use test results from the cone calorimeter test as input. The presented models are, with very good precision, able to predict which Euroclass and additional smoke class a wood based product would obtain if it were to be tested in the single burning item test. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    ,The Bombay Debt': Letter Writing, Domestic Economies and Family Conflict in Colonial India

    GENDER & HISTORY, Issue 2 2004
    Erika Rappaport
    Between 1856 and 1861 Minnie Blane and her husband, Captain Archibald Wood, wrote dozens of letters from India to the Minnie's mother in England. These letters and those associated with a military investigation into the couple's relationship in the 1860s detail the connections between the breakdown of the East India Company's rule in India and Minnie Blane's marriage. In particular, this correspondence shows some of the ways in which bourgeois identities were constructed in relationship to money and objects, place and race. It also exposes the fissures between family members, allowing us to see the gender, generational and cultural conflicts within such imperial families. The article raises concerns about the ways in which personal letters have been used as documents in the study of European women's imperial history. [source]

    Non-double-couple mechanisms in the seismicity preceding the 1991,1993 Etna volcano eruption

    A. Saraò
    Summary The temporal evolution of the complete source moment tensor is investigated for 28 earthquakes that occurred at Mt Etna in the period August 1990,December 1991 preceding the biggest eruption of the last three centuries. We perform several tests to check the robustness of the results of inversion considering different frequency ranges and different groups of stations. As well as the selection of good-quality data, the error analysis, statistically significant at the 95 per cent confidence level, is employed to validate the findings of the inversion and to distinguish between physical solutions and artefacts of modelling. For events between 0.3 and 10 km depth, strike-slip mechanisms prevail on normal, inverse and dip-slip mechanisms; this is possibly due to the dyke-induced stress dominating the overall stress field at the surface, producing a continuous switch of the tensile and compressive axes. The regional E,W tension prevails at depth, as indicated by the prevalence of normal mechanisms. An increment of the non-double-couple components is observed immediately before the eruption and can be related to movements of fluids, even though, for some events, the complex interaction between tectonic stress and volcanic activity cannot be excluded. The source time functions retrieved are in general simple and short but some show complexities, as one would expect in volcanic seismicity. From the seismic scalar moment found, we extrapolate an empirical moment,magnitude relation that we compare with other relations proposed for the same area and computed for the duration magnitude and the equivalent Wood,Anderson magnitude. [source]

    The Proprietary Church in the Early Medieval West , By Susan Wood

    HISTORY, Issue 317 2010
    No abstract is available for this article. [source]

    Re: Hill-Rodriguez, D., Messmer, P. R., Williams, P. D., Zeller, R. A., Williams, A. R., Wood, M., & Henry, M. (2009).

    The Humpty Dumpty Falls Scale: A case-control study.
    No abstract is available for this article. [source]

    Comments on the Brenner,Wood Exchange on the Low Countries

    Charles Post
    The exchange between Brenner and Wood on the Low Countries in the early modern period raises a number of theoretical and historical issues relating to the conditions for the emergence of capitalist social-property relations and their unique historical laws of motion. This contribution focuses on three issues raised in the Brenner-Wood exchange: the conditions under which rural house-hold producers become subject to ,market coercion', the potential for ecological crisis to restructure agricultural production, and the relative role of foreign trade and the transformation of domestic, rural class relations to capitalist industrialization. [source]

    Incidence and morphology of the brachioradialis accessorius muscle

    JOURNAL OF ANATOMY, Issue 3 2001
    A separate supernumerary muscle in the lateral cubital fossa originating from the humerus or brachioradialis and inserting into the radius, pronator teres or supinator muscle has been considered as a variation of the brachioradialis muscle (Dawson, 1822; Meckel, 1823; Lauth, 1830; Halbertsma, 1864; Gruber, 1868b; Testut, 1884; LeDouble, 1897; Spinner & Spinner, 1996). However, a similar description was used to report additional heads of the brachialis or biceps brachii muscles (Gruber, 1848; Wood, 1864, 1868; Macalister, 1864,66, 1966,69, 1875; Gruber, 1868a; Wolff-Heidegger, 1937). The innervation of these variant muscles would be a good tool to assign each variation to its associated muscle. Consequently, innervation by the radial nerve would indicate that it is a derivative of the humero,radialis group of muscles, while innervation by the musculocutaneous nerve would support it as a derivative of the anterior musculature of the arm (Rolleston, 1887; Lewis, 1989). However, no references to the innervation were found in the available literature. Therefore this study set out to establish the phylogenetic origin of the brachioradialis accessorius muscle and, with the help of its innervation, to determine its incidence and unreported detailed morphology. [source]

    Recent Advances in Human Evolution Research

    JOURNAL OF ANATOMY, Issue 1 2000
    Article first published online: 13 DEC 200
    This isssue of Journal of Anatomy contains review articles based on a Symposium held during a joint meeting of the Anatomical Society of Great Britain and Ireland, the Anatomical Society of South Africa and the Nederlandse Anatomen Vereniging on 15 April 1998 at Rolduc, The Netherlands. The Symposium has been edited by Professor Bernard Wood whose initial review constitutes an introduction to the succeeding articles. [source]

    Temptations of weevil: feeding and ovipositional behaviour of Hylobius warreni Wood on host and nonhost bark in laboratory bioassays

    Gareth R. Hopkins
    Abstract 1Warren root collar weevil Hylobius warreni Wood (Coleoptera: Curculionidae) is a long-lived, flightless insect native to coniferous forests across northern North America. Girdling by larval feeding causes significant mortality on young trees. The insect poses considerable challenges to reforestation. 2Adult weevils feed on all life stages of a variety of coniferous hosts prior to oviposition. Their relative feeding preferences, however, have not been quantified. Moreover, it is not known whether host bark influences oviposition behaviour. 3Feeding preferences of adult weevils were tested in both choice and no-choice laboratory bioassays using small branches from three conifers (lodgepole pine Pinus contorta var. latifolia, interior hybrid spruce Picea glauca×engelmannii, and Douglas-fir Pseudotsuga menziesii) and one deciduous tree (trembling aspen Populus tremuloides). Measurements included the surface area of bark consumed, rate of consumption, the number of days of feeding, and, in the no-choice assay, the number of eggs oviposited. 4Bark consumption was greatest on pine and Douglas-fir, followed by spruce. Little to no feeding occurred on aspen. Consumption did not vary between male versus female insects for any of the feeding metrics quantified. 5The presence of aspen branches did not inhibit feeding on any of the other species in the choice bioassays. 6The number of eggs laid by female insects did not differ significantly among tree species in the no-choice assay. Eggs were laid indiscriminately in the presence of all four host types. 7Results and opportunities for future research are discussed in the context of formulating new integrated pest management strategies for this insect, which is increasingly important in the period of reforestation subsequent to the mountain pine beetle epidemic in western Canada. [source]

    Using the PRISM to Compare the Explanatory Value of General and Role-Contextualized Trait Ratings

    Dustin Wood
    ABSTRACT In an earlier work (Wood & Roberts, 2006), the Personality and Role Identity Structural Model (PRISM) was proposed as a model for organizing the relations between diverse self-perceptions, with a person's general identity ("how I am in general") organized above diverse role identities (e.g., "how I am as an employee"), which in turn is organized above role-specific behaviors and experiences (e.g., typical interactions with coworkers). In the present article, I argue that despite the fact that role trait measures are often much more related to role behaviors than general trait measures in cross-sectional analyses, general trait measures better capture the dispositional causes of a person's role behavior. In support of this, a brief study is presented illustrating how general traits may be better predictors than role-contextualized trait ratings of the evolution of an individual's experiences or behaviors within a given context. Finally, I contend that the basic framework of the PRISM, where a person's behaviors and identities within multiple contexts are assessed simultaneously and longitudinally alongside general personality ratings, is necessary to make strong statements concerning the nature of the relationships between personality traits and role experiences. [source]


    JOURNAL OF PHYCOLOGY, Issue 1 2005
    Hidetoshi Sakayama
    In an attempt to reconstruct the natural taxonomic system for Nitella, 17 species of Nitella subgenus Tieffallenia were reexamined using SEM observations of the internal morphology of the oospore wall (IMOW) and phylogenetic analyses of 4553 base pairs from multiple DNA markers (atpB, rbcL, psaB, and ITS-5.8S rRNA genes). Our SEM observations identified three types of IMOW: homogeneous (HG), weakly spongy (W-SG), and strongly spongy (S-SG) types. Based on differences in the IMOW, species with reticulate or tuberculate oospore wall ornamentation in the external morphology of the oospore wall (EMOW) were subdivided into two distinct groups (characterized by the HG or S-SG types of IMOW, respectively), which were robustly separated from each other in our molecular phylogenetic analyses. In our molecular phylogeny, the subgenus Tieffallenia consisted of four robust monophyletic groups,three clades of the HG type and a spongy (S-SG and W-SG) type clade,that were characterized by differences in the IMOW and EMOW. In addition, our SEM observations and sequence data verified the distinct status of five species (N. japonica Allen, N. oligospira A. Braun, N. vieillardii stat. nov., N. imperialis stat. nov., and N. morongii Allen) that R. D. Wood had assigned as infraspecific taxa. Moreover, our SEM observations of the IMOW also suggested that N. megaspora (J. Groves) Sakayama originally identified by LM includes at least two distinct species, characterized by W-SG and S-SG types of IMOW, respectively. [source]

    Affinities of the freshwater red alga Audouinella macrospora (Florideophyceae, Rhodophyta) and related forms based on ssu rrna gene sequence analysis and pit plug ultrastructure

    JOURNAL OF PHYCOLOGY, Issue 2 2000
    Curt M. Pueschel
    Small subunit rDNA sequencing and transmission electron microscopy were performed to clarify the ordinal affinities of Audouinella macrospora (Wood) Sheath et Burkholder isolates 3394, 3395, and 3603, as well as Chantransia sp. isolate 3585. Culture 3603 is known to produce thalli of Batrachospermum -like morphology under certain culture conditions. Sequence analyses unequivocally placed the three Audouinella macrospora isolates in a clade with Batrachospermum macrosporum Montagne of the Batrachospermales, and Chantransia sp. was found to have affinities with B. louisianae Skuja and B. virgato-decaisneanum Sirodot. The pit plugs of the Audouinella macrospora cultures 3394 and 3395 were nearly identical in size and structure, having thickened plug caps and no cap membranes. Both of these features agree with those of the Batrachospermaceae, with the latter feature showing batrachospermacean rather than acrochaetioid affinities. Pit plugs in the chantransia phase of 3603 were similar, but the plug caps were less well developed. The Batrachospermum phase generated from 3603 had pit plugs that were variable in diameter, according to location in the thallus, thus reflecting the more variable cell size in this phase. Dome-like outer caps, considered typical of Batrachospermum, were present between cells of the determinate lateral filaments. The pit plugs of Chantransia sp. had prominent, dome-like outer caps, but the plug cores were strikingly and consistently smaller in diameter than those of the A. macrospora chantransia cultures, suggesting that plug diameter may be of systematic value in some contexts. [source]

    Some Additional Comments on the Sources and Measurement of the Benefits of Small Business Assistance Programs

    James J. Chrisman
    This article continues a longstanding debate between the authors and Dr. William C. Wood on the usefulness of a particular application of cost-benefit analysis to evaluate small business assistance programs. We provide further discussions of the measurement of primary and secondary benefits with specific reference to the illustrative cases Wood presented in his 1999 article. We then review Wood's suggestions for improvements to small business program evaluations and discuss the progress made in recent evaluations of small business assistance programs. Finally, we reiterate the importance of innovation as an additional source of "secondary" benefits to the economy. [source]

    Generalized Additive Models: an Introduction with R by S. N. Wood

    T. Verbeke
    No abstract is available for this article. [source]

    Influence of Processing Temperature on Microcellular Injection-Moulded Wood,Polypropylene Composites

    Andrzej K. Bledzki
    Abstract Summary: Microcellular wood fibre reinforced polymer materials are significant because of their possibility to reduce the density of automotive components through microcellular structure, process and product part advantages, and as a new development with bio-fibre strengthened plastics. Soft wood fibre reinforced PP composites in box part and panel shape were prepared by an injection moulding process. Polymeric microspheres as a chemical foaming agent (endothermic) were used to produce the microcellular composites. The influence of injection moulding processing temperature on the microcellular structure and properties (tensile and flexural properties, notched charpy impact strength) was investigated by varying the temperature over the 150,170,°C, 160,180,°C and 170,190,°C. A comparative study of cell morphology, weight reduction and mechanical properties was conducted between box part and panel. Microcell morphology, cell size, shape and distribution were investigated using scanning electron micrographs. The results indicated that the lower processing temperature should be below the range of 170,190,°C and processing temperature at 160,180,°C, where the composites showed finer cellular structure compared to other processing temperatures. The mechanical properties did not differ with the variation of processing temperature regardless of composite types (box part or panel). Cellular structure changes in the box part were found considering near or far from injecting point. Microcellular injection-moulded box part (geometry: 150,×,100,×,70 mm3 in size) of soft wood fibre,PP composites. [source]

    Changes in the food of British Barn Owls (Tyto alba) between 1974 and 1997

    MAMMAL REVIEW, Issue 2 2000
    R. Alasdair Love
    ABSTRACT Comparison of the results of a 1993,97 Barn Owl Tyto alba pellet survey with those of a similar survey from 1956,74 showed that Barn Owl diet had changed significantly. The primary differences were a widespread decrease in the percentage of Common Shrew Sorex araneus, combined with an increase in Pygmy Shrew Sorex minutus. The percentage of Wood and Yellow-necked mice Apodemus sylvaticus and A. flavicollis and Bank Vole Clethrionomys glareolus in the diet also increased. Changes in Barn Owl diet since 1974 were independent of land-class group, but were dependent upon region. This was due primarily to a large increase in the percentage of Apodemus spp. in Eastern England. Whilst the percentage of Pygmy Shrew in Barn Owl diet showed significant regional variation, there was no significant variation between land-class groups. The diversity of Barn Owl diet increased between 1974 and 1997, although it was still lower in 1997 than earlier in the century. This increase was dependent upon region, but independent of land-class group. The combined results of both surveys showed significant interland-class group variation in dietary diversity. Changes in diet are discussed in relation to the intensification of agriculture and other changes in land management since the 1970s. The effects on Barn Owls of these changes in prey abundance are discussed, particularly in relation to the decline in Barn Owl numbers during the twentieth century. [source]

    A time-marching finite element method for an electromagnetic scattering problem

    Tri Van
    Abstract In this paper, Newmark time-stepping scheme and edge elements are used to numerically solve the time-dependent scattering problem in a three-dimensional polyhedral cavity. Finite element methods based on the variational formulation derived in Van and Wood (Adv. Comput. Math., to appear) are considered. Existence and uniqueness of the discrete problem is proved by using Babuska,Brezzi theory. Finite element error estimate and stability of the Newmark scheme are also established. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Tension wood as a model for functional genomics of wood formation

    NEW PHYTOLOGIST, Issue 1 2004
    Gilles Pilate
    Summary Wood is a complex and highly variable tissue, the formation of which is developmentally and environmentally regulated. In reaction to gravitropic stimuli, angiosperm trees differentiate tension wood, a wood with specific anatomical, chemical and mechanical features. In poplar the most significant of these features is an additional layer that forms in the secondary wall of tension wood fibres. This layer is mainly constituted of cellulose microfibrils oriented nearly parallel to the fibre axis. Tension wood formation can be induced easily and strongly by bending the stem of a tree. Located at the upper side of the bent stem, tension wood can be compared with the wood located on its lower side. Therefore tension wood represents an excellent model for studying the formation of xylem cell walls. This review summarizes results recently obtained in the field of genomics on tension wood. In addition, we present an example of how the application of functional genomics to tension wood can help decipher the molecular mechanisms responsible for cell wall characteristics such as the orientation of cellulose microfibrils. [source]