9 research outputs found
MD Dating – Dating of wood based on its molecular decay (MD) measured using FTIR spectroscopy
The canine counts! Significance of a craniodental measure to describe sexual dimorphism in canids : Golden jackals (Canis aureus) and African wolves (Canis lupaster)
Sexual dimorphism is a widespread phenomenon among mammals, including carnivorans. While sexual dimorphism in golden jackals (Canis aureus) has been analysed in the past, in the related and apparently convergent canid, the African wolf (Canis lupaster), it is poorly studied and showed to be relatively small. Previously, sexual size dimorphism (SSD) research in these species was mostly based on skull and body measurements. In our study, we also included dental measurements, namely the diameter of the canine. We used 11 measured sections of 104 adult specimens, comprising 61 golden jackal and 43 African wolf skulls. Data analyses were carried out through logistic regression and conditional inference trees (CIT). To compare the results of SSD to other species, sexual dimorphism indices (SDI) were calculated. Golden jackals and African wolves show significant sexual size dimorphism, both in cranial and dental size. The logistic regression revealed that the mesiodistal diameter of the upper canine is most effective in discerning the sexes. The difference in the calculated SDI of the canine diameter between the sexes amounted to 8.71 in golden jackals and 14.11 in African wolves, respectively-with regional diversity. Thus, the canine diameter is an important measure to investigate SSD as well as an easy tool to apply in the field.Peer reviewe
Plant succession research on disturbed sites as a tool for bioindication
Die vorliegende Dissertation befasst sich mit den Möglichkeiten vegetationsökologischer Methoden für die Ingenieursarbeit an gestörten Sonderstandorten. Diese Standorte bedürfen einer besonderen Planung, da im Allgemeinen entweder potentielle Gefahren von ihnen ausgehen, oder die Störungen eine normale Nutzung dieser Flächen unmöglich oder zumindest sehr schwierig machen. Beim Beispiel Deponieflächen wird gezeigt, dass Substrateigenschaften der Deponieabdeckung und Emissionssituation mit Hilfe der Spontanvegetation beschrieben werden können. Dadurch kann der Nachsorgezeitraum von alten Deponien effizient bestimmt bzw. überprüft werden. Gerade bei den Emissionen sind die Ergebnisse der Vegetationsökologie den klassisch angewandten, chemisch-physikalischen Analysemethoden an Aussagekraft überlegen. An einem Fallbeispiel einer Deponie im Mürztal (Steiermark) wird die Anwendbarkeit der Methoden zur Emissionsbeurteilung bewiesen. Das zweite Störungsbeispiel stellen Hochwasserbegleitflächen dar. Durch eine 10 Jahre lange Datenreihe wird die Sukzession an ausgewählten Flächen nach dem Jahrhundertereignis 2002 im Kamptal (Niederösterreich) dokumentiert. Veränderungen der Körngröße, im Nährstoffangebot der Flächen und der wachsende Konkurrenzdruck innerhalb der Vegetation können überwacht werden. Das dritte diskutierte Beispiel ist eine geologische Massenbewegung des Jahres 1999 im vorderen Bregenzerwald (Vorarlberg). Die Vegetation eines Teiles des betroffenen Hanges wurde fünf bzw. 13 Jahre später erhoben. Pflanzen zeigen nicht nur den allgemeinen Zustand des Substrates, insbesondere das geologische Material des Untergrundes, sondern auch relativ kleine Unterschiede, die sich z.B. im Basengehalt des Bodens niederschlagen, können exakt aufgezeigt werden. Die Arbeit beweist die große Bedeutung der Vegetationsökologie in Ingenieursfragen und eröffnet konkrete Anwendungsmöglichkeiten, die kostensparend und effizient eingesetzt werden können.This thesis focuses on the possibilities of vegetation ecological methods for engineering at disturbed sites. These sites need special planning as they either bear potential risks or the disturbances disable or at least complicate any conventional land use on the sites. The first example deals with landfill sites. Substrate conditions of the landfill cover material and the emission situation can be described via spontaneous vegetation. Based on this information the duration of the aftercare maintenance of old landfills can be estimated in an efficient way. The monitoring of the aftercare phase can be realized by vegetation ecological methods as well. Especially emission control can be done more easily and efficiently by means of spontaneous vegetation compared to classical chemical-physical analyses. The feasibility of the methods to assess the landfill emissions was exemplified at a landfill in the Mürz valley (Styria). The second example comprises flood plain areas. Data from 10 years after a flood in the valley of the river Kamp (Lower Austria) were evaluated. Vegetation ecological methods displayed changes in the particle size composition of the substrates, changes in nutrient supply and the increasing concurrence within the vegetation. Again maintenance and after use plans could be adapted more properly and site specific using such information. The third example is a case study from the Bregenzerwald (Vorarlberg). A geological mass movement had taken place in 1999. The vegetation of a part of the affected area was assessed 5 and 13 years after the movement. The plants displayed the general substrate consistence especially the geological underground material. The thesis proves in all the cases the high potential of vegetation ecology as a helpful tool for engineers. Specific practical questions are presented, where these methods could help to improve engineering in an efficient and comparably cheap way.Johannes TintnerAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheWien, Univ. für Bodenkultur, Diss., 2013OeBB(VLID)193107
Molecular Recalcitrance of Hair Passing the Digestive System of a Canid
Hair is an important component in scat that is commonly used for prey analyses in carnivores. Chemically, hair predominately consists of keratin. The recalcitrant fiber protein is degraded in nature only by a few insects and soil microorganisms. Common proteases such as pepsin do not decompose keratin. Infrared spectroscopy was used to detect chemical differences caused by pretreatment and fate of hairs. Three sample sets were compared: original untreated hair, original milled hair, and hairs extracted from scats of golden jackals (Canis aureus L.). The results revealed that only milling affected the infrared spectral pattern, whereas digestion had no impact. Moreover, hairs from different species (e.g., boar) could be distinguished due to their spectral characteristics. They did not change through the passage of the digestive system
The potential of Mid-Infrared spectroscopy for prediction of wood density and vulnerability to embolism in woody angiosperms
Xylem resistance to embolism formation determines the species-specific drought tolerance and the survival prospects of plants under extreme climatic conditions. Fourier Transform-Infrared (FTIR) spectroscopy is a cost-effective and rapid analytical tool with potential beyond its current use in plant physiology. We tested the use of FTIR spectroscopy as a method for estimating wood density (WD) and xylem resistance to embolism formation (P50) in 24 angiosperm species. Higher WD was associated with more negative P50 (r2 = 0.41). Partial least squares regression was applied to establish models of FTIR spectra and the reference data. They showed a high predictive quality for WD (r2 = 0.73), whereas the prediction of P50 was weaker (r2 = 0.49). By including WD in the model as an additional factor influencing P50, its predictive power significantly increased (r2 = 0.59). The spectral range in the model elaboration has been also narrowed (bands of lignin, cellulose, hemicellulose), but this did not influence the model descriptors, suggesting that for P50 prediction broad spectral range is more informative than narrow band regions reflecting main wood constituents. In conclusion, FTIR spectroscopy associated with WD measurements has proven to be a promising alternative to traditional methods for screening of individual- or species-specific resistance to embolism in angiosperms
Straw in Clay Bricks and Plasters—Can We Use Its Molecular Decay for Dating Purposes?
Dating of clay bricks (adobe) and plasters is a relevant topic not only for building historians in the Pannonian region. Especially in vernacular architecture in this region, clay with straw amendments is a dominant construction material. The paper presents the potential of the molecular decay of these amendments to establish prediction tools for age based on infrared spectroscopic measurements. Preliminary results revealed spectral differences between the different plant parts, especially culms, nodes, and ear spindles. Based on these results, a first prediction model is presented including 14 historic samples. The coefficient of determination for the validation reached 62.2%, the (RMSE) root mean squared error amounted to 93 years. Taking the limited sample amount and the high material heterogeneity into account, this result can be seen as a promising output. Accordingly, sample size should be increased to a minimum of 100 objects and separate models for the different plant parts should be established