Fixation des dunes et reboisement avec le filao (Casuarina equisetifolia) dans la zone du littoral nord du Sénégal

1994 ◽  
Vol 70 (3) ◽  
pp. 282-290 ◽  
Author(s):  
Daniel Mailly ◽  
Papa Ndiaye ◽  
Hank A. Margolis ◽  
Marius Pineau
Keyword(s):  
Rapid Growth ◽  
Sand Dunes ◽  
Climatic Conditions ◽  
Agricultural Fields ◽  
Northern Coast ◽  
Casuarina Equisetifolia ◽  
The Past ◽  
Potential Source ◽  
Dune Fixation ◽  
Shifting Sand

The northern coast of Senegal is the site of a conservation program with the objective of stabilizing shifting sand dunes in order to protect adjacent agricultural fields against the detrimental effects of wind. Casuarina equisetifolia ("filao"), a nitrogen-fixing tree species indigenous to Oceania and southeast Asia, is the favored species for these dune stabilization efforts. Over the past 40 years, the total area reforested with C. equisetifolia amounts to more than 9700 ha. Due to its rapid growth, particularly in the inter-dune depressions, it is seen as a potential source of wood for the region. Additionally, reforestation efforts have also been directed towards the semi-fixed dunes (2380 ha) and the fixed dunes (4350 ha) lying further inland. Thus, despite the severity of the climatic conditions of recent years, Senegal's dune fixation program is clearly a success in respect to its initial objectives and represents an important step forward in the fight against desertification.

scholarly journals Radiocarbon Dating of Tufa in Paleoclimatic Studies

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 421-427 ◽  
Author(s):  
Dušan Srdoč ◽  
Nada Horvatinčić ◽  
Bogomil Obelić ◽  
Adela Sliepčević
Keyword(s):  
Age Distribution ◽  
Climatic Conditions ◽  
Mean Annual Temperature ◽  
Initial Activity ◽  
The Past ◽  
Potential Source ◽  
Biogenic Carbon ◽  
Calcareous Deposits ◽  
Sample Frequency ◽  
Time Gap

Calcareous deposits known as tufa or travertine contain biogenic carbon and are a potential source of geochronologic information. Many dated samples from Karstic regions in Yugoslavia proved that 14C analyses of tufa can provide reliable data reflecting climatic conditions in the past. Systematic dating of tufa samples revealed two distinct groups of deposits: recent tufa deposits, with a sharp age limit of ∼6000 ± 500 years BP, and old tufa deposits with 14C age ranges from 25,000 ± 2300 years BP to the lowest limit of our 14C dating system (∼37,000 years). A histogram based on the initial activity AO = 0.85 shows the age distribution of randomly sampled tufas vs sample frequency. A time gap between ∼6000 BP and ∼23,000 BP is evident, reflecting cooler climatic conditions. The start of peat deposition is coincident with that of tufa growth in the Holocene.Paleoclimatic implications of tufa growth periods obtained by 14C dating are as follows: climatic conditions that favor tufa formation at least in karstic regions, are very stringent. Therefore, climatic conditions, such as mean annual temperature and humidity, as well as hydrologic and vegetational conditions, must have been very similar in periods of tufa growth. While recent tufa deposits are coincident with the warm Holocene period, old tufa can be associated with warm interstadials in the Würm.

How SIMS microscopy can be used in medicine

1992 ◽  
Vol 50 (2) ◽  
pp. 1602-1603
Author(s):  
Philippe Fragu
Keyword(s):  
Mass Spectrometry ◽  
Biomedical Applications ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Elements ◽  
Biological Applications ◽  
The Past ◽  
Potential Source ◽  
Secondary Ion ◽  
Chemical Integrity ◽  
Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

Sharade Marathe. Regulation and Development: The Indian Policy Experience of Controls Over Industry. New Delhi: Sage Publications India Pvt. Ltd. 1986. 328 pp.Price: (Hardbound edition) Rupees (Indian) 195.00.

1987 ◽  
Vol 26 (2) ◽  
pp. 225-227
Author(s):  
Khwaja Sarmad
Keyword(s):  
Industrial Policy ◽  
Rapid Growth ◽  
Industrial Structure ◽  
Industrial Sector ◽  
Primary Objective ◽  
Indian Policy ◽  
New Delhi ◽  
The Past ◽  
Distinguished Career ◽  
Comprehensive Manner

This book documents in a comprehensive manner the 'twists and turns' in India's industrial policy and strongly suggests the need for a re-orientation of this policy to overcome the weaknesses in the industrial structure and to utilize the sources of its strength. The author has had a distinguished career in the Indian Economic Service and brings this experience to bear on his analysis of the evolution of industrial policy in India. In India, the primary objective of planned development has been the creation of a technologically mature society capable of sustaining a process of self-propelled growth without extreme concentration of wealth in a few hands. It is rightly pointed out in the book that this objective is possible only in the context of rapid growth, which is the ultimate test of industrial policy. The book traces the origins of India's industrial policy and analyses its evolution during the past thirty years, showing how there has been an increasing gap between the objectives of this policy and the performance of the industrial sector.

scholarly journals Application of Reactor Engineering Concepts in Continuous Flow Chemistry: A Review

2021 ◽  
Author(s):  
Nicole Candice Neyt ◽  
Darren Lyall Riley
Keyword(s):  
Rapid Growth ◽  
Continuous Flow ◽  
Flow Chemistry ◽  
The Past ◽  
Continuous Flow Chemistry

The adoption of flow technology for the manufacture of chemical entities, and in particular pharmaceuticals, has seen rapid growth over the past two decades with the technology now blurring the...

scholarly journals Guidelines for Genetic Nomenclature and Community Governance for the Model Legume Medicago truncatula

2001 ◽  
Vol 14 (12) ◽  
pp. 1364-1367 ◽  
Author(s):  
Kathryn A. VandenBosch ◽  
Julia Frugoli
Keyword(s):  
Medicago Truncatula ◽  
Rapid Growth ◽  
Model System ◽  
Gene Nomenclature ◽  
Community Governance ◽  
Model Legume ◽  
The Past ◽  
Genetic Nomenclature ◽  
International Collaborations

At the 2nd Medicago meeting (a satellite of the 1999 IS-MPMI meeting in Amsterdam), investigators perceived a need for standardization of genetic nomenclature in Medicago truncatula, due to the rapid growth of research on this species in the past few years. Establishment of such standards grew out of discussions begun at this meeting and continued electronically throughout the M. truncatula community. The proposed standards presented here are the consensus results of those discussions. In addition to standards for gene nomenclature, a method for community governance and a website for cataloging gene names and submitting new ones are presented. The purpose of implementing these guidelines is to help maintain consistency in the literature, to avoid redundancy, to contribute to the accuracy of databases, and, in general, to aid the international collaborations that have made M. truncatula a model system for legume biology.

Calotropis procera (apple of sodom).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
Sand Dunes ◽  
Fibre Production ◽  
Calotropis Procera ◽  
Desert Grassland ◽  
Evergreen Shrub ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Shifting Sand ◽  
Pale Green

Abstract C. procera is a fleshy evergreen shrub about 1.8-5.5 m tall, with a diameter at breast height of 15-20 cm (von Maydell, 1986). The flowers are pale green to white, with purple tips. A fibre obtained from the bark is used to make lines, bow-strings and twine; it can also be spun with cotton, or used to stuff mattresses and pillows. The fibre is strengthened by soaking in water for 1-2 days, but extensive soaking may reduce durability. The wood is of small dimensions and is too light for most uses. C. procera produces a distinctive white latex, which contains cardiotoxins and hydrocarbons with many medicinal and pesticidal properties. C. procera has been widely planted for fibre production and has become naturalized on the American and Australian continents. It is often abundant on degraded areas and is an indicator of overgrazing. C. procera is a widespread pioneer in semi-desert grassland and bushland (e.g. in Africa), and it also colonizes shifting sand-dunes such as in Rajasthan, India. However, due to its properties as a pioneer, there is a risk that this species may become a weed. More research is needed on C. procera to maximize production and marketing of its many potential products.

scholarly journals Notes on distribution and relative abundances of some animal species, and on climate in the Kruger National Park during prehistoric times

Koedoe ◽  
1989 ◽  
Vol 32 (1) ◽  
Author(s):  
Ina Plug
Keyword(s):  
National Park ◽  
Animal Species ◽  
Climatic Conditions ◽  
Kruger National Park ◽  
Archaeological Sites ◽  
Animal Population ◽  
Faunal Remains ◽  
The Past ◽  
Relative Abundances ◽  
Insight Into

Faunal remains obtained from archaeological sites in the Kruger National Park, provide valuable information on the distributions of animal species in the past. The relative abundances of some species are compared with animal population statistics of the present. The study of the faunal samples, which date from nearly 7 000 years before present until the nineteenth century, also provides insight into climatic conditions during prehistoric times.

scholarly journals Climate Change and Conflict

2019 ◽  
Vol 22 (1) ◽  
pp. 343-360 ◽  
Author(s):  
Vally Koubi
Keyword(s):  
Climate Change ◽  
Climatic Changes ◽  
Climatic Conditions ◽  
Future Research ◽  
General Effect ◽  
Substantial Agreement ◽  
Political Factors ◽  
Academic Literature ◽  
The Past ◽  
Level Of Economic Development

The link between climate change and conflict has been discussed intensively in academic literature during the past decade. This review aims to provide a clearer picture of what the research community currently has to say with regard to this nexus. It finds that the literature has not detected a robust and general effect linking climate to conflict onset. Substantial agreement exists that climatic changes contribute to conflict under some conditions and through certain pathways. In particular, the literature shows that climatic conditions breed conflict in fertile grounds: in regions dependent on agriculture and in combination and interaction with other socioeconomic and political factors such as a low level of economic development and political marginalization. Future research should continue to investigate how climatic changes interact with and/or are conditioned by socioeconomic, political, and demographic settings to cause conflict and uncover the causal mechanisms that link these two phenomena.

scholarly journals Tree Change in Nemoral Spruce Forests of the Central Forest Reserve

2021 ◽  
pp. 459-476
Author(s):  
M. Yu. Pukinskaya
Keyword(s):  
Deciduous Forest ◽  
Climatic Conditions ◽  
Spruce Forest ◽  
Forest Reserve ◽  
Spruce Forests ◽  
The Past ◽  
Broad Leaved Forest ◽  
The Russian Federation ◽  
Leaved Forest

The paper discusses changes in forest-forming species in the nemoral spruce forests of the Central Forest Reserve (Tver Region, the Russian Federation). A comparison is made of the characterization of vegetation in the reserve spruce forests, carried out during the first survey of the reserve by Ya. Ya. Alekseev in 1931 (Alekseev, 1935) with the descriptions of vegetation made by the author from 2011 to 2019. It is shown that the coverage of nemoral herbs in the spruce forests of the reserve has increased over the past 90 years. In addition, three types of broadleaf trees (Tilia cordata Mill., Acer platanoides L. and Ulmus scabra Mill.) have greatly increased their abundance in the stand, most notably the linden. In recent decades, the decay of nemoral spruce forests has been taking place in the Central Forest Reserve. The birch-aspenspruce stand is not replenished with spruce renewal but is replaced by linden-maple forests. The vitality of spruce undergrowth is deteriorating. After the decay of a spruce forest, a change of the tree dominants occurs on 74% of the trial plots and the stand continues with a spruce forest on 26%. The largest part of the reserve's nemoral spruce forests arose after major disturbances 100–150 years ago (on the site of burned-out areas, hurricane windblows and cuttings). Old nemoral spruce forests were formed during the period when severe frosts prevented linden and maple from entering the stand. Currently, the coincidence of climate warming with the aging of the spruce stand and the removal of anthropogenic influence contributed to the release of maple and linden from the undergrowth into the stand and change to a spruce-deciduous forest. Under the prevailing climatic conditions, a return to the spruce forest is possible in the event of a burning out or when the climate becomes cold. The nemoral spruce forest is an ecotone type and, depending on conditions, becomes a spruce or broad-leaved forest.

scholarly journals A Control Theory Approach to Optimal Irrigation Scheduling in the Oklahoma Panhandle

1980 ◽  
Vol 12 (1) ◽  
pp. 165-171 ◽  
Author(s):  
Thomas R. Harris ◽  
Harry P. Mapp
Keyword(s):  
Great Plains ◽  
Crop Production ◽  
Crop Yields ◽  
Low Cost ◽  
Primary Source ◽  
Irrigation Scheduling ◽  
Climatic Conditions ◽  
Theory Approach ◽  
Agricultural Producers ◽  
The Past

Climatic conditions in semiarid regions like the Oklahoma Panhandle result in wide fluctuations in rainfall, dryland crop yields, and returns to agricultural producers in the area. Irrigated crop production increases peracre yields and significantly reduces fluctuations in yields and net returns.Irrigated production of food and fiber in the Oklahoma Panhandle has developed rapidly during the past three decades, increasing from 11,500 to 385,900 acres since 1950 (Schwab). The primary source of irrigation water in the area is the Ogallala Formation, an aquifer underlying much of the Great Plains region. Until the past couple of years, the presence of relatively low cost natural gas led producers to expand irrigated production and apply high levels of water to crops irrigated in the area.

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