Fuel characteristics and fire behaviour in mature Mediterranean gorse shrublands

2004 ◽  
Vol 13 (1) ◽  
pp. 79 ◽  
Author(s):  
Martín De Luis ◽  
Manuel J. Baeza ◽  
José Raventós ◽  
José C. González-Hidalgo
Keyword(s):  
Forest Fires ◽  
Plant Density ◽  
Structural Characteristics ◽  
Fire Severity ◽  
Fire Behaviour ◽  
Fuel Distribution ◽  
Degree Of Dominance ◽  
Mediterranean Regions ◽  
The Relationship

Since the early 1990s, Mediterranean gorse shrublands have expanded significantly in the Mediterranean regions of Spain mainly as a result of the increase in the frequency and extension of forest fires. Mediterranean gorse (Ulex parviflorus), which has been described as a degradation stage of forest communities after fire, has also been described as a fire-prone community. Thus, its presence increases the risk that new fires might occur. In spite of this evidence, there is little information on both the composition and structural characteristics of these communities or the relationship that might exist between these vegetation characteristics and fire behaviour. In this paper we present the results of a characterization of the vegetative structure (plant density, specific composition, biomass fractions, and horizontal and vertical fuel distribution) in Mediterranean gorse. We also analyse fire behaviour using indicators obtained at different scales. Our results show mature Mediterranean gorse shrublands to be communities with high biomass values (3000–4000 g m−2) and high horizontal and vertical vegetation continuity, in which the proportion of fine dead fuel fractions with low moisture content is around 50% of the total phytomass present. Ulex parviflorus is the dominant species and its degree of dominance is a key element in the behaviour of fire. Both the fire-line intensity values and the fire severity values observed can be considered high with respect to those observed in other Mediterranean communities, thus confirming Mediterranean gorse as a high-risk community.

scholarly journals Characterization of 67 Confirmed Clustered Regularly Interspaced Short Palindromic Repeats Loci in 52 Strains of Staphylococci

2021 ◽  
Vol 12 ◽  
Author(s):  
Ying Wang ◽  
Tingting Mao ◽  
Yinxia Li ◽  
Wenwei Xiao ◽  
Xuan Liang ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Direct Repeat ◽  
Minimum Free Energy ◽  
Important Species ◽  
Crispr Locus ◽  
Adaptive Immune ◽  
Associated Proteins ◽  
The Relationship ◽  
Cas Proteins

Staphylococcus aureus (S. aureus), which is one of the most important species of Staphylococci, poses a great threat to public health. Clustered regularly interspaced short palindromic repeats (CRISPR) and their CRISPR-associated proteins (Cas) are an adaptive immune platform to combat foreign mobile genetic elements (MGEs) such as plasmids and phages. The aim of this study is to describe the distribution and structure of CRISPR-Cas system in S. aureus, and to explore the relationship between CRISPR and horizontal gene transfer (HGT). Here, we analyzed 67 confirmed CRISPR loci and 15 companion Cas proteins in 52 strains of Staphylococci with bioinformatics methods. Comparing with the orphan CRISPR loci in Staphylococci, the strains harboring complete CRISPR-Cas systems contained multiple CRISPR loci, direct repeat sequences (DR) forming stable RNA secondary structures with lower minimum free energy (MFE), and variable spacers with detectable protospacers. In S. aureus, unlike the orphan CRISPRs away from Staphylococcal cassette chromosome mec (SCCmec), the complete CRISPR-Cas systems were in J1 region of SCCmec. In addition, we found a conserved motif 5′-TTCTCGT-3′ that may protect their downstream sequences from DNA interference. In general, orphan CRISPR locus in S. aureus differed greatly from the structural characteristics of the CRISPR-Cas system. Collectively, our results provided new insight into the diversity and characterization of the CRISPR-Cas system in S. aureus.

Structural Characterization of Micron-scaled Reticulated Copper Foams

2011 ◽  
Vol 1304 ◽  
Author(s):  
Stephanie J Lin ◽  
Jason H. Nadler
Keyword(s):  
Image Analysis ◽  
Structural Characteristics ◽  
Porous Network ◽  
Unique Challenge ◽  
Copper Foam ◽  
Fluid Permeability ◽  
Capillary Fluid ◽  
Relationship Of ◽  
The Relationship

AbstractThe development of a multifunctional, micron-scaled, reticulated copper foam that reliably exhibits high intrinsic thermal conductivity, efficient capillary fluid and evaporative transport over a wide area presents a unique challenge. In this work, the relationship of critical foam processing variables such as sintering temperature and template size on the pore size distribution and pore neck/body ratio is investigated using image analysis. The resulting fluid permeability values of these foams are estimated by using the Kozeny Carman equation and the porosity, surface area per unit area and tortuosity obtained through image analysis. Estimating the fluid permeability of these foams is useful for predicting the mass and heat transfer within the porous network, and provides a metric for optimizing the foam’s structural characteristics for a particular application.

Assessment of the relationship between pre-fire fuel estimates and Fire Radiative Power in Portugal

2020 ◽  
Author(s):  
Catarina Alonso ◽  
Célia M. Gouveia ◽  
Patrícia Páscoa
Keyword(s):  
Forest Fires ◽  
Land Surface ◽  
Fire Severity ◽  
Radiative Energy ◽  
Fuel Load ◽  
Biomass Combustion ◽  
Fuel Loads ◽  
Radiative Power ◽  
The Relationship ◽  
Fire Radiative Power

<p>Forest fires are recurrent in Portugal, either due to climate conditions, to land use change, or to a combination of both. Wet and mild winters, together with dry and warm summers, favour the growth of vegetation and its subsequent low moisture content, increasing fuel availability. The assessment and management of fuel loads is essential to understand and minimize fire risk. The structural risk depends on the type of available fuel and on the age of vegetation. Therefore, reducing fuel loads is often required to mitigate fire severity.  </p><p>Active fire observations of fire radiative power (FRP) have been shown to be correlated to rates of biomass combustion. The Meteosat FRP-PIXEL product is delivered in near real-time by the EUMETSAT Land Surface Analysis Satellite Applications Facility (LSA SAF), since 2004 with 15-min temporal resolution. We propose to do the first assessment, for Portugal, of the relationship between Fire Radiative Energy (FRE) per fire and pre-fire fuel load estimates, as obtained from Dry Matter Productivity (DMP), disseminated by Copernicus Global Land Service (CGLS) at 1km spatial resolution since 1999. The analysis is performed for the main land cover types in Portugal that show high sensitivity to wildfires. The severest wildfire events in Portugal since 2004 are also analysed with detail, namely the fires of 2005, 2012 and 2017 and the obtained results related with soil moisture, fuel type and fire size.</p><p>Acknowledgements: This study was performed within the framework of the LSA-SAF, co-funded by EUMETSAT This work was partially supported by national funds through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under projects FIRECAST (PCIF/GRF/0204/2017) and IMPECAF (PTDC/CTA-CLI/28902/2017).</p>

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

Characterization of Auditory Disability and Its Relation to the Resilience

2018 ◽  
Vol 5 (2) ◽  
pp. 15
Author(s):  
Bibian Bibeca Bumbila García ◽  
Hernán Andrés Cedeño Cedeño ◽  
Tatiana Moreira Chica ◽  
Yaritza Rossana Parrales Ríos
Keyword(s):  
Social Integration ◽  
Conceptual Analysis ◽  
Disabled People ◽  
Disabled Students ◽  
Hearing Disability ◽  
Technical University ◽  
The Relationship ◽  
Made In

The objective of the work is to establish the characterization of the auditory disability and its relationship with resilience at the Technical University of Manabí. The article shows a conceptual analysis related to the inclusion and social integration of disabled students. Based on the fact that the person with disabilities grows and develops in the same way as that of people without disabilities and what usually happens is that disabled people are rejected and discriminated against based on a prefabricated and erroneous conceptualization of these people. The results associated with the application of the SV-RES test prepared by the researchers are shown (Saavedra & Villalta, 2008b). Characterization of the auditory deficit is made in the students, and the limitations that derive from it are pointed out. We analyze the particularities related to communication with students who have a hearing disability and resilience in this type of student, where some personal highlights that in this sense constitute an example of resilience. Finally, the results related to the study of the relationship between students' hearing disability and the level of resilience dimensions are shown.

The Problem of Divine Hiddenness

2018 ◽  
Author(s):  
Michael C. Rea
Keyword(s):  
Problem Of Evil ◽  
Philosophical Discussion ◽  
Detailed Characterization ◽  
The Past ◽  
Divine Hiddenness ◽  
The Problem Of Evil ◽  
The Relationship

This chapter provides a detailed characterization of the various meanings of the term “divine hiddenness,” carefully and rigorously articulates the version of the problem of divine hiddenness that has dominated contemporary philosophical discussion for the past twenty-five years, and then explains the relationship between that problem and the problem of evil.

scholarly journals Optimizing Grain Yield and Water Use Efficiency Based on the Relationship between Leaf Area Index and Evapotranspiration

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Leaf Area Index ◽  
Water Use ◽  
Plant Density ◽  
Maize Yield ◽  
Area Index ◽  
Irrigation Level ◽  
Use Efficiency ◽  
The Relationship

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.

scholarly journals Crowdsourcing and open innovation: a systematic literature review, an integrated framework and a research agenda

2021 ◽  
Author(s):  
Livio Cricelli ◽  
Michele Grimaldi ◽  
Silvia Vermicelli
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Open Innovation ◽  
Innovation Management ◽  
Academic Research ◽  
Future Research ◽  
Four Dimensions ◽  
Word Analysis ◽  
The Relationship

AbstractIn recent years, Open Innovation (OI) and crowdsourcing have been very popular topics in the innovation management literature, attracting significant interest and attention, and inspiring a rich production of publications. Although these two topics share common themes and address similar managerial challenges, to the best of our knowledge, there is no systematic literature review that digs deep into the intersection of both fields. To fill in this gap a joint review of crowdsourcing and OI topics is both timely and of interest. Therefore, the main objective of this study is to carry out a comprehensive, systematic, and objective review of academic research to help shed light on the relationship between OI and crowdsourcing. For this purpose, we reviewed the literature published on these two topics between 2008 and 2019, applying two bibliometric techniques, co-citation and co-word analysis. We obtained the following results: (i) we provide a qualitative analysis of the emerging and trending themes, (ii) we discuss a characterization of the intersection between OI and crowdsourcing, identifying four dimensions (strategic, managerial, behavioral, and technological), (iii) we present a schematic reconceptualization of the thematic clusters, proposing an integrated view. We conclude by suggesting promising opportunities for future research.

scholarly journals Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 136
Author(s):  
Bimalendu Ray ◽  
Martin Schütz ◽  
Shuvam Mukherjee ◽  
Subrata Jana ◽  
Sayani Ray ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Antiviral Drug ◽  
Natural Source ◽  
Target Interaction ◽  
Charge Densities ◽  
Linkage Pattern ◽  
Naturally Occurring ◽  
Antiviral Activities ◽  
One Step

Naturally occurring polysaccharide sulfates are highly diverse, owning variations in the backbone structure, linkage pattern and stereochemistry, branching diversity, sulfate content and positions of sulfate group(s). These structural characteristics bring about diverse sulfated polymers with dissimilar negative charge densities and structure–activity relationships. Herein, we start with a short discussion of techniques needed for extraction, purification, chemical sulfation, and structural characterization of polysaccharides. Processes of isolation and sulfation of plant-derived polysaccharides are challenging and usually involve two steps. In this context, we describe an integrated extraction-sulfation procedure that produces polysaccharide sulfates from natural products in one step, thereby generating additional pharmacological activities. Finally, we provide examples of the spectrum of natural source-derived polysaccharides possessing specific features of bioactivity, in particular focusing on current aspects of antiviral drug development and drug–target interaction. Thus, the review presents a detailed view on chemically engineered polysaccharides, especially sulfated derivatives, and underlines their promising biomedical perspectives.

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