44 research outputs found
Forest stand biomass of Picea spp.: an additive model that may be related to climate and civilisational changes
Since ancient times, climate change has largely determined the fate of human civilisation, which was related mainly to changes in the structure and habitats of forest cover. In the context of current climate change, one must know the capabilities of forests to stabilise the climate by increasing biomass and carbon-depositing abilities. For this purpose, the authors compiled a database of harvest biomass (t/ha) in 900 spruce (Picea spp.) sample plots in the Eurasian area and used the methodology of multivariate regression analysis. The first attempt at modelling changes in the biomass additive component composition has been completed, according to the Trans-Eurasian hydrothermal gradients. It is found that the biomass of all components increases with the increase in the mean January temperature, regardless of mean annual precipitation. In warm zonal belts with increasing precipitation, the biomass of most of the components increases. In the process of transitioning from a warm zone to a cold one, the dependence of all biomass components upon precipitation is levelled, and at a mean January temperature of ˗30°C it becomes a weak negative trend. With an increase in temperature of 1°C in different ecoregions characterised by different values of temperature and precipitation, there is a general pattern of decrease in all biomass components. With an increase in precipitation of 100 mm in different ecoregions characterised by different values of temperature and precipitation, most of the components of biomass increase in warm zonal belts, and decrease in cold ones. The development of such models for the main forest-forming species of Eurasia will make it possible to predict changes in the productivity of the forest cover of Eurasia due to climate change
The Use of Mentored Inquiry Communities to Foster Scholarship of Teaching and Learning (SoTL): Outcomes of the American Occupational Therapy Association SoTL Program (2007-2017)
Scholarship of teaching and learning (SoTL) is recognized in Boyer’s model, along with discovery, integration, and application, as one of four essential scholarships and is the systematic study of teaching and learning. As such, in 2007, the American Occupational Therapy Foundation (AOTF), and later the American Occupational Therapy Association (AOTA), supported the development of a SoTL mentorship program in an effort to foster SoTL within the discipline of occupational therapy. This mixed-methods study describes AOTA SoTL Program outcomes across ten years, 2007-2017, gathered via survey of past program mentee (n = 50) and mentor (n = 12) participants. Results suggest that mentored inquiry communities are a useful approach to fostering SoTL collaborations. In the future, the AOTA SoTL Program and similar disciplinary-specific SoTL programs should consider additional strategies for supporting mentee participants to completion with their projects
Forest stand biomass of Picea spp.: an additive model that may be related to climate and civilisational changes
Since ancient times, climate change has largely determined the fate of human civilisation, which was related mainly to changes in the structure and habitats of forest cover. In the context of current climate change, one must know the capabilities of forests to stabilise the climate by increasing biomass and carbon-depositing abilities. For this purpose, the authors compiled a database of harvest biomass (t/ha) in 900 spruce (Picea spp.) sample plots in the Eurasian area and used the methodology of multivariate regression analysis. The first attempt at modelling changes in the biomass additive component composition has been completed, according to the Trans-Eurasian hydrothermal gradients. It is found that the biomass of all components increases with the increase in the mean January temperature, regardless of mean annual precipitation. In warm zonal belts with increasing precipitation, the biomass of most of the components increases. In the process of transitioning from a warm zone to a cold one, the dependence of all biomass components upon precipitation is levelled, and at a mean January temperature of -30 degrees C it becomes a weak negative trend. With an increase in temperature of 1 degrees C in different ecoregions characterised by different values of temperature and precipitation, there is a general pattern of decrease in all biomass components. With an increase in precipitation of 100 mm in different ecoregions characterised by different values of temperature and precipitation, most of the components of biomass increase in warm zonal belts, and decrease in cold ones. The development of such models for the main forest-forming species of Eurasia will make it possible to predict changes in the productivity of the forest cover of Eurasia due to climate change
Halophyte–Endophyte Interactions: Linking Microbiome Community Distribution and Functionality to Salinity
Many plants are unable to adapt to rapid environmental changes (e.g., salinity, drought, or limited nutrients) and may acquire assistance from microbes that have the capacity to increase tolerance of host-plants in stress conditions. By having the right microbes, the plants are more resilient! Such microbes include endophytes that inhabit inner tissues of the plant without causing symptoms of disease in their host. However, this plant–endophytic association exists only when chemical equilibrium is maintained between both, therefore making this mutualistic interaction even more unique. Therefore it is interesting to decode the endophytic community composition in halophytes specifically in the most salt-tolerant halophyte species Salicornia europaea, and further determine the factors that could affect this association. Moreover, understanding the endophytes potential plant growth-promoting activities in association with host (S. europaea) and non-host plant (non-halophytes) are the focus of this chapter
A window into fungal endophytism in Salicornia europaea: deciphering fungal characteristics as plant growth promoting agents
Aim Plant-endophytic associations exist only when equilibrium is maintained between both partners. This study analyses the properties of endophytic fungi
inhabiting a halophyte growing in high soil salinity and tests whether these fungi are beneficial or detrimental when non-host plants are inoculated.
Method Fungi were isolated from Salicornia europaea collected from two sites differing in salinization history (anthropogenic and naturally saline) and analyzed for plant growth promoting abilities and non-host plant interactions.
Results Most isolated fungi belonged to Ascomycota (96%) including dematiaceous fungi and commonly known plant pathogens and saprobes. The strains were
metabolically active for siderophores, polyamines and indole-3-acetic acid (mainly Aureobasidium sp.) with very low activity for phosphatases. Many showed proteolytic, lipolytic, chitinolytic, cellulolytic and amylolytic activities but low pectolytic activity. Different activities between similar fungal species found in both sites were particularly seen for Epiccocum sp., Arthrinium sp. and
Trichoderma sp. Inoculating the non-host Lolium perenne with selected fungi increased plant growth, mainly in the symbiont (Epichloë)-free variety.
Arthrinium gamsii CR1-9 and Stereum gausapatum ISK3-11 were most effective for plant growth promotion.
Conclusions This research suggests that host lifestyle and soil characteristics have a strong effect on endophytic fungi, and environmental stress could disturb the
plant-fungi relations. In favourable conditions, these fungi may be effective in facilitating crop production in non-cultivable saline lands
Regression models for impact of soil properties on site index class of Scots pine (Pinus sylvestris L.) stands in south-western Poland
The research was conducted in 268 pine stands on soils of sandy texture. In the paper 6 regression models for site index of Scots pine (Pinus sylvestris L.) were presented. The soil properties enclosed in the models explained to 40−60% of the site index variability. In the regression analyses, the following soil properties were found to be the best variables that described the site index: pHKCl, contents of fine textural fractions, content of K and N, CaCO3 content, soil moisture conditions reflected in gleying occurrence in a soil profile and a thickness of a solum or of a humus horizon (depending on the site moisture). The CaCO3 content was found to be a useful variable for the site index models only unless other chemical soil parameters were available. In such cases occurrence of CaCO3 in models reflects an impact of K and Mg soil content on pine growth that results from strong intercorrelations between Ca, K and Mg contents in the investigated soils. The site index was higher when pine stands were overgrowing gleyic than non−gleyic soils. In the presented regression models the difference was estimated to be about 1.5 m
XCleaner: A new method for clustering XML documents by structure
With the vastly growing data resources on the Internet, XML is one of the most important standards for document management. Not only does it provide enhancements to document exchange and storage, but it is also helpful in a variety of information retrieval tasks. Document clustering is one of the most interesting research areas that utilize semi-structural nature of XML. In this paper, we put forward a new XML clustering algorithm that relies solely on document structure. We propose the use of maximal frequent subtrees and an operator called Satisf/Violate to divide documents into groups. The algorithm is experimentally evaluated on real and synthetic data sets with promising results
Szacowanie parametrów wytrzymałościowych wyrobów lotniczych z kompozytów polimerowych z kompozytów polimerowych z uwzględnieniem teorii łańcuchów Markowa
The study investigates the fatigue strength of a component made of a glass composite material with polyester matrix, manufactured using a contact method (I) and by vacuum bagging (II). Modeling was carried out only for composite material II, due to significant spread of the strength of the composite material manufactured by contact lamination I, which means that such a material does not guarantee repeatability of the test results. Estimation of the composite material fatigue
strength and residual strength was performed using a mathematical model based on the Markov chain theory. The model assumed that the material failure occurs at certain critical microvolume of the components operating within the
plastic range. Observed relationships between the probability values and the distribution parameters for the tatic strength of the composite components, as well as the load values allow for
deriving a fatigue curve equation. Obtained results are presented in the tables.W pracy zbadano wytrzymałość zmęczeniową kompozytu szklanego o osnowie poliestrowej, wytworzonego metodą kontaktową (I) i metodą worka próżniowego (II). Modelowanie przeprowadzono tylko dla kompozytu II, ze względu na znaczny rozrzut wytrzymałości kompozytu wykonanego metodą laminowania kontaktowego I, co oznacza kompozyt ten nie daje gwarancji powtarzalności wyników badania. Do szacowania wytrzymałości zmęczeniowej i wytrzymałości
resztkowej kompozytów zastosowano model matematyczny bazujący na teorii łańcuchów Markowa. W modelu założono, iż zniszczenie materiału zachodzi przy pewnej krytycznej mikroobjętości komponentów pracujących w zakresie sprężystym. Zaobserwowane związki prawdopodobieństw
z parametrami rozkładu wytrzymałości statycznej komponentów kompozytów i wielkości obciążeń pozwalają otrzymać równanie krzywej zmęczeniowej. Uzyskane wyniki badań zestawiono
w tabelach