scholarly journals Population systems of Eurasian water frogs (Pelophylax) in the south of Ukraine

2020 ◽  
Vol 28 (2) ◽  
pp. 154-162
Author(s):  
N. M. Suriadna ◽  
G. I. Mykytynets ◽  
M. Pupiņš ◽  
V. Y. Gasso
Keyword(s):  
Taxonomic Diversity ◽  
Mixed Population ◽  
Large Rivers ◽  
Mixed System ◽  
The South ◽  
Isolated Populations ◽  
Sex Structure ◽  
Water Frogs ◽  
Wide Range ◽  
Freshwater Bodies

Ecological and evolutionary consequences of population-genetic processes that occur because of natural cross-species hybridization can show mechanisms of overcoming the reproductive barrier and obtaining the species status by a hybrid taxon. This is clearly seen in the population systems of Eurasian water frogs – Pelophylax esculentus complex. The P. esculentus (E) hybrid usually discards one of the parental genomes of P. lessonae (L) or P. ridibundus (R) and reproduces semi-clonally. The genetic structure and direction of gene flows precisely depend on the type and distribution of mixed or pure population systems of water frogs. Three population systems in the south of Ukraine were identified and confirmed as RR, RE and REL. The populations of P. ridibundus are most common (76.2%). A mixed population systems of P. ridibundus and P. esculentus (20.0%) are concentrated in the floodplains of large rivers where triploids were found and the unisexual hybrids (1.0♂ : 0.1♀) were proved. Parent species populations having different ploidy of P. esculentus such as 3n and for the first time 4n were found. A mixed system of three taxa (REL) is rare (3.8%) and locally concentrated in the lower Danube and Dnieper with the smallest proportion of P. lessonae. We did not find populations of P. lessonae (LL), P. esculentus (EE, very rare system of hybrids only), and two mixed populations of parental species RL and semi-clonal LE in the south of Ukraine, but they are known for northern areas. The high number of P. ridibundus tends to decrease; the scarce P. esculentus and the extremely rare P. lessonae require special conservation measures. P. ridibundus (RR) occupies a wide range of diverse natural, permanent, temporary, coastal, continental, and artificial freshwater bodies, including synanthropic ecosystems. Mixed population systems inhabit willow and poplar forests in the floodplains of large rivers. In the south of Ukraine rare and isolated populations of the water frogs occurring outside the main range can be relict. Biotopic preferences, ratio and number of constituent taxa are crucial for an adequate assessment of biological (taxonomic) diversity and development of an appropriate strategy for the population systems’ conservation. Such characteristics as unisexuality of hybrids, their spreading patterns, specific sex structure and ploidy in different population systems of the P. esculentus complex contribute to the understanding of the hybridogenetic dynamics; produce new tendencies of becoming independent hybridogenous taxa and emergence of new evolutionary relationships.

scholarly journals Microalgal taxonomic diversity from shallow acidophilus freshwater bodies from the south of Chile

2019 ◽  
Vol 76 (2) ◽  
pp. 189-207
Author(s):  
Mariela A. González ◽  
Ingrid De L. Inostroza ◽  
Visitación Conforti ◽  
Enrique Ascencio
Keyword(s):  
Taxonomic Diversity ◽  
The South ◽  
Freshwater Bodies

scholarly journals Global database of ratios of particulate organic carbon to thorium-234 in the ocean: improving estimates of the biological carbon pump

2020 ◽  
Vol 12 (2) ◽  
pp. 1267-1285 ◽  
Author(s):  
Viena Puigcorbé ◽  
Pere Masqué ◽  
Frédéric A. C. Le Moigne
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Mixed Layer Depth ◽  
Sediment Traps ◽  
Data Repository ◽  
The South ◽  
South Indian ◽  
Wide Range ◽  
Carbon Pump ◽  
Biological Carbon Pump

Abstract. The ocean's biological carbon pump (BCP) plays a major role in the global carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer as settling particles (e.g., marine snow). Since the seminal works on the BCP, global estimates of the global strength of the BCP have improved but large uncertainties remain (from 5 to 20 Gt C yr−1 exported below the euphotic zone or mixed-layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage of allowing a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to the POC∕234Th ratio in sinking particles. However, the factors controlling the regional, temporal, and depth variations of POC∕234Th ratios are poorly understood. We present a database of 9318 measurements of the POC∕234Th ratio in the ocean, from the surface down to >5500 m, sampled on three size fractions (∼>0.7 µm, ∼1–50 µm, ∼>50 µm), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived in the data repository PANGAEA® under https://doi.org/10.1594/PANGAEA.911424 (Puigcorbé, 2019). The samples presented in this dataset were collected between 1989 and 2018, and the data have been obtained from published papers and open datasets available online. Unpublished data have also been included. Multiple measurements can be found in most of the open ocean provinces. However, there is an uneven distribution of the data, with some areas highly sampled (e.g., China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific, and the south Indian oceans. Some coastal areas, although in a much smaller number, are also included in this global compilation. Globally, based on different depth horizons and climate zones, the median POC∕234Th ratios have a wide range, from 0.6 to 18 µmol dpm−1.

scholarly journals Alternatives to Bankruptcy in South Africa that Provides for a Discharge of Debts: Lessons from Kenya

2019 ◽  
Vol 22 ◽  
pp. 1-34
Author(s):  
Zingaphi Mabe
Keyword(s):  
South Africa ◽  
South African ◽  
The South ◽  
Insolvency Law ◽  
Debt Restructuring ◽  
Wide Range ◽  
Insolvency Proceedings ◽  
National Credit Act

The problems faced by debtors in South Africa is not that there are no alternatives to insolvency proceedings, but that the available alternatives do not provide for a discharge of debt as with a sequestration order, which is ultimately what the debtor seeks to achieve. Debtors in South Africa can make use of debt review in terms of the National Credit Act 34 of 2005 or administration orders in terms of the Magistrates' Court Act 32 of 1944 to circumvent the sequestration process. However, both debt review and administration orders do not provide for a discharge of debt and provide for debt-restructuring only, in order to eventually satisfy the creditor's claims. Attention is given to the sequestration process and the alternatives to sequestration as they relate specifically to the discharge or lack of a discharge of a debtor's debts. The South African law is compared to Kenyan Law. This article seeks to analyse the alternatives to the bankruptcy provisions of the newly enacted Kenyan Insolvency Act 18 of 2015 in order to influence the possible reform of insolvency law in South Africa. Like the South African Insolvency Act, the old Kenyan Bankruptcy Act (Cap 53 of the Laws of Kenya) also did not have alternatives to bankruptcy. The old Kenyan Bankruptcy Act, however, contained a provision on schemes of arrangement and compositions. The Kenyan Insolvency Act now caters for alternatives to bankruptcy and provides a wide range of alternatives to bankruptcy, some of which allow debtors in different financial positions to obtain a discharge.    

scholarly journals Maritime Aerosol Optical and Microphysical Properties in the South China Sea Under Multi-source Influence

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chi Zhang ◽  
Hua Xu ◽  
Zhengqiang Li ◽  
Yisong Xie ◽  
Donghui Li
Keyword(s):  
South China Sea ◽  
South China ◽  
Volume Concentration ◽  
The South China Sea ◽  
Skewed Distribution ◽  
The South ◽  
China Sea ◽  
Microphysical Properties ◽  
Wide Range ◽  
Fine Mode

AbstractThe South China Sea hosts a wide range of aerosol pollutants with the uneven development of socio-economic and complicated meteorology system. To fill the gap of the maritime aerosol characteristics over the sea, we selected the multi-year ground-based measurements of Taiping Site and Dongsha Site to investigate the optical and microphysical properties. In Taiping, the vast majority of aerosol optical depths (AODs) are less than 0.2, but that of Dongsha shows the wider distribution of AODs from 0 to 0.6. Angstrom Exponent frequency distribution in Taiping peaks at the range of 0.75–1.25 but that has the left-skewed distribution in Taiping Island. Moreover, there is a variation in the coarse-mode volume concentration in Taiping Island but less variation in the fine mode. The seasonal maritime aerosol properties of Taiping and Dongsha have been analyzed that can be employed as a maritime look up table (LUT) kernel in coupled atmospheric retrieval and correction algorithms.

The Style of the Neo-Greek (Neo-Grec) in the Historical and Cultural Context of the Southern Region of Russia by the Example of the Cities of Rostov-on-Don and Yessentuki

2018 ◽  
Vol 931 ◽  
pp. 705-710 ◽  
Author(s):  
Eugenia M. Kishkinova
Keyword(s):  
National Identity ◽  
Cultural Context ◽  
Southern Region ◽  
Main Task ◽  
The South ◽  
Distinctive Features ◽  
Wide Range ◽  
Insufficient Knowledge ◽  
European Architecture

In European architecture the Neo-Grec style, based on a revival of Greek principles and motifs, is an independent stage in rediscovering of classical antique heritage. It is one of the “new styles” of a historicist phase in architecture that claimed to find national identity in the architecture of independent Greece. In Russian architecture of the mid-19th – early 20th centuries this style is represented in a wide range of monuments that are mostly located in the South of Russia. However insufficient knowledge and research on the monuments of this style create difficulties for their maintenance and restoration. The purpose of the paper is to identify distinctive features of neo-grec in the region. The main task is to determine the reasons for a turn to neo-grec in the South of Russia, to identify and analyze neo-grec buildings in the cities of Rostov-on-Don and Yessentuki, to examine their composition and décor, to identify their ancient prototypes, to differentiate constant and variable elements in the architecture of the Neo-Grec.

Conservation strategies for Africa's large mammals

2001 ◽  
Vol 13 (8) ◽  
pp. 459 ◽  
Author(s):  
J. Hanks
Keyword(s):  
Protected Areas ◽  
National Parks ◽  
Economic Value ◽  
Sustainable Land Use ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Large Mammals ◽  
Isolated Populations ◽  
African Mammals ◽  
Wide Range

Africa’s large mammals are conserved for their aesthetic, scientific and economic values. Many of these species face a gloomy future precipitated by a combination of factors directly and indirectly influenced by the activities of man, including habitat loss, overexploitation, poor management of designated protected areas, and the vulnerability of small isolated populations. Africa’s designated protected areas and biodiversity hotspots are also under threat, highlighting the importance of embracing community participation to address accelerating poverty and malnutrition. Innovative strategies are required for the conservation of Africa’s mammals, such as the integration of a wide range of species in the production landscape, including the farming community. Transfrontier conservation areas (TFCAs) have been established with the combined objectives of conserving biodiversity, creating new jobs in the tourism and wildlife industry, and promoting a culture of peace. These areas extend far beyond traditional national parks, providing opportunities for integrating large mammals into sustainable land-use practices, at the same time as addressing some of the continent’s more pressing socioeconomic needs. Research on African mammals will inevitably have to change direction to accommodate the growing threats and changed circumstances. Priorities will include the identification of corridors associated with TFCA establishment, the determination of the economic value of certain species in consumptive use programmes, research on contraception as a management option in restricted areas, and further work on the indirect use value of species. There will also be worthwhile opportunities to be pursued with ex situ conservation programmes, but these need to be focussed more efficiently.

SURFACE FACILITIES FOR OILFIELDS IN THE SOUTH AUSTRALIAN SECTOR OF THE COOPER BASIN

1986 ◽  
Vol 26 (1) ◽  
pp. 470
Author(s):  
R.J. Scanlan ◽  
C.J. White
Keyword(s):  
Net Present Value ◽  
Task Force ◽  
Development Project ◽  
Project Planning ◽  
Present Value ◽  
The South ◽  
Field Development ◽  
Variable Nature ◽  
Wide Range ◽  
Cooper Basin

Delhi Petroleum Pty Ltd, as operator, has been responsible for the development of eight oilfields in the South Australian sector of the Cooper Basin since 1982. Some of these field developments are economically marginal, hence the need to optimise those aspects of the facilities which impact on the ongoing cost of production and the overall profitability. A phased development approach has evolved over the past three years to reduce the external financing requirements and to improve the certainty of the data used to define the key elements of each project.For the successful completion of the project a task force approach to project management is utilised, supported by the use of computerised project planning and control systems. Further, it is important to define and agree on the design criteria and philosophy for the project at the commencement, this providing a base by which to measure scope changes, and so that all concerned are working to a common goal.The use of economic analysis as a decision-making tool during all phases of the project assists the project team to home in on the key objective which is to maximise the project net present value. Comparative economics and sensitivity analysis are used at the conceptual stage to select the preferred development option, e.g. pipeline versus trucking.The design of surface facilities is dictated by a wide range of criteria including the above development philosophy. The variable nature of these criteria demonstrates that each new field development must normally be engineered individually to ensure the target of maximum net present value can be achieved.The Gidgealpa Crude Oil Development Project demonstrates the effectiveness of the above methodology and philosophies. The field was discovered in August 1984, and early production and trucking of oil commenced in January 1985 with 374 000 bbls produced prior to commissioning of the pipeline to Moomba in September 1985.

Diversity and distribution of entomopathogenic nematodes in Chile

Nematology ◽  
2010 ◽  
Vol 12 (6) ◽  
pp. 915-928 ◽  
Author(s):  
Steve Edgington ◽  
Alan G. Buddie ◽  
Dave Moore ◽  
Andrés France ◽  
Loreto Merino ◽  
...  
Keyword(s):  
Entomopathogenic Nematodes ◽  
Atacama Desert ◽  
Soil Samples ◽  
Ex Situ ◽  
Steinernema Feltiae ◽  
Coastal Zones ◽  
The South ◽  
Wide Range ◽  
Natural Hosts ◽  
Northern Regions

Abstract A systematic programme of surveys for entomopathogenic nematodes (EPN) was done in Chile between 2006 and 2008. The survey spanned the principal ecosystems of mainland Chile as well as a number of islands, and covered a wide range of habitats including the Atacama Desert, Andean Altiplano, temperate rainforests and subpolar territory. Nearly 1400 soil samples were collected, of which 7% were positive for EPN. Of 101 EPN isolates obtained, 94 were Steinernema spp. and seven were Heterorhabditis sp. Of the 94 Steinernema isolates, 39 were identified as Steinernema feltiae, the remainder being distributed between two new species, S. unicornum (52 records) and S. australe (three records). The Heterorhabditis isolates, all designated as Heterorhabditis sp.1, are referred to herein as H. cf. safricana. Steinernema feltiae and S. unicornum were collected predominately in the south of Chile and were obtained from a range of habitats, including forests, open grassland, montane soils and coastal zones; neither species was recovered from the far north of the country (viz., desert soils in the Norte Grande region). Steinernema australe was found in only three soil samples, all from humid, cool, coastal localities in the south. Heterorhabditis cf. safricana was recovered from the northern regions, with most isolates found in or on the periphery of the Atacama Desert; they were not recovered from cooler, more humid regions of southern Chile. Molecular information indicated there were two subgroups of both S. unicornum and S. feltiae, with a geographical, intraspecific split of subgroups between the most southerly and the more central survey zones. All isolates were collected by ex situ baiting with waxmoth larvae and the natural hosts are unknown.

scholarly journals At Least Two Origins of Fungicide Resistance in Grapevine Downy Mildew Populations

2007 ◽  
Vol 73 (16) ◽  
pp. 5162-5172 ◽  
Author(s):  
Wei-Jen Chen ◽  
François Delmotte ◽  
Sylvie Richard Cervera ◽  
Lisette Douence ◽  
Charles Greif ◽  
...  
Keyword(s):  
Plant Pathogen ◽  
Fungicide Resistance ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Plasmopara Viticola ◽  
Isolated Populations ◽  
Grapevine Downy Mildew ◽  
First Case ◽  
Wide Range ◽  
Pathogen Populations

ABSTRACT Quinone outside inhibiting (QoI) fungicides represent one of the most widely used groups of fungicides used to control agriculturally important fungal pathogens. They inhibit the cytochrome bc 1 complex of mitochondrial respiration. Soon after their introduction onto the market in 1996, QoI fungicide-resistant isolates were detected in field plant pathogen populations of a large range of species. However, there is still little understanding of the processes driving the development of QoI fungicide resistance in plant pathogens. In particular, it is unknown whether fungicide resistance occurs independently in isolated populations or if it appears once and then spreads globally by migration. Here, we provide the first case study of the evolutionary processes that lead to the emergence of QoI fungicide resistance in the plant pathogen Plasmopara viticola. Sequence analysis of the complete cytochrome b gene showed that all resistant isolates carried a mutation resulting in the replacement of glycine by alanine at codon 143 (G143A). Phylogenetic analysis of a large mitochondrial DNA fragment including the cytochrome b gene (2,281 bp) across a wide range of European P. viticola isolates allowed the detection of four major haplotypes belonging to two distinct clades, each of which contains a different QoI fungicide resistance allele. This is the first demonstration that a selected substitution conferring resistance to a fungicide has occurred several times in a plant-pathogen system. Finally, a high population structure was found when the frequency of QoI fungicide resistance haplotypes was assessed in 17 French vineyards, indicating that pathogen populations might be under strong directional selection for local adaptation to fungicide pressure.

Occurrence and distribution of root-knot nematodes, Meloidogyne spp., in cowpea growing areas of Nigeria

Nematology ◽  
2004 ◽  
Vol 6 (6) ◽  
pp. 811-817 ◽  
Author(s):  
Tayo Olowe
Keyword(s):  
Population Density ◽  
Mixed Population ◽  
The South ◽  
Root Knot Nematodes ◽  
Humid Forest ◽  
North West ◽  
Ecological Zones ◽  
The Core ◽  
North East ◽  
Meloidogyne Spp

AbstractA survey of root knot nematodes, Meloidogyne spp., was conducted in 248 major cowpea growing areas, spread over 31 States and the Federal Capital Territory in different ecological zones in Nigeria. The survey revealed the occurrence of Meloidogyne incognita, M. javanica and M. arenaria singly or in combination in all the cowpea farms sampled. In overall distribution, M. incognita (51.8%) was the most prevalent followed by M. javanica (44.1%) and M. arenaria (4.1%). The greatest abundance of M. javanica (65.6%) was concentrated in the Sudan savannah of the Core North (north-east and north-west) and that of M. incognita (82.1%) in the humid forest of the south (south-east, south-west and south-south). However, M. javanica (51.7%) and M. incognita (44.2%) tended to be common in the Guinea savannah of the middle belt (north-central). Mixed populations of the three species (4.0%), but more commonly of M. incognita and M. javanica (37.1%), were encountered. Meloidogyne arenaria never occurred as a pure population or mixed with M. javanica solely but was found mixed either with M. incognita alone or in combination with M. javanica and M. incognita, and more often in the south. In a mixed population of M. incognita and M. javanica in the Core North, where M. javanica was prevalent, M. incognita formed about one third (34.2%) of the mixed population density, whereas in the south where M. incognita was dominant, M. javanica formed a lower proportion of about one fifth (17%) of the mixed population density. These findings provide information and guidance for planning effective management strategies.

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