Enhancing fauna habitat in grazed native grasslands and woodlands: use of artificially placed log refuges by fauna

2004 ◽  
Vol 31 (1) ◽  
pp. 65 ◽  
Author(s):  
Damian R. Michael ◽  
Ian D. Lunt ◽  
Wayne A. Robinson
Keyword(s):  
Native Species ◽  
Habitat Restoration ◽  
Structural Characteristics ◽  
Survey Method ◽  
Potential Habitat ◽  
Native Grasslands ◽  
Restoration Technique ◽  
Arid Grasslands ◽  
Different Characteristics

To assess whether faunal habitat can be enhanced by using artificial refuges, and whether different species preferentially use refuges with differing structural characteristics, we monitored faunal usage of artificially placed log refuges in grazed semi-arid grasslands and woodlands in Terrick Terrick National Park in Victoria. In total, 1131 log refuges were placed at 91 sites across major vegetation types in the reserve. The effect of refuge age was assessed by comparing faunal usage between new refuges and 271 old refuges that had lain in situ for more than 15 years. Refuges were surveyed for fauna monthly between June 2000 and January 2001. Different species preferred refuges with different characteristics. Overall terrestrial fauna, and three native species (Diplodactylus tessellatus, Morethia boulengeri and Suta suta) in particular, were significantly more abundant beneath old refuges, whereas the introduced Mus musculus was significantly more abundant beneath new refuges. Five species (Crinia signifera, Morethia boulengeri, Menetia greyii, Sminthopsis crassicaudata and Suta suta) were significantly more abundant beneath Eucalyptus logs that were large, wide, partially decayed, contained many holes and/or covered many subterranean invertebrate holes. This study demonstrates the effectiveness of installing log refuges in grassy landscapes as a survey method for vertebrate fauna and as a potential habitat-restoration technique to help conserve grassland fauna.

A study on the kinetics and thermal properties of polystyrene/diatomite nanocomposites prepared via in situ ATRP

2018 ◽  
Vol 33 (2) ◽  
pp. 180-197 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Molecular Weight ◽  
In Situ Polymerization ◽  
Structural Characteristics ◽  
Nitrogen Adsorption ◽  
Linear Increase ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Exclusion Chromatography

Pristine mesoporous diatomite was employed to prepare polystyrene/diatomite composites. Diatomite platelets were used for in situ polymerization of styrene by atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. X-Ray fluorescence spectrometer analysis and thermogravimetric analysis (TGA) were employed for evaluating some inherent properties of pristine diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Linear increase of ln ( M0/M) with time for all the samples shows that polymerization proceeds in a living manner. Addition of 3 wt% pristine mesoporous diatomite leads to an increase of conversion from 72% to 89%. Molecular weight of polystyrene chains increases from 11,326 g mol−1 to 14134 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.13 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 81.9°C to 87.1°C by adding 3 wt% of mesoporous diatomite platelets.

scholarly journals VERIFICAÇÃO DO DESEMPENHO DAS ESTACAS INJETADAS AUTOPERFURANTES EXECUTADAS EM SOLOS ARENOSOS PARA CONSTRUÇÃO DE USINA EÓLICA

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Rodrigo Cerqueira Rogerio
Keyword(s):  
Structural Characteristics ◽  
Load Capacity ◽  
The Self ◽  
Executive Processes ◽  
Empirical Methods ◽  
Deep Drilling ◽  
Load Tests ◽  
Different Diameters ◽  
Semi Empirical

RESUMO: Apresenta-se neste trabalho a solução adotada para execução das fundações do Parque de Usina Eólica localizado no Ceará, com a utilização das estacas injetadas autoperfurantes, executadas em presença de solos arenosos. No qual consiste em perfurar o solo com altíssima velocidade por rotação e “pull down”, através da injeção simultânea de nata de cimento com medias pressões. Ocasionando na estaca um diâmetro final que pode obter o dobro do bit de perfuração, de acordo com o tipo de solo, gerado pelo efeito do jato da nata de cimento. Detalhando os processos executivos, verificando os aspectos técnicos e operacionais, para melhor compreender as características estruturais deste elemento. De forma a verificar “in situ” o desempenho deste novo tipo de fundação profunda, foram realizadas provas de carga, em estacas com diferentes diâmetros e comprimentos, realizadas em perfis estratigráficos de solos arenosos, para melhor avaliação de sua capacidade de carga. Analisando-se os ensaios das provas de carga interpretados a base da extrapolação da curva carga versus recalque e das previsões da capacidade de carga, obtidas por meio dos métodos semi-empíricos de correlação com ensaios de penetração (SPT), avaliando os padrões de execução desta tipologia de estaca injetada para comunidade geotécnica. ABSTRACT: This paper aims to establish the selected solution to except the foundations of the Wind Energy Park in Ceará (Brazil), with an executive methodology of the self-drilling injection piles framed in loco in Sandy soil. In which the soil drilling is done with the highest speed by rotation and pull down, through the simultaneous injection of grouting with medium pressures. This kind of drilling causes in the pile a final diameter that can get the double bore bit, according to the type of soil, done by the grouting blast. The executive processes are detailed as a whole, and also presenting the pile materials composition, in order to understand the structural characteristics of this element. To verify the performance of this new kind of deep drilling, instrumentations were done: settlement control and load tests in constructions with different structural characteristics, in self-drilling injected piles with different diameters and length, done in stratigraphical sandy, for a better evaluation of its load capacity. Analyzing the essays of load tests interpreted in the basis of curve extrapolation load versus settlement and the previsions of the load capacity, obtained by semi-empirical methods correlating with the penetrations methods (SPT), offering information to the geotechnical community.

scholarly journals Graphene Oxide-Embedded Extracellular Matrix- Derived Hydrogel as a Multiresponsive Platform for 3D Bioprinting Applications

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Laura Rueda-Gensini ◽  
Julian A Serna ◽  
Javier Cifuentes ◽  
Juan C Cruz ◽  
Carolina Muñoz-Camargo
Keyword(s):  
Graphene Oxide ◽  
Mechanical Stability ◽  
Light Exposure ◽  
Structural Characteristics ◽  
Elastic Response ◽  
Cellular Interaction ◽  
3D Bioprinting ◽  
In Situ Reduction ◽  
Crosslinking Degree

Decellularized extracellular matrices (dECMs) have shown enormous potential for the biofabrication of tissues due to their biomimetic properties that promote enhanced cellular interaction and tissue regeneration. However, biofabrication schemes requiring electrostimulation pose an additional constraint due to the insulating properties of natural materials. Here, we propose a methacryloyl-modified decellularized small intestine submucosa (SISMA) hydrogel, embedded with graphene oxide (GO) nanosheets, for extrusion-based 3D bioprinting applications that require electrostimulation. Methacryloyl biochemicalmodification is performed to enhance the mechanical stability of dECM constructs by mediating photo-crosslinking reactions, and a multistep fabrication scheme is proposed to harness the bioactive and hydrophilic properties of GO and electroconductive properties of reduced GO. For this, GO was initially dispersed in SISMA hydrogels by exploiting its hydrophilicity and protein adsorption capabilities, and in situ reduction was subsequently performed to confer electroconductive abilities. SISMA-GO composite hydrogels were successfully prepared with enhanced structural characteristics, as shown by the higher crosslinking degree and increased elastic response upon blue-light exposure. Moreover, GO was homogeneously dispersed without affecting photocrosslinking reactions and hydrogel shear-thinning properties. Human adipose-derived mesenchymal stem cells were successfully bioprinted in SISMA-GO with high cell viability after 1 week and in situ reduction of GO during this period enhanced the electrical conductivity of these nanostructures. This work demonstrates the potential of SISMA-GO bioinks as bioactive and electroconductive scaffolds for electrostimulation applications in tissue engineering and regenerative medicine.

scholarly journals Analysis of Gastropod Diversity as a Bioindicator of Waters in Situ Ciburuy Padalarang, West Bandung Regency, West Java, Indonesia

2021 ◽  
pp. 10-19
Author(s):  
Erwin Theofilius ◽  
Zahidah Hasan ◽  
Asep Agus Handaka ◽  
Herman Hamndani
Keyword(s):  
Water Quality ◽  
Species Diversity ◽  
Sampling Method ◽  
Diversity Index ◽  
Research Area ◽  
Survey Method ◽  
Gastropod Species ◽  
Evenness Index

This study conducted to determine the water quality of Situ Ciburuy based on the structure of the gastropod community as a bioindicator. The survey method used in this study based on collecting data directly at the research area (purpose sampling method).  For instance, species and density of gastropods were descriptively analyzed, using diversity index and evenes index. For instance, The findings showed that level of water quality in  Situ Ciburuy based on gastropods bioindicators was lightly polluted. That is indicated by the low to moderate diversity of gastropods, which ranges from 1.31-1.98. The Shannon evenness index (0,73-0.95) revealed low gastropod species diversity in Situ Ciburuy, indicating low evenness of gastropod in Situ Ciburuy.

scholarly journals Feeding ground indications are based on species, seagrass density and existence of Dugong dugon in Hiri Island Sea, North Maluku, Indonesia

2021 ◽  
Vol 890 (1) ◽  
pp. 012058
Author(s):  
N Akbar ◽  
I Marus ◽  
R Ridwan ◽  
A Baksir ◽  
R E Paembonan ◽  
...  
Keyword(s):  
Species Conservation ◽  
Species Density ◽  
Survey Method ◽  
Conservation Policies ◽  
Potential Habitat ◽  
Foraging Area ◽  
Seagrass Ecosystem ◽  
Seagrass Ecosystems ◽  
Halodule Uninervis ◽  
Management And Conservation

Abstract Seagrass ecosystems are located between mangrove ecosystems and coral reefs. Seagrass ecosystems are habitats and foraging area for many marine organisms. Eco-biological cycles in seagrass ecosystems are important for maintaining populations of many organisms. Seagrass at Hiri Island is distributed horizontally along the coast. This island is also a location where Dugong dugon is found North Maluku. Dugong dugon is a vurneable species that has been included in the IUCN and Appendix I Cites. This study aimed to identify species, density of seagrass and existence of Dugong dugong. The survey method used quadratic transect method to collect seagrass data. The Results found 6 species of seagrass at Hiri Island. Five species of those seagrass (Cymodocea serrulata, Cymodecea rotundata, Halodule uninervis, Halodule pinifolia, Halophila spinulosa) are known as food of Dugong dugon. The highest species density was shown by Halodule uninervis. The presence of Dugong dugon and its feeding trail was found during field survey. Information on seagrass species and Dugong dugon sightings location can be used for endangered species conservation policies. Management and conservation efforts need to be done to maintain seagrass ecosystem and Dugong dugon potential habitat at Hiri Island.

Street-Level Imagery and Deep Learning for Characterization of Exposed Buildings

2021 ◽  
Author(s):  
Patrick Aravena Pelizari ◽  
Christian Geiß ◽  
Elisabeth Schoepfer ◽  
Torsten Riedlinger ◽  
Paula Aguirre ◽  
...  
Keyword(s):  
Deep Learning ◽  
Structural Characteristics ◽  
High Accuracy ◽  
Risk Modeling ◽  
Sources Of Information ◽  
Large Area ◽  
Image Domain ◽  
Street Level ◽  
Building Characteristics

<p>Knowledge on the key structural characteristics of exposed buildings is crucial for accurate risk modeling with regard to natural hazards. In risk assessment this information is used to interlink exposed buildings with specific representative vulnerability models and is thus a prerequisite to implement sound risk models. The acquisition of such data by conventional building surveys is usually highly expensive in terms of labor, time, and money. Institutional data bases such as census or tax assessor data provide alternative sources of information. Such data, however, are often inappropriate, out-of-date, or not available. Today, the large-area availability of systematically collected street-level data due to global initiatives such as Google Street View, among others, offers new possibilities for the collection of <em>in-situ</em> data. At the same time, developments in machine learning and computer vision – in deep learning in particular – show high accuracy in solving perceptual tasks in the image domain. Thereon, we explore the potential of an automatized and thus efficient collection of vulnerability related building characteristics. To this end, we elaborated a workflow where the inference of building characteristics (e.g., the seismic building structural type, the material of the lateral load resisting system or the building height) from geotagged street-level imagery is tasked to a custom-trained Deep Convolutional Neural Network. The approach is applied and evaluated for the earthquake-prone Chilean capital Santiago de Chile. Experimental results are presented and show high accuracy in the derivation of addressed target variables. This emphasizes the potential of the proposed methodology to contribute to large-area collection of <em>in-situ</em> information on exposed buildings.</p>

The effect of increased ground-level habitat complexity on mouse population dynamics

2003 ◽  
Vol 30 (6) ◽  
pp. 565 ◽  
Author(s):  
A. D. Arthur ◽  
R. P. Pech ◽  
A. Drew ◽  
E. Gifford ◽  
S. Henry ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Native Species ◽  
Habitat Complexity ◽  
Habitat Structure ◽  
Ground Level ◽  
Low Complexity ◽  
Mouse Population ◽  
Introduced Predators ◽  
The Impact

We investigated experimentally the influence of habitat structure on the population dynamics of house mice. Three habitat types were used. In one, dense stands of regenerating cypress pine were felled and left in situ to cover at least 40% of experimental plots, providing high complexity at ground level; in another, dense stands of regenerating pine were left intact, providing low complexity at ground level; in the third, open grassland adjacent to dense stands of regenerating pine also provided low complexity at ground level. Mouse populations occurred at higher densities in felled pine plots compared with both the standing pine and grassland plots, consistent with the hypothesis that the presence of increased habitat complexity at ground level reduced the impact of predation. Even though populations responded to the felled pine, they dropped to very low densities over winter, suggesting that the habitat was still marginal for the persistence of mice, probably due to a lack of food. The results are discussed with reference to their implications for the influence that habitat structure may have on the impact of introduced predators on native species.

scholarly journals Native Seedling Colonization on Stockpiled Mine Soils Is Constrained by Site Conditions and Competition with Exotic Species

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 361 ◽  
Author(s):  
Kathy A. Baethke ◽  
Laura W. Ploughe ◽  
Wendy C. Gardner ◽  
Lauchlan H. Fraser
Keyword(s):  
Exotic Species ◽  
Seedling Establishment ◽  
Native Species ◽  
Seed Treatment ◽  
Native Vegetation ◽  
Mine Soils ◽  
Native Seed ◽  
Restoration Strategies ◽  
Arid Grasslands ◽  
Establishment Phase

Sites disturbed through mining practices can be challenging to restore with native vegetation, as the path of ecological succession is often unknown and hard to predict. We conducted an establishment study that explored restoration strategies to increase native vegetation on a newly formed stockpile of soil at New Gold’s New Afton Mine in British Columbia, Canada. Establishment of native species in semi-arid grasslands is often constrained by seed and seedling microsite limitations, so treatments were imposed to assist in reducing these limitations. We established a fully factorial design with a native seed treatment (seeded and unseeded) and four soil preparations: raking, hydroseed slurry, a combination of raking and hydroseed slurry, and no preparation. Raking assisted in increasing total seedling establishment, regardless of whether the site was seeded or not. Raking and seeding increased the number of native seedlings and resulted in the greatest species richness, suggesting that native seedling establishment is primarily seed-limited, but that microclimate is also important for the establishment of some native seeds. We found that exotic species were able to capitalize on the disturbance and outcompeted the native species, but reducing seed-limitations by sowing more native seeds and increasing available microclimates by raking or tilling may increase native species’ success at the establishment phase.

Terrestrial laser scanning and structure-from-motion photogrammetry concordance analysis for describing the surface layer of gravel beds

2019 ◽  
Vol 43 (2) ◽  
pp. 260-281 ◽  
Author(s):  
Andrew J Neverman ◽  
Ian C Fuller ◽  
Jon N Procter ◽  
Russell G Death
Keyword(s):  
Surface Layer ◽  
Structure From Motion ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Survey Method ◽  
Gravel Beds ◽  
Non Invasive ◽  
Sampling Biases

Terrestrial laser scanning (TLS) and structure-from-motion photogrammetry (SfMp) offer rapid, non-invasive surveying of in situ gravels. Numerous studies have used the point clouds derived from TLS or SfMp to quantify surface layer characteristics, but direct comparison of the methods for grain-scale analysis has received relatively little attention to date. Comparing equivalent products of different data capture methods is critical as differences in errors and sampling biases between the two methods may produce different outputs, effecting further analysis. The sampling biases and errors related to SfMp and TLS lead to differences in the point clouds produced by each method. The metrics derived from the point clouds are therefore likely to differ, potentially leading to different inputs for entrainment threshold models, different trends in surface layer development being identified and different trajectories for physical processes and habitat quality being predicted. This paper provides a direct comparison between TLS and SfMp surveys of an exposed gravel bar for three different survey periods following inundation and reworking of the bar surface during high flow events. The point clouds derived from the two methods are used to describe changes in the character of the surface layer between bar inundation events, and comparisons are made with descriptions derived from conventional pebble counts. The results found differences in the metrics derived using each method do exist, but the grid resolution used to detrend the surfaces and identify spatial variations in surface layer characteristics had a greater impact than survey method. Further research is required to understand the significance of these variations for quantifying surface texture and structure and for predicting entrainment thresholds and transport rates.

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