Climatic indices for determining risks to the distribution and maintenance of Quercus emoryi Torr. (Fagaceae) in Mexico

2014 ◽  
Vol 36 (5) ◽  
pp. 483 ◽  
Author(s):  
Maria de Jesus Torres-Meza ◽  
Alma Delia Baez-Gonzalez ◽  
Jose Luis Ramos-Gonzalez
Keyword(s):  
Species Conservation ◽  
Ex Situ ◽  
Climate Indices ◽  
Limiting Factor ◽  
Climate Variables ◽  
Quercus Emoryi ◽  
Potential Benefits ◽  
At Risk Populations ◽  
Weather Stations

Mexico is one of the two centres of diversification of oaks (Quercus spp.) in the world, with 161 species, 66% of which are endemic. The local-scale analysis of trends in climate variables, using climate indices, can be useful in estimating both the potential benefits and risks presented by climate to oak populations. Since the minimum January temperature is an important limiting factor in the distribution of Quercus emoryi Torr. in Mexico, this study analysed trends in this variable in the area of distribution of the species and identified the populations likely to be affected by them. The RClimDex 1.0 software was used to analyse trends of nine climate indices related to minimum temperature recorded in 14 weather stations in the area of the species’ potential distribution in Mexico. Data from five stations showed significant trends related to an increase in minimum January temperature, whereas data from seven stations showed trends of a decrease in this variable. Populations of the species, mainly in the ecoregion containing piedmonts and plains with grassland, scrubland and forests in the Cuauhtemoc region in Chihuahua state, and Cuencame and Canatlan regions in Durango state, could be affected by these trends. The information on at-risk populations may be used for in situ and ex situ species conservation programs.

scholarly journals Copulatory behavior of Knuckles pygmy lizard (Cophotis dumbara)

2021 ◽  
Vol 10 (2) ◽  
pp. 128-130
Author(s):  
H.D.C. Soysa ◽  
U.S.B. Hettige ◽  
M.G. Cooray ◽  
D.R. Vidanapathirane
Keyword(s):  
Natural History ◽  
Habitat Loss ◽  
Ex Situ Conservation ◽  
Species Conservation ◽  
Copulatory Behavior ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Reproductive Behaviors ◽  
The World

Nearly one in every five species of reptiles in the world is threatened with extinction and thus is conservation dependent. In order to develop effective and targeted species conservation strategies, detailed information on their distribution, systematics and ecology are necessary. Information such as the natural history and in-situ reproductive behaviors would be crucial for highly threatened species that require ex-situ conservation measures. Agamid lizards are a major component of the global reptile diversity and a significant number are threatened due to habitat loss and other threats such as smuggling.

scholarly journals Selección cualitativa del esqueje en la sobrevivencia y desarrollo morfogenético de Vanilla planifolia Andrews

2018 ◽  
Vol 29 (3) ◽  
pp. 616 ◽  
Author(s):  
José Bernal Azofeifa-Bolaños ◽  
German Rivera-Coto ◽  
Amelia Paniagua-Vásquez ◽  
Roberto Cordero-Solórzano
Keyword(s):  
Costa Rica ◽  
In Situ Conservation ◽  
Species Conservation ◽  
Mechanical Damage ◽  
Ex Situ ◽  
Shoot Number ◽  
In The Wild ◽  
First Time ◽  
Integrated Program

In Costa Rica, an urgent ex situ national conservation program for V. planifolia is needed due to the rarity, high risk of extinction in the wild and the economic importance; that places it, as the most profitable orchid worldwide. Due to the lack of research about wild species conservation and the importance to evaluate the agronomic performance of the wild-type relatives, as a strategy to increase the reduced genetic variability, the aim of this research was to evaluate the acclimatization capacity and morphogenetic performance of wild V. planifolia under nursery conditions. The effect of two treatments 1) qualitatively selected cuttings according to their phytosanitary quality, mechanical damage and vigorousness and 2) cuttings without selection, were evaluated. Some growth variables were evaluated: survival rate, weight, length, number of nodes of the new and original shoot; number and weight of the roots The survival of the selected cuttings was greater (60%) than those that were not (45%). The morphogenetic responses of the selected explants were statistically significant for all variables evaluated. This is the first time that an initial process of acclimatization and morphogenetic performance with a known genotype individual of V. planifolia, is reported under greenhouse condition, in Costa Rica. Therefore, it is the first attempt to the ex situ conservation of the species as a part of an integrated program focus on the in situ conservation in a systematic and sustainable way, as well as, the first values of the vigorousness to some growth variables out of natural conditions.

scholarly journals Agrobiodiversity and its Conservation in Nepal

2020 ◽  
Vol 6 ◽  
pp. 14-33
Author(s):  
Bal Krishna Joshi ◽  
Neena Amatya Gorkhali ◽  
Neeta Pradhan ◽  
Krishna Hari Ghimire ◽  
Tek Prasad Gotame ◽  
...  
Keyword(s):  
Conservation Status ◽  
Group Discussion ◽  
Species Conservation ◽  
Geographical Information ◽  
Ex Situ ◽  
Aquatic Animal ◽  
Global Marketing ◽  
Good Practices ◽  
On Farm

Nepal is a part of the world’s biodiversity hotspot and ranks the 49th in the world for biodiversity. Agrobiodiversity and its conservation status were studied through literature review, field survey, key informant survey and focus group discussion. Results of field implementation of some good practices and action research were also documented. Among 24,300 total species in the country, 28% are agricultural genetic resources (AGRs), termed as agrobiodiversity. Agrobiodiversity has six components (crops, forages, livestock, aquatic, insects and microorganisms) and four sub-components (domesticated, semi-domesticated, wild relatives and wild edible) in Nepal. Agrobiodiversity on each component exists at agroecosystem, species, variety/breed/biotype/race/strain, genotype and allele levels, within an altitude range from 60 to 5,000 masl. There are 12 agroecosystems supporting 1026 species under crop component, 510 under forage, 35 under livestock, 250 under the aquatic animal, 17 under aquatic plant, 3,500 under insect and 800 under microorganism. An estimated loss of agrobiodiversity is 40%, however, farmers have reported up to 100% loss of AGRs in some areas for a particular species. Conservation of agrobiodiversity has been initiated since 1986. Four strategies namely ex-situ, on-farm, in-situ and breeding have been adopted for conservation and sustainable utilization of AGRs. Eighty good practices including process, methods and actions for managing agrobiodiversity have been in practice and these practices come under five conservation components (sensitization, method and approach, accelerator, value and enabling environment). Within the country, 18,765 accessions of AGRs have been conserved in different kinds of banks. A total of 24,683 accessions of Nepalese crops, forages and microbes have been conserved in different international and foreign genebanks. Some collections are conserved as safety duplication and safety backup in different CGIARs’ banks and World Seed Vault, Korea. Two global databases (GENESYS and EURISCO) have maintained 19,200 Nepalese accessions. Geographical Information System, Climate Analog Tool and biotechnological tools have been applied for better managing AGRs. Many stakeholders need to further concentrate on the conservation and utilization of AGRs. Global marketing of some native AGRs is necessary for sustaining agriculture and attracting young generations as well as conserving them through use.

scholarly journals Promotion of in situ Forest Farmed American Ginseng (Panax quinquefolius L.) as a Sustainable Use Strategy: Opportunities and Challenges

2021 ◽  
Vol 9 ◽  
Author(s):  
Hong Liu ◽  
Eric P. Burkhart ◽  
Vivian Yi Ju Chen ◽  
Xi Wei
Keyword(s):  
Species Conservation ◽  
Sustainable Use ◽  
American Ginseng ◽  
Ex Situ ◽  
Eastern United States ◽  
Product Certification ◽  
Wild Fauna ◽  
Trade Partners ◽  
Development And Evolution

The cultivation of wild-harvested plant species is one strategy to achieve species conservation while meeting continued demand. A limitation to this approach for species used in Traditional Chinese Medicine, however, is that products produced under ex situ artificial agricultural conditions are often not a perfect replacement for their wild-collected counterparts, so demand for wild-harvested materials persists. This situation applies to American ginseng, an internationally protected species by the Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES) since 1975. In this paper, we trace the trade the history and conservation need for American ginseng in North America, including a summary of the development and evolution of in and ex situ cultivation methods. We report results from a preliminary survey of product labeling of American ginseng sold online in China and adjacent regions and provide recommendations for promoting forest farmed ginseng to consumers as a sustainable use strategy. We suggest that the use of CITES’s new “human assisted” production category amongst trade partners, coupled with “green” product certification and e-commerce platforms, provides a new opportunity to encourage consumption of wild-cultivated rather than wild ginseng in east Asia, and the continued development of ginseng forest farming and supply transparency mechanisms in the eastern United States.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

PROPUESTA DE CONSERVACIÓN DE TRES ESPECIES MEXICANAS DE PICEA EN PELIGRO DE EXTINCIÓN

2015 ◽  
Vol 38 (3) ◽  
pp. 235 ◽  
Author(s):  
Eduardo Mendoza-Maya ◽  
Judith Espino-Espino ◽  
Carmen Z. Quiñones-Pérez ◽  
Celestino Flores-López ◽  
Christian Wehenkel ◽  
...  
Keyword(s):  
Ex Situ

Picea mexicana Martínez, P. chihuahuana Martínez y P. martinezii Patterson son especies endémicas de México en peligro de extinción. Se presenta una síntesis de su situación actual y una propuesta de manejo para su conservación in situ y ex situ, con base en la diversidad y estructura genética de las poblaciones y la ubicación de las áreas en donde se predice existirá el hábitat climático que les es propicio en el futuro (años 2030, 2060 y 2090; al promediar los modelos Canadiense, Hadley y Geofísica de Fluidos con escenarios de emisiones A y B). Para la conservación in situ se plantea la protección, el incremento de la diversidad genética y la expansión de las tres únicas poblaciones de P. mexicana, las cuatro únicas de P. martinezii y ocho poblaciones designadas prioritarias de las 40 poblaciones de P. chihuahuana, mediante la plantación de individuos originados de otras poblaciones hasta alcanzar un tamaño mínimo de población genéticamente viable (entre 1035 a 3836 individuos). Para la conservación ex situ se propone el establecimiento de poblaciones en sitios fuera del rango de distribución natural de las especies, en donde se ha proyectado que ocurrirá el clima que les es propicio, con al menos 3606 individuos de P. mexicana en el volcán Cofre de Perote, Veracruz; 2431 individuos de P. chihuahuana en el municipio de Guanaceví, Durango; y 3092 individuos de P. martinezii en la región de Tlatlauquitepec, Puebla, con plantas originadas de una mezcla de semillas colectadas de árboles al azar de poblaciones específicas.

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