91 research outputs found

    Silver fir Abies alba Mill. wood as raw material and tree tissue

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    Predstavljen je pregled zgradbe, lastnosti in rabe lesa jelke (Abies alba Mill.), ki ima neobarvano jedrovino, srednjo gostoto, relativno dobre mehanske lastnosti in je uporaben za številne namene. Vrednost in uporabnost lesa zmanjšujejo predvsem slaba odpornost proti različnim škodljivcem ter pojav mokrega srca in kolesivosti. Lastnosti lesa in uporaba lesa jelke so podobne kot pri smreki (Picea abies Karst.). Jelovina ima prednost predvsem tam, kjer smola ni zaželena, kjer je zaželena odpornost na kisline in baze, ter za vodne konstrukcije. Na primeru dendrokronološko datiranega lesa iz arheoloških in zgodovinskih objektov v Sloveniji smo ugotovili, da so jelovino v preteklosti uporabljali pogosteje kot smrekovino. Dokaz za to so številne do 500 let stare konstrukcije in ostrešja zgodovinskih stavb. Na celičnem nivoju je les jelke sestavljen predvsem iz traheid in parenhimskih celic trakov. V zadnjih letih so bile v Sloveniji opravljene podrobnejše raziskave nastajanja lesa pri jelki, ki so pomembne za fiziologijo drevja in razumevanje lastnosti lesa kot materiala. Opravljenih je bilo tudi več raziskav sekundarnega floema, ki je ključnega pomena za preživetje dreves. Podajamo pregled in glavne ugotovitve teh raziskav.We present the structure, properties and use of European silver fir (Abies alba Mill.) wood, which is known for its uncoloured heartwood, medium density,relatively good mechanical properties and the fact that it can be used for a great variety of products. The value and usefulness of fir wood are reduced due to low resistance against decay and deterioration, and frequent occurrence of wet heart, and ring shakes. The properties of fir wood are comparable to those of Norway spruce (Picea abies Karst.). Fir is favoured where resin is not desired, where durability against acids and bases is important, and for water constructions. We present some examples of wooden constructions in archaeological or historical objects in Slovenia. The dendrochronologically dated wood was up to 500 years old. In the past centuries, fir was used more frequently than Norway spruce. On the cellular level, the wood of fir consists of tracheids and parenchyma cells. In Slovenia, several studies of wood formation have been conducted e in recent years, which are important for a better understanding of the physiology of trees and quality of wood as material. Secondary phloem, which is particularly important for the survival of trees, has been studied as well. We review some main results of such studies

    Anatomy of reaction zones in beech (Fagus sylvatica L.)

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    Pri bukvi (Fagus sylvatica L.) smo raziskovali mejne kompartmentalizacijske plasti izvotljenih ter razkrajajočih se debelnih sredic. Mejne plasti pri vsehpreiskanih drevesih anatomsko ustrezajo reakcijskim conam in ne bariernim conam kot jih predpostavlja model CODIT. V osrednjem delu reakcijske cone so bile traheje intenzivno okludirane z gumoznimi snovmi in suberiziranimi tilami. Lumni trakovnega in aksialnega parenhima, vlaknastih traheid in vse pikenjske odprtine so bili zapolnjeni z netopnimi depoziti. Za notranji del reakcijskih con je značilen razkroj celičnih sten in depozitov, suberizirane strukture pa so ostale nespremenjene. Pri reakcijskih conah, ki mejijo neposredno na duplino, je ta del manjkal, na površini reakcijske cone v duplini so vidna trosišča gliv. Povečana količina škroba v parenhimskih celicah in različne razvojne faze til v zunanjem delu reakcijske cone kažejo na aktivne kompartmentalizacijske procese. Aktivna obrambna in pasivna zaščitna funkcija reakcijskih con v živem drevesu sta podrobneje analizirani.Compartmentalization boundary layers surrounding hollow and decaying stem cores were investigated in beech (Fagus sylvatica L.). In all investigated trees, boundary layers corresponded anatomically to the reaction zones and notto the barrier zones as proposed by the CODIT model. In the central part ofreaction zones, vessels were heavily occluded with deposits of gums and suberised tyloses, whereas the lumina of ray and axial parenchyma, fibre tracheids and all pit apertures were filed with insoluble deposits. The inner part of reaction zones exhibited decay of cell walls and deposits, leaving suberized structures intact. This part was absent in the reaction zones bordering directly on the hollow, although fungal fruit bodies were present onthe surface of the reaction zone. Increased amount of starch grains and different growing stages of tyloses in the outer part of reaction zones indicated active compartmentalization processes. The paper discusses in detailthe active defensive and passive protective function of reaction zones in the living trees

    Response of cambium in Norway spruce (Picea abies) to heating and cooling of stem

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    Proučili smo vpliv eksperimentalnega ogrevanja in hlajenja dela debla navadne smreke (Picea abies) na kambijevo aktivnost in celično diferenciacijo. Poskusasta potekala 30 dniogrevanje od 29.3.2004 do 3.5.2004, hlajenje pa od14.6.2004 do 20.7.2004. Vzorce floema, kambija in ksilema smo iz dreves odvzeli vsakih 10 dni, pripravili prečne prereze tkiv in preparate opazovali ssvetlobnim mikroskopom. Lokalno ogrevanje je po 10 dneh induciralo delitveno aktivnost kambija na floemsko stran, po 20 dneh pa tudi na ksilemsko. Po 30 dneh je pri ogrevanem vzorcu nastalo do 15 celic ranega lesa. V tem času se jeredna delitvena aktivnost kambija pri kontrolnem drevesu šele začela. Odziv kambija na hlajenje debla je bil manj izrazit. Anatomskih razlik med kontrolnim in hlajenim vzorcem po 10 in 20 dneh ni bilo. Po 30 dneh je pri hlajenem vzorcu začel nastajati kasni les, pri kontrolnem drevesu pa šele prehodni rani-kasni les. S poskusom smo demonstrirali, da je mogoče pri smrekiz umetnim ogrevanjem in hlajenjem debla vplivati na ksilo- in floemogenezo.The effect of experimental heating and cooling in a part of the stem of Norwayspruce (Picea abies) on cambial activity and cell differentiation was studied. Experiments were performed for 30 daysheating from 29 March 2004 until 3 May 2004 and cooling from 14 June, 2004 until 20 July 2004. Samples ofphloem, cambium and xylem were taken from trees every 10 days, transverse sections of tissue were prepared and observed under light microscope. After 10days, localized heating reactivated cambial cell division on the phloem sideand after 20 days on the xylem side as well. After 30 days up to 15 early wood cells were formed in the heat-treated sample. Regular cambial activity inthe control tree only started after 30 days. Cambial response to the coolingof the stem was less conspicuous. No anatomical differences were detected between the control and cool-treated samples after 10 and 20 days. After 30 days, late wood already started to form in the cool-treated sample and only transition early-late wood in the control tree. Our experiments demonstrated that it is possible to influence xylo- and phloemogenesis in Norway spruce by experimental heating and cooling of the stem

    Anatomy of wood for bows of string instruments

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    V goslarski delavnici "Atelje Demšar" smo dobili štiri vzorce lesa za godalne loke tujih dobaviteljev, ki so jih označili z imeni (1) pernambuk, (2) konjskomeso, (3) brazil in (4) kačji les. Les smo anatomsko preiskali ter določili vrste: (1) Guilandina echinata (pernambuk, pau brazil, brazil), (2) Manilkara bidentata (massaranduba, konjsko meso), (3) Shorea laevis (balau, bangkirai), (4) Brosimum guianense syn. Piratinera guianensis (Schlangenholz, snakewood, kačji les). Identifikacija je v treh (1, 2 in 4) od štirih primerovpotrdila lesno vrsto, kot jo je navedel dobavitelj lesa. Preiskane lesne vrste pernambuk, konjsko meso in kačji les (1, 2 in 4) iz južne Amerike imajo skupne naslednje lastnosti: fino teksturo, temno obarvano jedrovino, dekorativen videz, visoko gostoto, visoko trdnost, dobro dimenzijsko stabilnost in dobre obdelavnostne lastnosti, posebno struženje in površinsko obdelavo. Vse so zelo cenjene za godalne loke, za najboljšega pa velja les pernambuka. Les balau iz Azije ima slabše lastnosti in ni tipična lesna vrsta za loke. Razlike v zgradbi lesa preiskanih vrst so najverjetneje vzrok za razlike v kvaliteti končnega izdelka. Podajamo opis izdelave lesenega loka, opis lesnih lastnosti in pomen pravilne identifikacije in poimenovanja lesa.Four specimens of wood originating from string instrument bows or from the material intended to be used for the repair of bows were obtained from the string instrument workshop "Atelje Demšar". Foreign wood traders supplied the specimens under their commercial names: (1) pernambouc, (2) horse flesh, (3) brasil, and (4) snakewood. Macroscopic and microscopic wood anatomical investigations were carried out in order to verify the nomenclature of the traded specimens. The microscopic identification provided the following results: (1) Guilandina echinata (pernambouc, pau brazil, brazil), (2) Manilkara bidentata (massaranduba, horse flesh), (3) Shorea laevis (yellow balau, bangkirai), and (4) Brosimum guianense syn. Piratinera guianensis (snakewood). In three cases (1, 2 and 4), the trade names of the provided bow specimens were confirmed by wood anatomical identifications. In case 3, the wood anatomical features fully corresponded to timbers of the botanical species Shorea laevis (yellow balau, bangkirai) from Indomalaysia and not to Guilandina echinata or Caesalpinia spp. from South America. The identified wood species (1, 2 and 4) from South America are characterised by the following properties: fine and decorative texture, high density, good mechanical properties, brown or red coloured heartwood, good working properties (machinability and coating), and good dimensional stability. They are highly appreciated for string instrument bows. Among them, the wood of pernambouc is most valued. The wood of yellow balau, which is distinguished byinferior properties (e.g. excessive shrinkage), is not a typical wood for instrument bows. The fabrication of the bows, the properties of the investigated species and the importance of proper wood identification are presented as well

    Wood formation in beech from two sites at different altitudes

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    Predstavljamo časovno dinamiko kambijeve aktivnosti in nastanka lesa pri bukvi (Fagus sylvatica L.) z rastišča Panška reka (400 m n.m.v.) in Menina planina (1200 m n.m.v.) v letu 2008. Raziskave smo opravili na tkivih lesa, kambija in skorje, odvzetih iz odraslih dreves s pomočjo metode mikro vzorčenja v tedenskih intervalih med vegetacijsko dobo. Delitve v kambiju so se na Panški reki začele prej (med 14. aprilom in 12. majem) in zaključile kasneje (med 30. junijem in 25. avgustom) kot na Menini planini (začetek med 16. in 23. majem ter zaključek med 30. junijem in 25. julijem). Najintenzivnejše celične delitve smo na obeh rastiščih zabeležili nekaj dni pred poletnim solsticijem. Na Panški reki je nastajanje lesa trajalo od 11 do 19 tednov, srednja širina branike pa je bila približno 3 mm. Na Menini planini je nastajanje lesa trajalo 6 do 7 tednov, srednja širina branike pa je bila približno 1 mm. Na Panški reki so bili tedenski prirastki lesa v povprečju skoraj trikrat večji kot na Menini planini, večja je bila tudi variabilnost med drevesi. To so potrdile tudi dendrokronološke raziskave. Primerjave lokalnih kronologij širin branik nakazujejo, da na Panški reki poletne visoke temperature in poletna suša negativno vplivajo na širine branik, na Menini planini pa vladajo visokogorske razmere, kjer imajo višje poletne temperature pozitiven vpliv na rast.We present the dynamics of cambial activity and wood formation in beech (Fagus sylvatica L.) from two sites Panška reka (400 m a.s.l.) and Menina planina (1200 m a.s.l.) in 2008. Research was conducted on the tissues of wood, cambium and bark taken from adult trees using the micro-coring technique. The cores were taken at weekly intervals during the vegetation period. Cambial divisions began at Panška reka earlier (between 14 April and 12 May) and finished later (between 30 June and 25 August) than at Menina planina (onset between 16 and 23 May, end between 30 June and 25 July). The highest cell production was recorded at both sites few days before the summer solstice. At Panška reka, the formation of tree-ring lasted 11 to 19 weeks and the mean tree-ring width was about 3 mm. At Menina planina the production of wood lasted 6 to 7 weeks, and the mean tree-ring width was 1 mm. Greater variability among trees at Panška reka was also confirmed with dendrochronological investigations. Comparisons of local tree-ring chronologies indicated that summer drought and high summer temperatures negatively affected variation of tree-ring widths at Panška reka. The situation at Menina planina corresponded to high mountain conditions where higher summer temperatures positively affect the growth

    Narcissism and the strategic pursuit of short-term mating : universal links across 11 world regions of the International Sexuality Description Project-2.

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    Previous studies have documented links between sub-clinical narcissism and the active pursuit of short-term mating strategies (e.g., unrestricted sociosexuality, marital infidelity, mate poaching). Nearly all of these investigations have relied solely on samples from Western cultures. In the current study, responses from a cross-cultural survey of 30,470 people across 53 nations spanning 11 world regions (North America, Central/South America, Northern Europe, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, Southeast Asia, and East Asia) were used to evaluate whether narcissism (as measured by the Narcissistic Personality Inventory; NPI) was universally associated with short-term mating. Results revealed narcissism scores (including two broad factors and seven traditional facets as measured by the NPI) were functionally equivalent across cultures, reliably associating with key sexual outcomes (e.g., more active pursuit of short-term mating, intimate partner violence, and sexual aggression) and sex-related personality traits (e.g., higher extraversion and openness to experience). Whereas some features of personality (e.g., subjective well-being) were universally associated with socially adaptive facets of Narcissism (e.g., self-sufficiency), most indicators of short-term mating (e.g., unrestricted sociosexuality and marital infidelity) were universally associated with the socially maladaptive facets of narcissism (e.g., exploitativeness). Discussion addresses limitations of these cross-culturally universal findings and presents suggestions for future research into revealing the precise psychological features of narcissism that facilitate the strategic pursuit of short-term mating

    Narcisismo y búsqueda estratégica del emparejamiento a corto plazo a través de las culturas: Enlaces omnipresentes a través de 11 regiones mundiales del Proyecto de la descripción de la sexualidad internacional 2

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    Previous studies have documented links between sub-clinical narcissism and the active pursuit of short-term mating strategies (e.g., unrestricted sociosexuality, marital infidelity, mate poaching). Nearly all of these investigations have relied solely on samples from Western cultures. In the current study, responses from a cross-cultural survey of 30,470 people across 53 nations spanning 11 world regions (North America, Central/South America, Northern Europe, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, Southeast Asia, and East Asia) were used to evaluate whether narcissism (as measured by the Narcissistic Personality Inventory; NPI) was universally associated with short-term mating. Results revealed narcissism scores (including two broad factors and seven traditional facets as measured by the NPI) were functionally equivalent across cultures, reliably associating with key sexual outcomes (e.g., more active pursuit of short-term mating, intimate partner violence, and sexual aggression) and sex-related personality traits (e.g., higher extraversion and openness to experience). Whereas some features of personality (e.g., subjective well-being) were universally associated with socially adaptive facets of Narcissism (e.g., self-sufficiency), most indicators of short-term mating (e.g., unrestricted sociosexuality and marital infidelity) were universally associated with the socially maladaptive facets of narcissism (e.g., exploitativeness). Discussion addresses limitations of these cross-culturally universal findings and presents suggestions for future research into revealing the precise psychological features of narcissism that facilitate the strategic pursuit of short-term mating.Estudios previos, en primer lugar a través de las muestras de culturas occidentales, han documentado asociaciones sistemáticas del narcisismo subclínico con múltiples indicadores de estrategias del emparejamiento a corto plazo (p. ej. sociosexualidad ilimitada, infidelidad, caza de pareja). En este estudio se han usado respuestas de la encuesta transcultural de 30.470 personas de 53 naciones de 11 regiones mundiales (América del Norte, América del Sur/América Central, Europa del Norte, Europa del Oeste, Europa del Este, Europa del Sur, Oriente Próximo, África, Asia del Sur/Sudoeste de Asia, Asia del Este y Oceanía) para evaluar si el narcisismo (medido por el Inventario de Personalidad Narcisista; NPI) se asocia panuniversalmente con los indicadores del emparejamiento a corto plazo, tanto en la dirección, como en la intensidad. Los resultados sugieren que el narcisismo (incluidos muchos aspectos suyos medidos por el NPI) tiene las mismas asociaciones básicas con los rasgos de personalidad relacionados con el sexo (p. ej. extraversión alta) y con los resultados sexuales claves (p. ej. búsqueda más activa de las estrategias del emparejamiento a corto plazo) a través de las 11 mayores regiones mundiales del PDSI 2. La discusión se enfoca en las implicaciones y limitaciones del estudio actual

    Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

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    Silver fir Abies alba Mill. wood as raw material and tree tissue

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    We present the structure, properties and use of European silver fir (Abies alba Mill.) wood, which is known for its uncoloured heartwood, medium density,relatively good mechanical properties and the fact that it can be used for a great variety of products. The value and usefulness of fir wood are reduced due to low resistance against decay and deterioration, and frequent occurrence of wet heart, and ring shakes. The properties of fir wood are comparable to those of Norway spruce (Picea abies Karst.). Fir is favoured where resin is not desired, where durability against acids and bases is important, and for water constructions. We present some examples of wooden constructions in archaeological or historical objects in Slovenia. The dendrochronologically dated wood was up to 500 years old. In the past centuries, fir was used more frequently than Norway spruce. On the cellular level, the wood of fir consists of tracheids and parenchyma cells. In Slovenia, several studies of wood formation have been conducted e in recent years, which are important for a better understanding of the physiology of trees and quality of wood as material. Secondary phloem, which is particularly important for the survival of trees, has been studied as well. We review some main results of such studies

    Wood identification in objects of cultural heritage

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    We present the importance of exact wood identification for the purposes of conservation and restoration. We describe the procedures used such as sampling of wood, preparation of microscopic slides, and wood identification. The results of investigations of historic woods at the wood anatomy laboratory of the Department of Wood Science and Technology, Biotechnical Faculty are presented
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