Stochastic Risk and Uncertainty Analysis for Shale Gas Extraction in the Karoo Basin of South Africa

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Abdon Atangana

2014-01-01

Full Text Available We made use of groundwater flow and mass transport equations to investigate the crucial potential risk of water pollution from hydraulic fracturing especially in the case of the Karoo system in South Africa. This paper shows that the upward migration of fluids will depend on the apertures of the cement cracks and fractures in the rock formation. The greater the apertures, the quicker the movement of the fluid. We presented a novel sampling method, which is the combination of the Monte Carlo and the Latin hypercube sampling. The method was used for uncertainties analysis of the apertures in the groundwater and mass transport equations. The study reveals that, in the case of the Karoo, fracking will only be successful if and only if the upward methane and fracking fluid migration can be controlled, for example, by plugging the entire fracked reservoir with cement.

Lithostratigraphy and depositional environments in the Waterberg-Erongo area, central Namibia, and correlation with the main Karoo Basin, South Africa

Science.gov (United States)

Holzförster, Frank; Stollhofen, Harald; Stanistreet, Ian G.

1999-07-01

The dissected landscape of the Waterberg-Erongo area, central Namibia, exposes Karoo-equivalent strata deposited in basins that occur throughout sub-Saharan Africa. Although many are of economic interest, including coal-bearing strata, their depositional history is not well understood. This study of the Waterberg-Erongo area provides detailed lithostratigraphical data, which suggest sedimentation from the late Early Triassic to the Early Jurassic in a fault-bounded depository. Subsidence and sediment supply were controlled predominantly by the northeast-southwest trending Waterberg-Omaruru Fault Zone, which defines the northwestern margin of the depository. Facies development and thickness distribution of the Karoo strata in the Waterberg-Erongo area, perhaps the most continuous of any of the Karoo basins, indicate a northeastwardly-migrating depocentre alongside that fault, in response to major extensional movements in the early pre-South Atlantic rift zone. Periodic fault movements repeatedly caused basinward progradation of the alluvial facies, which are reflected by stacked fining-upward cycles in the lithological record. On a broader scale, the results of this study suggest that the northward propagation of the rift zone between Southern Africa and South America, was partially accommodated by transfer lineaments. Local depocentres developed along these lineaments, such as those in the Waterberg-Erongo area, with localised enhanced subsidence greater than that revealed in other Namibian onshore exposures, dominated by the rifting itself.

Breccia pipes in the Karoo Basin, South Africa, as conduits for metamorphic gases to the Early Jurassic atmosphere

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Silkoset, Petter; Svensen, Henrik; Planke, Sverre

2014-05-01

The Toarcian (Early Jurassic) event was manifested by globally elevated temperatures and anoxic ocean conditions that particularly affected shallow marine taxa. The event coincided with the emplacement of the vast Karoo-Ferrar Large Igneous Province. Among the suggestions for trigger mechanisms for the climatic perturbation is metamorphic methane generation from black shale around the sills in the Karoo Basin, South Africa. The sill emplacement provides a mechanism for voluminous in-situ production and emission of greenhouse gases, and establishes a distinct link between basin-trapped and atmospheric carbon. In the lower stratigraphic levels of the Karoo Basin, black shales are metamorphosed around sills and the sediments are cut by a large number of pipe structures with metamorphic haloes. The pipes are vertical, cylindrical structures that contain brecciated and baked sediments with variable input of magmatic material. Here, we present borehole, petrographic, geochemical and field data from breccia pipes and contact aureoles based on field campaigns over a number of years (2004-2014). The metamorphism around the pipes show equivalent metamorphic grade as the sediments around nearby sills, suggesting a more prominent phreatomagmatic component than previously thought. The stratigraphic position of pipes and the breccia characteristics strengthens the hypothesis of a key role in the Toarcian carbon isotope excursion.

The physical environment and major plant communities of the Karoo National Park, South Africa

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Francine Rubin

1996-08-01

Full Text Available The major plant communities of the Karoo National Park are described using the methods of the Zurich-Montpellier school of phytosociology, to assist with the formulation of a management strategy for the park. The vegetation physiognomy consists of Montane Karoo grassy shrublands. Karoo grassy dwarf shrublands. Karoo succulent dwarf shrublands and riparian thicket. Steep elevation and precipitation gradients within the study area have a direct impact on gradients in the vegetation. High elevation (1 800 m, and relatively high rainfall (406 mm montane grasslands occupy communities dominated by grasses (Merxmuellera disticha, Themeda triandra and woody species (Diospyros austro-africana, Elytropappus rhinocerotis, Euryops annae, Passerina montana. The increasing aridity away from the escarpment edge in a northerly direction is steep, and Montane Karoo dwarf shrublands replace these mesic communities. Species such as Eriocephalus ericoides, Rosenia oppositifolia and Pteronia tricephala dominate. At lower elevation (800 m the precipitation is very low (175 mm and uncertain (coefficient of variation of 78 . The substrata influence the vegetation, with the sandy substrata of the drainage lines supporting more woody taxa (Acacia karroo, Lycium cinereum and grasses (Hyparrhenia hirta, Stipagrostis namaquensis, Cenchrus ciliaris. Moving away from the mesic environment of the riparian zone, rapid desiccation occurs and the most xeric communities are encountered, dominated by Stipagrostis obtusa, S. ciliata and Pent-da incana. This document provides descriptions of the general communities and their associated landscape, lithology and soils.

Constraining the sedimentology and stratigraphy of submarine intraslope lobe deposits using exhumed examples from the Karoo Basin, South Africa

OpenAIRE

Flint, Stephen; Hodgson, David; Spychala, Yvonne; Mountney, Nigel

2017-01-01

Intraslope lobe deposits provide a process record of the infill of accommodation on submarine slopes and their recognition enables the accurate reconstruction of the stratigraphic evolution of submarine slope systems. Extensive exposures of discrete sand-prone packages in Units D/E and E, Fort Brown Formation, Karoo Basin, South Africa, permit analysis of the sedimentology and stacking patterns of three intraslope lobe complexes and their palaeogeographic reconstruction via bed-scale analysis...

South African Journal of Geomatics, Vol. 4, No. 3, August 2015 The ...

African Journals Online (AJOL)

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supplement Municipal water supply but the process is expensive primarily ... Municipality in the Klein Karoo has embarked upon the exploration of a deep ... capability, no telecommunication options and 11Mb of available memory space.

Description of a method for assessing veld condition in the Karoo ...

African Journals Online (AJOL)

Keywords: Canopy-spread cover; Current grazing capacity; Dry matter; Ecological index method; Forage; Grazing-index method; Karoo; Line-point survey method; Strikes; Veld condition; Veld condition index; botany; method; south africa; razing-index method; razing capacity; ine-point survey method; eld condition index

Magnetic investigation and 2½ D gravity profile modelling across the Beattie magnetic anomaly in the southeastern Karoo Basin, South Africa

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Baiyegunhi, Christopher; Gwavava, Oswald

2017-03-01

The southeastern Karoo Basin is considered to be one of the most prospective areas for shale gas exploration in South Africa. An interesting magnetic anomaly, the Beattie magnetic anomaly (BMA), and geologic intrusions are seen on the magnetic map. To date, the source of the BMA and interconnectivity of the igneous intrusions are not well understood. In this study, we investigate the interconnectivity of the igneous intrusions and possible location of the source of the BMA using gravity and magnetic methods. The gravity model results showed that igneous intrusions are interconnected at depth, which probably pose threat by increasing the risk of fracking the Karoo for shale gas exploration. The magnetic results revealed that the BMA becomes stronger with depth. The average depths to the top of the shallow and deep magnetic sources were estimated to be approximately 0.6 and 15 km, respectively.

Deflating the shale gas potential of South Africa's Main Karoo basin

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Michiel O. de Kock

2017-09-01

Full Text Available The Main Karoo basin has been identified as a potential source of shale gas (i.e. natural gas that can be extracted via the process of hydraulic stimulation or ‘fracking’. Current resource estimates of 0.4–11x109 m3 (13–390 Tcf are speculatively based on carbonaceous shale thickness, area, depth, thermal maturity and, most of all, the total organic carbon content of specifically the Ecca Group’s Whitehill Formation with a thickness of more than 30 m. These estimates were made without any measurements on the actual available gas content of the shale. Such measurements were recently conducted on samples from two boreholes and are reported here. These measurements indicate that there is little to no desorbed and residual gas, despite high total organic carbon values. In addition, vitrinite reflectance and illite crystallinity of unweathered shale material reveal the Ecca Group to be metamorphosed and overmature. Organic carbon in the shale is largely unbound to hydrogen, and little hydrocarbon generation potential remains. These findings led to the conclusion that the lowest of the existing resource estimates, namely 0.4x109 m3 (13 Tcf, may be the most realistic. However, such low estimates still represent a large resource with developmental potential for the South African petroleum industry. To be economically viable, the resource would be required to be confined to a small, well-delineated ‘sweet spot’ area in the vast southern area of the basin. It is acknowledged that the drill cores we investigated fall outside of currently identified sweet spots and these areas should be targets for further scientific drilling projects. Significance: This is the first report of direct measurements of the actual gas contents of southern Karoo basin shales. The findings reveal carbon content of shales to be dominated by overmature organic matter. The results demonstrate a much reduced potential shale gas resource presented by the Whitehill

A review of the stratigraphy and sedimentary environments of the Karoo-aged basins of Southern Africa

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Smith, R. M. H.; Eriksson, P. G.; Botha, W. J.

1993-02-01

The Karoo Basin of South Africa was one of several contemporaneous intracratonic basins in southwestern Gondwana that became active in the Permo-Carboniferous (280 Ma) and continued to accumulate sediments until the earliest Jurassic, 100 million years later. At their maximum areal extent, during the early Permian, these basins covered some 4.5 million km 2. The present outcrop area of Karoo rocks in southern Africa is about 300 000 km 2 with a maximum thickness of some 8000 m. The economic importance of these sediments lies in the vast reserves of coal within the Ecca Group rocks of northern and eastern Transvaal and Natal, South Africa. Large reserves of sandstone-hosted uranium and molybdenum have been proven within the Beaufort Group rocks of the southern Karoo trough, although they are not mineable in the present market conditions. Palaeoenvironmental analysis of the major stratigraphic units of the Karoo succession in South Africa demonstrates the changes in depositional style caused by regional and localized tectonism within the basin. These depocentres were influenced by a progressive aridification of climate which was primarily caused by the northward drift of southwestern Gondwana out of a polar climate and accentuated by the meteoric drying effect of the surrounding land masses. Changing palaeoenvironments clearly influenced the rate and direction of vertebrate evolution in southern Gondwana as evidenced by the numerous reptile fossils, including dinosaurs, which are found in the Karoo strata of South Africa, Lesotho, Namibia and Zimbabwe. During the Late Carboniferous the southern part of Gondwana migrated over the South Pole resulting in a major ice sheet over the early Karoo basin and surrounding highlands. Glacial sedimentation in upland valleys and on the lowland shelf resulted in the Dwyka Formation at the base of the Karoo Sequence. After glaciation, an extensive shallow sea covered the gently subsiding shelf, fed by large volumes of meltwater

Hydrochemical characteristics of aquifers near Sutherland in the Western Karoo, South Africa

CSIR Research Space (South Africa)

Adams, S

2001-01-15

Full Text Available management. Descriptive statistics, correlation matrices and factor analysis, together with stable isotope data were used to gain an understanding of the hydrochemical processes of the groundwaters in the fractured rocks around Sutherland in the Western Karoo...

Description of the Karoo Biome project

CSIR Research Space (South Africa)

Cowling, RM

1986-01-01

Full Text Available The ecological characteristics and ecological problems of the karoo biome are briefly described. A conceptual basis and guidelines for the development of the Karoo Biome Project are outlined by addressing project goals, project structure...

Changing palaeoenvironments and tetrapod populations in the Daptocephalus Assemblage Zone (Karoo Basin, South Africa) indicate early onset of the Permo-Triassic mass extinction

Science.gov (United States)

Viglietti, Pia A.; Smith, Roger M. H.; Rubidge, Bruce S.

2018-02-01

Important palaeoenvironmental differences are identified during deposition of the latest Permian Daptocephalus Assemblage Zone (DaAZ) of the South African Beaufort Group (Karoo Supergoup), which is also divided into a Lower and Upper subzone. A lacustrine floodplain facies association showing evidence for higher water tables and subaqueous conditions on the floodplains is present in Lower DaAZ. The change to well-drained floodplain facies association in the Upper DaAZ is coincident with a faunal turnover as evidenced by the last appearance of the dicynodont Dicynodon lacerticeps, the therocephalian Theriognathus microps, the cynodont Procynosuchus delaharpeae, and first appearance of the dicynodont Lystrosaurus maccaigi within the Ripplemead member. Considering the well documented 3-phased extinction of Karoo tetrapods during the Permo-Triassic Mass Extinction (PTME), the facies transition between the Lower and Upper DaAZ represents earlier than previously documented palaeoenvironmental changes associated with the onset of this major global biotic crisis.

Karoo fracking and the Christian faith community

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Gerrit van Tonder

2014-10-01

Full Text Available One of the challenges for Practical Theology in Africa is to engage with the continent’s concerns and challenges in such a way that the kingdom of God is realised in society and is seen to be relevant to these issues by people who are outside of academia. In our article, which was first presented at the Practical Theology congress in Pretoria in January 2014, the authors seek to demonstrate how this may be accomplished by applying insights to one concern, namely ‘fracking’. The objective is to mobilise the influential Christian faith community in South Africa to begin to exercise prophetic discernment concerning fracking in the Karoo. The fracking debate is a product of the tension between the environmental degradation that its waste products may cause, on the one hand, and, on the other, the greater energy demands of a rapidly increasing world population along with its expectations of an ever-increasing standard of living. Shale gas fracking in the Karoo region of South Africa promises to make vast reserves of oil and gas available to help meet a significant percentage of the country’s energy needs for many years to come, and so thus aid development and contribute to raising the standard of living of many people. Yet the management of the waste products associated with the process is an area of serious environmental concern. The article aims to apprise the South African Christian faith community of the technology and risks involved. Theological guidelines are presented by which fracking’s benefits and dangers can be interrogated so that the community may come to an informed decision as to whether or not to support fracking.

Permian storm current-produced offshore bars from an ancient shelf sequence : Northwestern Karoo basin, republic of South Africa

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Smith, A. M.; Zawada, P. K.

The Ecca-Beaufort transition zone from the Karoo Basin comprises upward-coarsening sequences which are interpreted as prograding, storm-produced offshore bars. Eight facies are recognised: (A) dark-grey shale, (B) thinly interbedded siltstone and mudstone, (C) thinly interbedded siltstone and very fine-grained sandstone, (D) blue-grey coarse-grained siltstone, (E) low-angle truncated and flat-laminated sandstone, (F) wave-rippled sandstone, (G) planar cross-bedded sandstone, (H) intraformational clay-pellet conglomerate. Four sub-environments are recognised, these being: (1) the bar crest which comprises proximal tempestites, (2) the bar slope consisting of soft-sediment deformed siltstone, (3) the bar fringe/ margin which is composed of storm layers and offshore siltstones and (4) the interbar/offshore environment comprising siltstone and distal storm layers. These bars formed in response to wave and storm processes and migrated across a muddy shelf environment. The orientation of bars was probably coast-parallel to subparallel with respect to the inferred north-northwest-south-southeast coastline. These proposed, storm-produced bars acted as major depo-centres within the shelf setting of the study area. As shelf sediments are recorded from almost the entire northwestern Karoo Basin it is anticipated that bar formation was an important sedimentary factor in the deposition of the sediments now referred to as the Ecca-Beaufort transition zone.

Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa

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Nicholas Fordyce

2012-10-01

Full Text Available Dicynodonts are an extinct group of herbivorous non-mammalian therapsids (‘mammal-like’ reptiles that are widely known from terrestrial Permo-Triassic strata throughout Pangaea. Dicynodont fossil remains are common within the Late Permian Beaufort Group of the Karoo Basin in South Africa. A large, partially articulated dicynodont skeleton recovered from the TropidostomaAssemblage Zone is taphonomically important in having an unusual disarticulation pattern, bone surface punctures and a broken tooth of an unidentified carnivore associated with it. Here we report on the nature of the bone damage, and the identity of the carnivore that lost a canine tooth whilst scavenging the dicynodont carcass. The morphological characteristics of the serrations on the unidentified tooth were compared with those of contemporaneous carnivores, the gorgonopsians and therocephalians. Scanning electron microscopy analysis of a silicone cast of the unidentified tooth revealed distinctive 0.5-mm square-shaped serrations. Our comparative assessment of the tooth size, curvature, cross-sectional shape and morphology of the serrations revealed that the unidentified canine most closely matched Aelurognathus,a gorgonopsian known from the same assemblage zone.

Ecology and distribution of large branchiopods (Crustacea, Branchiopoda, Anostraca, Notostraca, Laevicaudata, Spinicaudata of the Eastern Cape Karoo, South Africa

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Annah Mabidi

2016-09-01

Full Text Available A survey of the large branchiopod fauna of the Eastern Cape Karoo region of South Africa was undertaken to provide baseline biodiversity information in light of impending shale gas development activities in the region. Twenty-two waterbodies, including nine dams and thirteen natural depression wetlands, were sampled during November 2014 and April 2015. A total of 13 species belonging to four orders were collected, comprising five anostracans, one notostracan, six spinicaudatans and one laevicaudatan. Cyzicus australis was most common, occurring in 46% of the waterbodies. Species co-occurred in 87% of the waterbodies, with a maximum number of six species recorded from the same waterbody. Our new distribution records for Lynceus truncatus, Streptocephalus spinicaudatus and S. indistinctus represent substantial expansions of the previously known ranges for these species. Tarkastad is now the westernmost record for S. spinicaudatus, while Jansenville now constitutes the southernmost record for S. indistinctus. Large branchiopod distribution data from previous Eastern Cape records were combined with our current data, demonstrating that a total of 23 large branchiopod species have been recorded from the region to date. As the Karoo is one of the few major shale basins in the world where the natural baseline is still largely intact, this survey forms a basis for future reference and surface water quality monitoring during the process of shale gas exploration/extraction.

Long-term studies of land degradation in the Sneeuberg uplands, eastern Karoo, South Africa: A synthesis

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Boardman, J.; Foster, I. D. L.; Rowntree, K. M.; Favis-Mortlock, D. T.; Mol, L.; Suich, H.; Gaynor, D.

2017-05-01

For the past 15 yr, the Sneeuberg uplands in the eastern Karoo, South Africa, have been a focus for research on land degradation by the above authors and other colleagues. Earlier work in the Karoo emphasised vegetation change whereas we concentrate on physical changes to the landscape at the small catchment scale, e.g., bare, degraded areas (badlands) and gully (donga) systems. Analysis of sedimentation in farm dams allows for reconstruction of environmental histories using 210Pb, 137Cs, geochemical and mineral magnetic properties of the sediments. Erosion rates on badlands are monitored using arrays of erosion pins. Sediment source tracing within small catchments points to the importance of hillslope sources and the relative erosional inactivity of gully systems in recent decades. Sediment supply from hillslope and colluvial sources is maintained by high rates of weathering on mudstones and sandstones. Current degradation should be viewed in the context of a c. 200 yr history of overgrazing by European-style stock farming and limited areas of former cultivation in the valleys. Grazing pressures are now much reduced but the loss of soils and vegetation suggests that landscape recovery will require several decades. Additional drivers of past degradation are likely to have been periods of drought and fire (natural and managed) and a gradual increase in both rainfall intensity and the frequency of extreme rainfall events. The future of the degraded Sneeuberg landscape will depend on future farming practices. Desirable options include more sustainable livestock practices, adoption of wildlife farming and other more benign regimes involving mixes of agriculture, tourism, and wildlife protection together with landscape rehabilitation measures.

Nutrient selection by cattle, goats and sheep on natural Karoo ...

African Journals Online (AJOL)

Nutrient selection by cattle, goats and sheep on natural. Karoo pasture. 2. Nitrogen. P.J.L.Zeeman, P.G. Marais and M.J. Coetsee. Research Institute of the Karoo Region, Middelburg, Cape. The nitrogen (N) content of material selected by cattle, Boer goats,. Dorper and Merino sheep on natural Karoo pasture was ...

Refining the chronostratigraphy of the Karoo Basin, South Africa: magnetostratigraphic constraints support an early Permian age for the Ecca Group

Science.gov (United States)

Belica, Mercedes E.; Tohver, Eric; Poyatos-Moré, Miquel; Flint, Stephen; Parra-Avila, Luis A.; Lanci, Luca; Denyszyn, Steven; Pisarevsky, Sergei A.

2017-12-01

The Beaufort Group of the Karoo Basin, South Africa provides an important chrono- and biostratigraphic record of vertebrate turnovers that have been attributed to the end-Permian mass extinction events at ca. 252 and 260 Ma. However, an unresolved controversy exists over the age of the Beaufort Group due to a large data set of published U-Pb SHRIMP (Sensitive High Resolution Ion Microprobe) zircon results that indicate a ca. 274-250 Ma age range for deposition of the underlying Ecca Group. This age range requires the application of a highly diachronous sedimentation model to the Karoo Basin stratigraphy and is not supported by published palaeontologic and palynologic data. This study tested the strength of these U-Pb isotopic data sets using a magnetostratigraphic approach. Here, we present a composite ∼1500 m section through a large part of the Ecca Group from the Tanqua depocentre, located in the southwestern segment of the Karoo Basin. After the removal of two normal polarity overprints, a likely primary magnetic signal was isolated at temperatures above 450 °C. This section is restricted to a reverse polarity, indicating that it formed during the Kiaman Reverse Superchron (ca. 318-265 Ma), a distinctive magnetostratigraphic marker for early-middle Permian rocks. The Ecca Group has a corresponding palaeomagnetic pole at 40.8°S, 77.4°E (A95 = 5.5°). U-Pb SHRIMP ages on zircons are presented here for comparison with prior isotopic studies of the Ecca Group. A weighted mean U-Pb age of 269.5 ± 1.2 Ma was determined from a volcanic ash bed located in the uppermost Tierberg Formation sampled from the O + R1 research core. The age is interpreted here as a minimum constraint due to a proposed Pb-loss event that has likely influenced a number of published results. A comparison with the Geomagnetic Polarity Time Scale as well as published U-Pb TIMS ages from the overlying Beaufort Group supports a ca. 290-265 Ma age for deposition of the Ecca Group.

Klein Woordeboek / Little Dictionary | Louw | Lexikos

African Journals Online (AJOL)

Bilingual translation dictionaries play an important part in modern user orientated lexicography in South Africa. An affordable bidirectional pocket translation dictionary, such as Klein Woordeboek/Little Dictionary, with English and Afrikaans as language pair, is growing in value as a carrier of necessary everyday linguistic ...

Some variations in petrography of South African Karoo dolerites and the effects thereof on aggregate properties

CSIR Research Space (South Africa)

Leyland, R

2014-01-01

Full Text Available Supergroup, which is generally lacking in quality aggregate lithologies. The Karoo Dolerite Suite can however, despite being a single geological unit, be of significantly variable petrography mainly due to the very large area (>500,000 km2) and wide variety...

Karoo-fynbos biomass along an elevational gradient in the western Cape.

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M. C. Rutherford

1978-12-01

Full Text Available A short characterization of the vegetational gradient from two basic physiognomic forms of fynbos, through Renosterbosveld to arid Karoo vegetation of the south-western Cape, is given with reference to possible vegetational analogues within similar gradients in winter-rainfall areas elsewhere. Description is limited to some aspects affecting biomass and its measurement, as well as to consideration of community stability needed for valid comparison of community biomass. Live individuals, including single dominant species, all other shrubs, graminoids and other herbaceous species as well as dead individuals were harvested separately in each major community type within an elevational gradient corresponding to the vegetational gradient described. Greatest biomass (14311 kg ha-1 was found in a summit restionaceous community, while lowest biomass (7564 kg ha-1 was found in a low-lying succulent Karoo community. There was an inverse relationship between elevation and percentage dead material mass and a strongly positive relationship between elevation and percentage biomass of the graminoid group. Total biomass values appear to be in keeping with available data for analogue communities in different Mediterranean climate areas, although distinct differences sometimes occur in the relative biomass contributions of component groups.

A fluvioglacial and gaciolacustrine deltaic depositional model for Permo-Carboniferous coals of the northeastern Karoo Basin, South Africa

Energy Technology Data Exchange (ETDEWEB)

Smith G, Le Blanc; Eriksson, K A

1979-01-01

With the northward retreat of the late Palaeozoic Gondwana ice sheet a series of glacial valleys, partially filled with diamictite, dominated the landscape along the northern edge of the Karoo basin in South Africa. Consequent outwash sediments accumulated as fluvioglacial and glaciolacustrine deltaic deposits. Density underflow generated turbidity currents from which bottomset sediments were deposited. These comprise distal varved siltstones and shales, stratified pebbly-mudstone with dropstones, and proximal ripple drift cross-laminated sandstones and siltstones. Overlying outwash plain conglomerates and sandstones constitute the topset deposits. Upon abandonment of the outwash plain, shallow-rooted Arctic vegetation developed. Resulting peats exceeded 10 m in thickness and constituted precursors to coal seams in which variations in ash content are attributed to overbank splaying from recognisable anastomosing channels within the coal swamps. This study has illustrated a characteristic paraglacial sedimentation sequence, maximum depositional rates occur immediately after glacial retreat followed by decelerating sedimentation rates through time, leading finally to the development of extensive peats. (29 refs.)

The Karoo fracking debate: a christian contribution to the world communities of faith.

Science.gov (United States)

Tucker, A Roger; van Tonder, Gerrit

2015-06-01

The fracking debate is a product of the tension between the environmental degradation it may cause, on the one hand, and on the other the greater energy demands of a rapidly increasing South African population with expectations of an ever-increasing standard of living. Shale gas fracking in the Karoo of South Africa promises to make vast reserves of oil and gas available to help meet a significant percentage of the country's energy needs for many years to come. This will aid development and contribute to raising the standard of living of many. This article seeks to apprise the South African faith communities of the technology and risks involved. Christian theological guidelines are presented by which its benefits and dangers may be interrogated so that the community may be able come to an informed decision as to whether or not to support fracking.

A new approach to biostratigraphy in the Karoo retroarc foreland system: Utilising restricted-range palynomorphs and their first appearance datums for correlation

Science.gov (United States)

Barbolini, Natasha; Rubidge, Bruce; Bamford, Marion K.

2018-04-01

The main Karoo Basin (MKB), internationally renowned for its wealth of fossil tetrapods, has been lithostratigraphically subdivided into three discrete regions: two (east and west) proximal facies adjacent to the Cape Fold Belt, and a distal facies, away from the Cape Fold Belt. Because of lithological differences between formations of the proximal and distal sectors of the MKB, it has been difficult to correlate time-equivalent lithostratigraphic units in the different sectors. Palynology provides a tool for refining stratigraphic correlations within the MKB, but only species with restricted ranges are biostratigraphically significant. Restricted-range palynomorph taxa from the Ecca and Beaufort groups indicate the following relationships: the lowermost Vryheid Formation palynoflora can be strongly correlated with that of the Prince Albert Formation, whereas the Whitehill-Collingham formations and No. 2 seam (Vryheid Formation), and the Ripon Formation and No. 4 seam (Vryheid Formation) can be tentatively linked using palynology. The lower-middle Normandien Formation in the north is chronologically equivalent to the Ripplemead member of the Balfour Formation in the south. Although the Ecca-Beaufort Group boundary is known to be diachronous, restricted-range palynomorphs cannot yet confirm that the uppermost Ecca Group in the northern part of the basin was deposited at the same time as the lower Beaufort Group in the south. This study demonstrates that despite diachronous ranges of some taxa, palynology is useful in correlating age-equivalent lithostratigraphic units in the proximal and distal sectors of the basin. A new First Appearance Datum (FAD) palynozonation for the Karoo is presented that is calibrated by the most recent radiometric dates for South Africa, Australia, and South America. The new zones are also correlated with Permian successions in Antarctica, Zambia, Botswana, and India. Future palynostratigraphic work in South Africa must take into account

Sedimentology and palaeontology of upper Karoo aeolian strata (Early Jurassic) in the Tuli Basin, South Africa

Science.gov (United States)

Bordy, Emese M.; Catuneanu, Octavian

2002-08-01

The Karoo Supergroup in the Tuli Basin (South Africa) consists of a sedimentary sequence composed of four stratigraphic units, namely the Basal, Middle and Upper units, and Clarens Formation. The units were deposited in continental settings from approximately Late Carboniferous to Middle Jurassic. This paper focuses on the Clarens Formation, which was examined in terms of sedimentary facies and palaeo-environments based on evidence provided by primary sedimentary structures, palaeo-flow measurements and palaeontological findings. Two main facies associations have been identified: (i) massive and large-scale planar cross-bedded sandstones of aeolian origin; and (ii) horizontally and cross-stratified sandstones of fluvial origin. Most of the sandstone lithofacies of the Clarens Formation were generated as transverse aeolian dunes produced by northwesterly winds in a relatively wet erg milieu. Direct evidence of aquatic subenvironments comes from local small ephemeral stream deposits, whereas palaeontological data provide indirect evidence. Fossils of the Clarens Formation include petrified logs of Agathoxylon sp. wood type and several trace fossils which were produced by insects and vertebrates. The upper part of the Clarens Formation lacks both direct and indirect evidence of aquatic conditions, and this suggests aridification that led to the dominance of dry sand sea conditions.

[Jan Kusberg, Kleine Geschichte St. Petersburgs. (Regensburg, 2009) ; Ingrid Bohn. Kleine Geschichte Stockholms. (Regensburg, 2008) ; Konrad Dittrich. Kleine Lübecker Stadtgeschichte. (Regensburg, 2007)] / Dennis Hortmuth

Index Scriptorium Estoniae

Hormuth, Dennis

2011-01-01

Arvustus: Jan Kusberg, Kleine Geschichte St. Petersburgs. (Regensburg, 2009) ; Ingrid Bohn. Kleine Geschichte Stockholms. (Regensburg, 2008) ; Konrad Dittrich. Kleine Lübecker Stadtgeschichte. (Regensburg, 2007)

Comparison of total and cold-extractable uranium in stream sediments of the southwestern Karoo supergroup, South Africa

International Nuclear Information System (INIS)

Jakob, W.R.O.; Smit, M.C.B.; Murphy, G.C.

1979-01-01

In order to evaluate the usefullness of cold-extractable uranium as a tool of uranium prospecting in stream sediments of the southwestern Karoo, South Africa, ten orientation studies were conducted near known mineralisation jointly by the Atomic Energy Board and the Geological Survey of South Africa. These indicate that the topography determines the nature of the dispersion. In areas of moderate to high relief the total uranium content of the stream sediment gives dispersion trains up to about 500 m from the mineralisation, and peak-to-background ratios of about 3. The use of cold-extractable uranium doubles the length of the dispersion, and peak-to-background ratios are greater than 10 and may be as high as 35. In areas of low relief, the total uranium content of the sediment gives low anomalies, with short dispersion downstream. Cold-extractable uranium gives anomalies 500-1 000 m from the mineralisation. This is interpreted to be due to the longer residence time of the clay minerals in the stream. In order to test the applicability of cold-extractable uranium on a regional scale, 720 samples were collected at a density of one sample per square kilometre. Statistical treatment of the data shows the U content of the stream sediments, to be log-normally distributed. For cold-extractable uranium, polymodal distributions, apparently representing background and anomalous samples, can be separated with a high rate of success, and meaningful threshold values can be assigned. This is not the case for the total uranium content of the stream sediments [af

The truth is in the isotopes: Authenticating regionally unique South African lamb.

Science.gov (United States)

Erasmus, Sara W; Muller, Magdalena; Butler, Mike; Hoffman, Louwrens C

2018-01-15

Stable isotope ratios ( 13 C/ 12 C and 15 N/ 14 N) of South African lambs from different regions were measured by isotope ratio mass spectrometry (IRMS). Homogenised and defatted meat of the Longissimus lumborum muscle was assessed. The Rûens and Hantam Karoo regions had the lowest (P≤0.05) δ 13 C values related to the presence of C 3 plants (lucerne and Karoo bushes, respectively). The Northern Karoo, Namibia and Bushmanland had the highest δ 13 C values likely due to a high proportion of dietary C 4 grass species. The δ 15 N values were highest for Central Karoo, Semi-extensive, Namibia and Hantam Karoo, while Rûens and Feedlot had the lowest nitrogen isotope values (P≤0.05). Classification of origin (Karoo vs. Non-Karoo) using discriminant analysis allowed 95% and 90% correct classification of the samples for the estimation model and validation models, respectively. The results confirm that IRMS provides sufficient discriminative power to classify lamb meat of varying origin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using Sentinel-2A multispectral imagery to explore for deep groundwater resources in the Ceres-Tankwa Karoo, Western Cape, South Africa: Significance for the 'water-energy(-food) nexus' in an arid region

Science.gov (United States)

Hartnady, Chris; Wise, Edward; Hartnady, Michael; Olianti, Camille; Hay, E. Rowena

2017-04-01

The Ceres-Tankwa region is an arid region in the south-western part of the main Karoo Basin, underlain by folded and faulted strata of the Cape and lower Karoo Supergroups in the syntaxis zone between the Western and Southern branches of the Cape Fold Belt. Explored for oil in the mid-1960s, with the drilling of the >3000 m deep KL1/65 borehole, the area recently attracted attention as a potential shale-gas prospect with the drilling in 2015 of the 671 m-deep KZF-1 research borehole on the farm Zandfontein (de Kock et al, 2016). KZF-1 encountered no positive indication of methane gas in the carbonaceous shale target but intersected a strong flow of deep groundwater from fractures in the basal Dwyka tillite. The accidental discovery of deep artesian groundwater, probably originating from the underlying Cape Supergroup aquifers and of significantly better quality than the shallow aquifer utilised by local farmers, has important implications for future development here. Using 13-channel multispectral data from the European Space Agency satellite Sentinel-2A, a false-colour composite image, centred about the KZF-1 location, was assembled by combination of selected spectral band-ratios. Stratigraphic layering and associated folding within the hitherto undivided, pelitic Tierberg Formation (Ecca Group), is revealed in striking new detail, together with narrow lines of stratal offset corresponding to previously unmapped faults. KZF-1 is evidently sited within an anomalous NE/SW-striking belt, unlike the general NNW/SSE strike of Cape-Karoo sequence strata in the north-western part of the image. Associated with a notable strike change of a lower Tierberg marker unit, subparallel to and aligned with a similar trend in the Swartruggens mountain foothills to the SW, a deep-seated, controlling, NE/SW-striking fault structure may continue downwards from the lower Karoo units into the underlying Cape strata, providing hydraulic connection. With the looming threat of global

Kleine-Levin syndrome as a neuropsychiatric presentation: A case ...

African Journals Online (AJOL)

2014-07-02

Jul 2, 2014 ... describes a case of typical KLS, the first to be documented in South. Africa (SA), and ... re admitted with a second episode of aggression, hypersomnia, headaches .... of KLS, Arnulf et al. ... Neurol 2010;13(4):241-246. ... Muratori F, Bertini N, Masi G. Efficacy of lithium treatment in Kleine-Levin syndrome. Eur.

Stratigraphy and sediment provenance of the Karoo Supergroup in Southern Botswana using geochemical indicators

Science.gov (United States)

Diskin, Sorcha; Wendorff, Marek; Lasarwe, Reneilwe

2010-05-01

The Karoo Supergroup of Botswana unconformably overlies Archaean and Proterozoic rocks. They are however, poorly exposed being in turn overlain by up to 200m of Kalahari Beds. This Carboniferous - Jurassic succession comprises sequences of sedimentary and volcanic rocks which are spread across southern Africa. In Botswana, rock complexes have been correlated between widely spaced boreholes based on macroscopically similar appearance and similar position in the succession. In neighbouring South Africa and Namibia these rocks are well exposed and the lithostratigraphy is well constrained by the fossil record. The Karoo units of Botswana have been correlated with these more precisely defined successions on the basis of lithostratigraphy only and are unsupported by other criteria and as such are limited; especially considering the different depositional settings between Botswana and South Africa. Here we present the results of a study of the heavy whole rock geochemistry in an attempt to provide additional, chemostratigraphic criteria for the lower and middle part of the Karoo suite, the Dwyka and Ecca Groups. Analysis of 60 samples for major and trace (including REE) element composition shows a close relation between the geochemical characteristics and stratigraphy. Major elements show that the deltaic material of the Kweneng Formation and Boritse Formation was sourced from recycled continental crust. The basinal mudstone and siltstone below and above fall into an intermediate-mafic igneous field. Most samples have distinct negative europium anomalies (Eu/Eu*=0.49-1.27; av. = 0. 75) and most values are characteristic of sediments of cratonic derivation. A clear shift in (Gd/Yb)N in the basinal pro-delta shales (the Bori Formation) is generally 2.0 or greater, which is typical of an Archean signature, whereas post-Archean rocks usually have (Gd/Yb)N 1.0 - 2.0 as seen for the strata above the delta mouth bars and channels (average 1.6). In a diagram in which (La

Magnetostratigraphy of the Naude's Nek Section (Karoo Traps): News Constraints on the Eruptive Sequence

Science.gov (United States)

Moulin, M.; Jay, A. E.; Fluteau, F.; Marsh, J. S.; Courtillot, V.; Gerard, M.; Quidelleur, X.

2008-12-01

A causal relationship between large igneous provinces (LIP) and mass extinctions (ME) or oceanic anoxia events (OAE) is supported by an increasing data base of age determinations. Although the impact of recent (much smaller) volcanic eruptions on climate is understood as being largely due to injection of SO2 into the stratosphere, the environmental effects of LIP eruptions remain ill understood. Successful climate modelling requires high-resolution timing of volcanism, i.e. number, volume and duration of peak episodes. Chenet et al (2008, and in revision) have studied the Deccan traps, which correlate with the major KT crisis, combining geochronology (K-Ar), paleomagnetism (secular variation), volcanology (flow types) and analysis of alteration levels between flows (red boles); they have shown that emplacement occurred as a small number of discrete, very large and short-lived pulses (see Courtillot et al, same session). But mass extinctions are not all alike, in pattern or intensity. Some large igneous provinces are correlated with only minor crises, e.g. the Karoo traps formed near the Pliensbachian-Toarcian boundary (~180 Ma). Remnants of these traps outcrop over >2.5×106 km2. Jourdan et al. (2008) find that the Karoo traps were emplaced over some 4 Myr, significantly longer than the Deccan. However, the Karoo province does seem to comprise brief (traps), located in South Africa near the southern border of Lesotho. Our first determinations (40K-40Ar Cassignol-Gillot technique) yield ages of 180±1.8 Ma, in good agreement with previous studies. Detailed flow by flow magnetostratigraphy (site-mean directions based on thermal demagnetization) shows that the eruptive sequence can be divided into several volcanic pulses having likely lasted less than ~100 years. We have obtained a particularly detailed record of the only reversal found in the sequence and identified by van Zijl 50 years ago: 136 m of lava erupted over less than a few thousand years. Although our

Paleomagnetism and Magnetostratigraphy of Upper Permian to Lower Triassic (?) Beaufort Group Strata at Bethulie, Karoo Basin, Free State Province, South Africa

Science.gov (United States)

Geissman, J. W.; Gastaldo, R. A.; Neveling, J.; Makubalo, S.

2017-12-01

A multifaceted approach to understand the timing of interpreted environmental changes during the Late Permian to possibly Early Triassic (?) time in the Beaufort Group strata of the Karoo Basin includes work to establish robust magnetic polarity records for sections previously interpreted to encompass end-Permian extinction events. Demonstrating the preservation of an early-acquired remanence (RM) in Karoo strata is required for a robust magnetostratigraphy. Yet, this is challenging due to thermochemical effects related to the Early Jurassic (ca. 183 Ma) Karoo Large Igneous Province (LIP), and the NE to SW increase in burial diagenesis attending Cape Fold Belt tectonism. Documentation of a primary RM in these strata, which appears to be preserved in some areas, requires careful laboratory- and field-based assessment. We report data from 53 sites collected at the well-studied Bethulie section, Free State Province, in which several samples per individual horizon to assess ChRM uniformity. Strata well-removed from dikes yield both normal and reverse polarity ChRM. It is always the case that the first-removed RM is a NNW seeking, moderate to steep negative-inclination ChRM (normal polarity); NRM intensities are typically 1 to 5 mA/m. Sites BT15 and BT21, which are located in strata lying some 4 m below the often-cited "event bed" interval inferred to be the terrestrial expression of the Permian/Triassic boundary, is dominated by a well-defined reverse RM with a normal overprint RM unblocked below 400oC, implying elevated temperatures (i.e., 100 to 250oC+) for ca. 1 Ma (+/-). Contact tests are positive but complicated. Host strata collected in distances equal to or less than 1-2 dike widths from the intrusions have been thermally remagnetized and demonstrate high NRM intensities (> 50 mA/m). Collectively, we interpret these data to indicate that any ChRM, with the exception of those from host strata in baked contacts, that persists above Tlub of 425oC is pre-Karoo LIP

Stability of squashed Kaluza-Klein black holes

International Nuclear Information System (INIS)

Kimura, Masashi; Ishihara, Hideki; Murata, Keiju; Soda, Jiro

2008-01-01

The stability of squashed Kaluza-Klein black holes is studied. The squashed Kaluza-Klein black hole looks like a five-dimensional black hole in the vicinity of horizon and looks like a four-dimensional Minkowski spacetime with a circle at infinity. In this sense, squashed Kaluza-Klein black holes can be regarded as black holes in the Kaluza-Klein spacetimes. Using the symmetry of squashed Kaluza-Klein black holes, SU(2)xU(1)≅U(2), we obtain master equations for a part of the metric perturbations relevant to the stability. The analysis based on the master equations gives strong evidence for the stability of squashed Kaluza-Klein black holes. Hence, the squashed Kaluza-Klein black holes deserve to be taken seriously as realistic black holes in the Kaluza-Klein spacetime.

A comparative study of detrital zircon ages from river sediment and rocks of the Karoo Supergroup (Late Carboniferous to Jurassic), Eastern Cape Province, South Africa : implications for the tectono-sedimentary evolution of Gondwanaland’s southern continental margin

OpenAIRE

2014-01-01

M.Sc. (Geology) The Mzimvubu River, situated in the Eastern Cape Province of South Africa, drains essentially strata of the Late Carboniferous to Jurassic Karoo Supergroup with minor intersection of the underlying Devonian Msikaba Formation near the mouth of the river at Port St. Johns. Rock- and river sediment samples were collected at specific points from within the Mzimvubu River drainage basin, based on changes in the geology through which the rivers flow. Detrital zircon age populatio...

Erna and Melanie Klein.

Science.gov (United States)

Tabak de Bianchedi, Elizabeth; Etchegoyen, R Horacio; Ungar de Moreno, Virginia; Nemas de Urman, Clara; Zysman, Samuel

2003-12-01

Erna was one of the child patients treated by Melanie Klein in Berlin, employing her recently discovered play technique. Since Erna died in Chile, the authors considered the IPA Congress in Santiago an opportunity to present a paper as a homage both to Erna and, especially, to Klein. She learned much from that very disturbed child, which she later used to sustain the ongoing development of her theories. The paper explores biographic data relevant to understanding both the case and the theories. It analyses the case material to follow Klein in the discovery and the handling of the child's transference and the harsh expressions of hate, jealousy and envy, which are brought in, with sad consequences, by strong persecutory feelings. Klein's comparison of this case with that of Freud's Wolf-man is also considered, mostly to show that the similarities were less than originally claimed, and that Klein, perhaps, was introducing a theoretic shift which led her technique to gradually change from 'Nachträglichkeit' to the 'signification-resignification' pair, akin to Strachey's concept of the mutative interpretation. Lastly, the comprehension of Erna's strong psychotic traits and the links with later developments of the theory on psychosis are studied.

The Klein-Gordon Operator on Möbius Strip Domains and the Klein Bottle in ℝn

International Nuclear Information System (INIS)

Kraußhar, Rolf Sören

2013-01-01

In this paper we present explicit formulas for the fundamental solution to the Klein-Gordon operator on some higher dimensional generalizations of the Möbius strip and the Klein bottle with values in distinct pinor bundles. The fundamental solution is described in terms of generalizations of the Weierstrass ℘ -function that are adapted to the context of these geometries. The explicit formulas for the kernel then allow us to express all solutions to the homogeneous and inhomogeneous Klein-Gordon problem with given boundary data in the context of these manifolds. In the case of the Klein bottle we are able to describe all null solutions of the Klein-Gordon equation in terms of finite linear combinations of the fundamental solution and its partial derivatives

Uranium prospecting in the main Karoo basin in retrospect: V. 1

International Nuclear Information System (INIS)

Van der Merwe, P.J.

1986-12-01

Prospecting for sandstone-hosted uranium deposits in the Main Karoo Basin started in 1969 and ceased during 1985. Although some farms are still under option, no further exploration in the short term is envisaged. Uranium deposits were located in sediments of the Lower Beaufort Group, and Elliot and Molteno Formations of the Stormberg Group. Reasonable Assured and Estimated Additional Resources recoverable at less than $130/kg U amount to 31 211 t U. The Southern Karoo region has the largest share with 93 % of the resources. The 4 major orebodies east of Beaufort West, i.e. Rystkuil and its extensions, Haanekuil, Kareepoort and De Pannen contain 50 % of the Southern Karoo's resources. These four deposits also contain 60 % of the molybdenum resources, and constitute the single most viable mining district in the Main Karoo Basin. The economic viability of the four orebodies mentioned above was investigated and, at a uranium price of R78,05/kg U and a molybdenum price of R13,08/kg Mo in 1985 money terms, the DCFROR yield is 16,3 % after tax. These deposits have a life of 20 years at an annual production rate of 800 t uranium and approximately 600 t molybdenum. The molybdenum production is sufficient to supply the country's current needs. Taking cognisance of the fact 89 % of the revenue is generated by uranium and the current oversupply of uranium on the world markets, it is unlikely that these deposits would be exploited in the short to medium term, unless an urgent need for a domestic molybdenum source arises

Instability of the Kaluza-Klein vacuum

International Nuclear Information System (INIS)

Witten, E.

1982-01-01

It is argued that the ground state of the Kaluza-Klein unified theory is unstable against a process of semiclassical barrier penetration. This is related to the fact that the positive energy conjecture does not hold for the Kaluza-Klein theory; an explicit counter-example is given. The reasoning presented here assumes that in general relativity one should include manifolds of non-vacuum topology. It is argued that the existence of elementary fermions (not present in the original Kaluza-Klein theory) would stabilize the Kaluza-Klein vacuum. (orig.)

Possible trace fossils of putative termite origin in the Lower Jurassic (Karoo Supergroup) of South Africa and Lesotho

OpenAIRE

Bordy, E.M.; Bumby, A.J.; Catuneanu, O.; Eriksson, P.G.

2009-01-01

Complex structures in the sandstones of the Lower Jurassic aeolian Clarens Formation (Karoo Supergroup) are found at numerous localities throughout southern Africa, and can be assigned to five distinct architectural groups: (1) up to 3.3-m high, free-standing, slab-shaped forms of bioturbated sandstones with elliptical bases, orientated buttresses and an interconnecting large burrow system; (2) up to 1.2-m high, free-standing, irregular forms of bioturbated sandstones with 2-cm to 4-cm thick,...

Linking ecosystem services and water resources: landscape-scale hydrology of the Little Karoo

CSIR Research Space (South Africa)

Le Maitre, David C

2007-07-01

Full Text Available with a dense biological soil crust (biocrust) formed by cyanobacteria, lichens, and mosses (Esler et al. 2006). The dwarf (< 50 cm tall) Karoo shrub- land is rich in endemic succulents, particularly Aizoaceae and Crassulaceae. Slightly raised, more...% moderately degraded (Table 1; Thompson et al. 2005). River floodplains have been severely affected, with 51% of all lower river reaches (Vlok et al. 2005) being severely degraded and only 11% in good condition. Less than 2% of the area of succulent Karoo...

Klein-Gordon oscillators in noncommutative phase space

International Nuclear Information System (INIS)

Wang Jianhua

2008-01-01

We study the Klein-Gordon oscillators in non-commutative (NC) phase space. We find that the Klein-Gordon oscillators in NC space and NC phase-space have a similar behaviour to the dynamics of a particle in commutative space moving in a uniform magnetic field. By solving the Klein-Gordon equation in NC phase space, we obtain the energy levels of the Klein-Gordon oscillators, where the additional terms related to the space-space and momentum-momentum non-commutativity are given explicitly. (authors)

Game farming as a supplementary farming activity in the Karoo ...

African Journals Online (AJOL)

Game farming as a supplementary farming activity in the Karoo. ... Veld management in a game farming situation poses problems due to the ineffectiveness of rotational grazing systems. Simplification of natural ... AJOL African Journals Online.

The structure of the Okavango giant mafic dyke swarm in the Karoo magmatic province of North Botswana

Science.gov (United States)

Le Gall, B.; Tshoso, G.; Tiercelin, J. J.; Dyment, J.; Aubourg, C.; Feraud, G.; Jourdan, F.; Bertrand, H.

2003-04-01

Field structural measurements combined to magnetic dataset (including both aero- and ground magnetic records) allow a systematic investigation of the structure of the Okavango giant (2000 x 100 km) mafic dyke swarm in N Botswana. The results are discussed about a 55 km-long projected section lying perpendicular to the densest zone of the swarm and cutting through Proterozoic granito-gneissic host-rocks. A total dyke population of 423 (magnetic records) or 171 (field data) individual intrusions is identified and consists principally of basalts and dolerites. New high-precision dating (Jourdan et al., this congress) demonstrates the composite nature of the Okavango swarm that includes Karoo dykes (70%) and additional (30%) Proterozoic intrusions. The two dyke populations lie with a similar strike and show no discriminant petro-structural features in the field. These new results make it difficult 1) discriminating Karoo versus Proterozoic dyke groups within the total population derived from magnetics, and 2) defining their respective structural characteristics. About the Karoo dyke population (360 intrusions), field structural observations help to constrain the statistical analysis of some of its geometrical parameters, such as the strike (N110°E), dip (vertical), lenght (ca. 5 km), thickness (18-20 m), spacing, or direction of dyke opening. The dyke-induced crustal dilatation is estimated to 6-10% across the 55 km-long reference section. Structural observations also emphazise the control exerted by preexisting basement fabrics (brittle joints and dykes) on Karoo dyke emplacement. Synmagmatic deformation is restricted to wall-parallel tensile joint networks with no evidence for extensional faulting. The Karoo part of the Okavango giant dyke swam is inferred to have been emplaced under an unidirectional extensional stress field (N70°E). Furthermore, analyzing the anisotropy of magnetic susceptibility of a number of dykes (Tshoso et al., this congress) indicates an

Will a decreasing winter rainfall cause a shift in Succulent Karoo boundaries? Evidence from competition and vegetation-change analyses.

CSIR Research Space (South Africa)

Shiponeni, NN

2008-09-01

Full Text Available The ecotone between the Namaqualand shrublands (Succulent Karoo biome) and Bushmanland Arid Grassland (Nama-Karoo biome) is characterised by transitional (ecotonal) physiognomy (grassland-shrubland mosaic, and grass and shrubs intermingling in arid...

Constraining the sedimentology and stratigraphy of submarine intraslope lobe deposits using exhumed examples from the Karoo Basin, South Africa

Science.gov (United States)

Spychala, Y. T.; Hodgson, D. M.; Flint, S. S.; Mountney, N. P.

2015-06-01

Intraslope lobe deposits provide a process record of the infill of accommodation on submarine slopes and their recognition enables the accurate reconstruction of the stratigraphic evolution of submarine slope systems. Extensive exposures of discrete sand-prone packages in Units D/E and E, Fort Brown Formation, Karoo Basin, South Africa, permit analysis of the sedimentology and stacking patterns of three intraslope lobe complexes and their palaeogeographic reconstruction via bed-scale analysis and physical correlation of key stratal surfaces. The sand-prone packages comprise tabular, aggradationally to slightly compensationally stacked lobe deposits with constituent facies associations that can be attributed to lobe axis, lobe off-axis, lobe-fringe and distal lobe-fringe environments. Locally, intraslope lobe deposits are incised by low aspect ratio channels that mark basinward progradation of the deepwater system. The origin of accommodation on the slope for lobe deposition is interpreted to be due to differential compaction or healing of scars from mass wasting processes. The stacking patterns and sedimentary facies arrangement identified in this study are distinct from those of more commonly recognized basin-floor lobe deposits, thereby enabling the establishment of recognition criteria for intraslope lobe deposits in other less well exposed and studied fine-grained systems. Compared to basin floor lobes, intraslope lobes are smaller in volume, influenced by higher degrees of confinement, and tend to show aggradational stacking patterns.

Reassessing the clinical affinity between Melanie Klein and D.W. Winnicott (1935-51): Klein's unpublished "Notes on baby" in historical context.

Science.gov (United States)

Aguayo, Joseph

2002-10-01

The author investigates the clinical affinity between Klein and Winnicott (1935-46) asa way to historically situate Winnicott 's later criticism of Klein's 'temperamental' inability to understand the impact of the environment on the infant's development. By setting out Klein s theories at the time when Winnicott began supervision with her in 1935, a context is established for the analysis of an unpublished 1937 manuscript by Klein ('Notes on baby'). The author argues that this direct and extensive infant observation demonstrates Klein's sensitivity to the familial environment. While Winnicott as a paediatrician showed enthusiasm for Klein s ideas, he also demonstrated a difference of opinion in emphasising the maternal environment of provision after his wartime evacuation experiences with London children. The factors leading to their mutual distancing are outlined as follows: (1) the post-Controversial Discussion atmosphere of the British Psycho-Analytical Society in 1944. The new non-aligned psychoanalytic 'middle group' allowed Winnicott to take a pick and choose attitude towards available analytic theories; (2) Winnicott us new clinical practices and theory differed from Klein 's, leading to a widening gap between 1946 and 1951. Winnicott's new theory and practice simultaneously represented his technical marginalisation of Klein s emphasis on the direct analysis of the patient s destructiveness by the time he delivered the 'Transitional objects' paper in 1951.

Hydrocarbon-Rich Groundwater above Shale-Gas Formations: A Karoo Basin Case Study.

Science.gov (United States)

Eymold, William K; Swana, Kelley; Moore, Myles T; Whyte, Colin J; Harkness, Jennifer S; Talma, Siep; Murray, Ricky; Moortgat, Joachim B; Miller, Jodie; Vengosh, Avner; Darrah, Thomas H

2018-03-01

Horizontal drilling and hydraulic fracturing have enhanced unconventional hydrocarbon recovery but raised environmental concerns related to water quality. Because most basins targeted for shale-gas development in the USA have histories of both active and legacy petroleum extraction, confusion about the hydrogeological context of naturally occurring methane in shallow aquifers overlying shales remains. The Karoo Basin, located in South Africa, provides a near-pristine setting to evaluate these processes, without a history of conventional or unconventional energy extraction. We conducted a comprehensive pre-industrial evaluation of water quality and gas geochemistry in 22 groundwater samples across the Karoo Basin, including dissolved ions, water isotopes, hydrocarbon molecular and isotopic composition, and noble gases. Methane-rich samples were associated with high-salinity, NaCl-type groundwater and elevated levels of ethane, 4 He, and other noble gases produced by radioactive decay. This endmember displayed less negative δ 13 C-CH 4 and evidence of mixing between thermogenic natural gases and hydrogenotrophic methane. Atmospheric noble gases in the methane-rich samples record a history of fractionation during gas-phase migration from source rocks to shallow aquifers. Conversely, methane-poor samples have a paucity of ethane and 4 He, near saturation levels of atmospheric noble gases, and more negative δ 13 C-CH 4 ; methane in these samples is biogenic and produced by a mixture of hydrogenotrophic and acetoclastic sources. These geochemical observations are consistent with other basins targeted for unconventional energy extraction in the USA and contribute to a growing data base of naturally occurring methane in shallow aquifers globally, which provide a framework for evaluating environmental concerns related to unconventional energy development (e.g., stray gas). © 2018, National Ground Water Association.

The Robertson Karoo as pastural area | JGV | African Journal of ...

African Journals Online (AJOL)

In the Robertson Karoo eight plant communities can he distinguished. Quantitative plant surveys were conducted in all the communities. Succulents form an important component of the vegetation. The plant communities are very stable after invasion by succulents which tend to remain dominant more or less permanently.

Towards a plant-based technique to measure utilization of Karoo ...

African Journals Online (AJOL)

The sparseness of Karoo veld renders the destructive sampling of areas less efficient than clipping individual plants. However, sampling of whole plants and their separation into edible and inedible fractions is laborious and expensive. There is thus a need to develop suitable non-destructive techniques.Language: English.

Kleine-Levin Syndrome

Science.gov (United States)

... About Research NINDS supports a broad range of clinical and basic research on diseases causing sleep disorders in an effort to clarify the mechanisms of these ... Publications Definition Kleine- ...

Palynology of Sub-Saharan Karoo Basins: Key to Early Mesozoic palaeoclimate reconstruction

Science.gov (United States)

Götz, Annette E.

2014-05-01

Palynological data of Permian-Triassic formations of the Sub-Saharan Karoo basins play a crucial role in the study and for the understanding of Gondwana's climate history and biodiversity in this time of major global changes in terrestrial and marine ecosystems. The palynological record reflects changes in land plant communities and vegetational patterns related to climate change and thus provides significant data for high-resolution palaeoclimate reconstructions in deep time. Recent palynological investigations of Triassic successions of South Africa, Mozambique and Tanzania document major changes in palaeoclimate. The spore/pollen ratios are used as a proxy for humidity changes. Stratal variations in the composition of the pollen group indicate warming and cooling phases. Variations in the amount and in the type, size and shape of phytoclasts reflect short-term changes in transport and weathering. The detected palaeoclimate signals are used for high-resolution correlation on basin-wide, intercontinental and intra-Gondwanic scales.

The karoo biome: a preliminary synthesis. Part 2- vegetation and history

CSIR Research Space (South Africa)

Cowling, RM

1987-01-01

Full Text Available between soil ulinity d the incidence of succulence has already been amtioned. In the eastern Karoo the incidence of stem succulence is positively correlated with levels of soil phosphorus, potassium, calcium and magnesium (M T Hoffman unpublished...

Increasing salinity drastically reduces hatching success of crustaceans from depression wetlands of the semi-arid Eastern Cape Karoo region, South Africa.

Science.gov (United States)

Mabidi, Annah; Bird, Matthew S; Perissinotto, Renzo

2018-04-13

Salinity is an important factor affecting freshwater aquatic species distribution and diversity. The semi-arid Eastern Cape Karoo region of South Africa has been earmarked for shale gas development through hydraulic fracturing. The process uses large amounts of water and produces briny wastewater. When not managed properly, these wastewaters may lead to salinisation of surface freshwater bodies in the region. Therefore, the effect of salinity on the hatching success of crustacean resting eggs was examined using sediments from four depression wetlands found in the region. The sediments were exposed for 28 days to salinity levels of 0.5 g L -1 , 2.5 g L -1 , 5 g L -1 and 10 g L -1 . Control aquaria in which no salt was added were also set up. There was a significant decrease in the emerged taxa richness and abundances at salinities of 2.5 g L -1 and above. Anostraca, Notostraca and Spinicaudata hatchlings were abundant at salinities of 0.5 g L -1 and below, while Copepoda, Daphniidae (Cladocera) and Ostracoda were observed in the highest salinity, but their densities were still lower with increased salinities. Given the importance of large branchiopods in the trophic balance of depression wetlands, their loss may alter the ecological balance and function of these ecosystems.

Klein (CSW16)

CSIR Research Space (South Africa)

De Decker, HP

1989-10-01

Full Text Available This report provides historical overview on river catchment, ecology, biotic and abiotic characteristics and available information on the Klein estuary. Kleinriviersvlei is popularly known as "Hermanus Lagoon". In some of the accounts...

Adrian Stokes and the portrait of Melanie Klein.

Science.gov (United States)

Sayers, Janet

2015-08-01

This paper focuses on the offer by the art writer Adrian Stokes to commission and pay for a portrait of the psychoanalyst Melanie Klein by the artist William Coldstream. It details some of the precursors of this offer in Stokes's preceding involvement first with Klein and then with Coldstream; her response to this offer; and its outcome and aftermath in Stokes's subsequent writing about Klein and Coldstream. Copyright © 2015 Institute of Psychoanalysis.

A new mid-Permian burnetiamorph therapsid from the Main Karoo Basin of South Africa and a phylogenetic review of Burnetiamorpha

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Michael O. Day

2016-12-01

Full Text Available Discoveries of burnetiamorph therapsids in the last decade and a half have increased their known diversity but they remain a minor constituent of middle–late Permian tetrapod faunas. In the Main Karoo Basin of South Africa, from where the clade is traditionally best known, specimens have been reported from all of the Permian biozones except the Eodicynodon and Pristerognathus assemblage zones. Although the addition of new taxa has provided more evidence for burnetiamorph synapomorphies, phylogenetic hypotheses for the clade remain incongruent with their appearances in the stratigraphic column. Here we describe a new burnetiamorph specimen (BP/1/7098 from the Pristerognathus Assemblage Zone and review the phylogeny of the Burnetiamorpha through a comprehensive comparison of known material. Phylogenetic analysis suggests that BP/1/7098 is closely related to the Russian species Niuksenitia sukhonensis. Remarkably, the supposed mid-Permian burnetiids Bullacephalus and Pachydectes are not recovered as burnetiids and in most cases are not burnetiamorphs at all, instead representing an earlier-diverging clade of biarmosuchians that are characterised by their large size, dentigerous transverse process of the pterygoid and exclusion of the jugal from the lateral temporal fenestra. The evolution of pachyostosis therefore appears to have occurred independently in these genera. The resulting biarmosuchian tree is significantly more congruent with the stratigraphic appearance of its constituent taxa than in previous phylogenetic hypotheses and, consequently, does not necessarily constrain the diversification of the Burnetiamorpha to before the Capitanian.

Winnicott's response to Klein.

Science.gov (United States)

Ehrlich, Robert

2004-04-01

The author suggests that, although Donald Winnicott presented some important criticisms of Melanie Klein's work, at times he tried to advance his perspectives too definitively without adequately considering her own. Because of this, he failed to acknowledge sufficiently that he was offering a model of human nature and development that could be revised. The fact that his differences with Klein arose in the context of a complex relationship in which each played numerous roles for the other, especially in the context of their affiliation with the British Psychoanalytical Society, periodically made it difficult for him to present his ideas more carefully and in his more characteristically open manner.

On Kaluza-Klein theory

International Nuclear Information System (INIS)

Salam, A.; Strathdee, J.

1981-10-01

Assuming the compactification of 4+K-dimensional spacetime implied in Kaluza-Klein type theories, we consider the case in which the internal manifold is a quotient space, G/H. We develop normal mode expansions on the internal manifold and show that the conventional gravitational plus Yang-Mills theory (realizing local G symmetry) is obtained in the leading approximation. The higher terms in the expansions give rise to field theories of massive particles. In particular, for the original Kaluza-Klein 4+1-dimensional theory, the higher excitations describe massive, charged, purely spin-2 particles. These belong to infinite dimensional representations of an 0(1,2). (author)

Growth, feed intake and body composition of ostriches (Struthio ...

African Journals Online (AJOL)

the ostrich breeding flock of the Klein Karoo Agricultural. Development Centre and ... The diet was initially formulated according to poultry values. (Du Preez et al., 1984; Du ...... body weight on high or low nutrient density diets. Proc. 9th Symp.

Melanie Klein on mourning: Its relation to pastoral care.

Science.gov (United States)

Hart, C W

1991-09-01

This paper connects the work of Melanie Klein on mourning to the pastor's work with the grief sufferer. Klein holds that mourning is an illness of manic depressive character rooted in infantile development. Klein's description of manic defenses in the face of loss has adult behavioral analogues with which the pastor must deal to bring mourning to resolution.

U-Pb isotopic evidence pertaining to the age and genesis of uranium mineralisation in Karoo sediments

International Nuclear Information System (INIS)

Allsopp, H.L.; Welke, H.J.; Armstrong, R.A.; Clough, W.; Evans, I.B.

1984-01-01

Preliminary investigations have been carried out, using the uranium-lead isotopic method, on the uranium mineralisation that occurs within the Karoo sediments. Two occurences were studied, namely the lower Beaufort sediments (Adelaide Subgroup) in the Beaufort West area and the Molteno Formation sediments in the Ficksburg area. The objective were to determine the age of the mineralisation and to study the mode of formation of the ores. The pattern of U-Pb apparent ages for all the Karoo samples is 207 Pb/ 206 Pb age >> 207 Pb* 235 U age > 206 Pb* 238 U age

The Oskar Klein memorial lectures

CERN Document Server

1994-01-01

The series of Oskar Klein Memorial Lectures is a must-read for those keenly involved or simply interested in exploring the many fascinating aspects of Physics. This volume presents two landmark lectures given by Hans Bethe in October 1990 and Alan H. Guth in June 1991 under the series of Oskar Klein Memorial Lectures. Hans Bethe's lectures dealt with two themes: the astrophysical importance of neutrinos in supernova outbursts and a theoretical account of neutrinos through observations of the neutrino flux from the centre of the sun. Anyone interested in understanding the processes involved in

The use of radiometric-logging techniques to determine uranium grade in certain mineralised Karoo boreholes

International Nuclear Information System (INIS)

Corner, B.; De Beer, G.P.

1976-05-01

During the period September-October 1975, 22 mineralised boreholes in nine different Karoo uranium occurrences were logged radiometrically with the aim of determining to what accuracy the actual uranium grade could be predicted from the gamma logs. The true uranium grades of the mineralised zones logged were known from existing chemical analyses. The results showed that the uranium grades could be predicted to an accuracy of better than 10% through the use of gamma-logging equipment calibrated at Pelindaba, provided that the ore was in equilibrium and that little or no thorium was present. Disequilibrium is, however, prevalent in the Karoo, and in the holes logged it occurred by depletion of uranium relative to its gamma-emitting daughter products. Such effects were mostly confined to the zone above the water table, and it is concluded that for Karoo-type occurrences, the high radiometric background levels observed over extended distances in some boreholes were indicative of radon-gas buildup, and hence of disequilibrium. It is further concluded that radiometric borehole logging can largely replace chemical analyses in the determination of uranium grade for ore-reserve calculations, although chemical checks for disequilibrium would always be necessary [af

The conflict and process theory of Melanie Klein.

Science.gov (United States)

Kavaler-Adler, S

1993-09-01

This article depicts the theory of Melanie Klein in both its conflict and process dimensions. In addition, it outlines Klein's strategic place in psychoanalytic history and in psychoanalytic theory formation. Her major contributions are seen in light of their clinical imperatives, and aspects of her metapsychology that seem negligible are differentiated from these clinical imperatives. Klein's role as a dialectical fulcrum between drive and object relations theories is explicated. Within the conflict theory, drive derivatives of sex and aggression are reformulated as object-related passions of love and hate. The process dimensions of Klein's theory are outlined in terms of dialectical increments of depressive position process as it alternates with regressive paranoid-schizoid-position mental phenomenology. The mourning process as a developmental process is particularly high-lighted in terms of self-integrative progression within the working through of the depressive position.

Anatomy of myxospermic diaspores of selected species in the Succulent Karoo, Namaqualand, South Africa

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H. F. Makouate

2012-12-01

Full Text Available Environmental conditions encountered in arid ecosystems differ vastly from those in more mesic ecosystems. Dispersal strategies in arid environments reflect these differences and many mechanisms have evolved that restrict or hinder dispersal. Myxospermy is a trait developed by plant species from arid regions to restrict diaspore dispersal by means of an anchorage mechanism. Several of the abundant plant species in Namaqualand, within the arid Succulent Karoo Biome, display myxospermy. Diaspores of these species produce copious amounts of mucilage when they are moistened and are anchored to the soil once the mucilage dries out again. This study investigated the origin of the mucilaginous layer of 12 species anatomically, using both light and scanning electron microscopy. The mucilage production of the species investigated could best be grouped into three types: 1, epidermal and sub-epidermal cells of seeds and achenes; 2, specialized tissue in wings or the pappus of achenes; and 3, mucilage excreting hairs. Previous systems for classifying the different types of mucilage production did not recognize the mucilaginous nature of wings or a pappus. A short note on the composition of the mucilage is included.

[An unpublished contribution of Melanie Klein "On Reassurance"].

Science.gov (United States)

Frank, Claudia; Klein, Melanie

2005-01-01

Melanie Klein's unpublished paper on reassurance is presented in German translation. The author shows that it was a contribution to Glover's investigation on psychoanalytic technique in the 1930s. The paper is discussed against the background of the technical discussions conducted in London at that time (e. g. M. Schmideberg, J. Strachey) and of Klein's relevant publications. Although Klein consistently considered "correct" interpretation to be the most effective means of reassurance, she occasionally also accepted a non-interpreting approach. In this respect the paper presented here goes further than any other of her writings.

Klein tunneling phenomenon with pair creation process

Science.gov (United States)

Wu, G. Z.; Zhou, C. T.; Fu, L. B.

2018-01-01

In this paper, we study the Klein tunneling phenomenon with electron-positron pair creation process. Pairs can be created from the vacuum by a supercritical single-well potential (for electrons). In the time region, the time-dependent growth pattern of the created pairs can be characterized by four distinct regimes which can be considered as four different statuses of the single well. We find that if positrons penetrate the single well by Klein tunneling in different statuses, the total number of the tunneling positrons will be different. If Klein tunneling begins at the initial stage of the first status i.e. when the sing well is empty, the tunneling process and the total number of tunneling positrons are similar to the traditional Klein tunneling case without considering the pair creation process. As the tunneling begins later, the total tunneling positron number increases. The number will finally settle to an asymptotic value when the tunneling begins later than the settling-down time t s of the single well which has been defined in this paper.

Late Quaternary landscape evolution in the Great Karoo, South Africa: Processes and drivers.

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Oldknow, Chris; Hooke, Janet; Lang, Andreas

2016-04-01

The Great Karoo spans the north-central part of South Africa at a major climatic boundary. The characteristics, sequences, spatial patterns and drivers of river response to Late Quaternary climate changes in this region remain unclear due to the fragmentary alluvial/colluvial stratigraphic record and the lack of dated palaeoclimatic archives. Dendritic gully networks incised into deep deposits (up to 6 m) of colluvium and alluvium in the upper Sundays River catchment expose a legacy of "cut and fill" features. In 1st order tributaries, these are predominantly discontinuous palaeochannels and flood-outs with localised palaeosols, whereas in 2nd & 3rd order tributaries there are: 1) incised palaeo-geomorphic surfaces, 2) semi-continuous inset terrace sequences, 3) buried palaeo-gully topography. Using a combination of field mapping, logging of sediment outcrops, soil micromorphological and grain size analysis, mineral magnetic measurements and radiometric dating (OSL & 14C), we derive a stratigraphic evolution model which demonstrates a) the number of phases of incision, aggradation and pedogenesis, b) the spatial and temporal extent of each phase and c) the drivers of alluviation and associated feedbacks. Our reconstruction of regional valley alluviation indicates four distinct terrace units of contrasting depositional age. The base of the succession reflects slow aggradation under periglacial conditions associated with the Last Glacial Maximum. Subsequent channel entrenchment, causing terrace abandonment (T1) occurred in the deglacial period when vegetation and rainfall were in anti-phase. Re-instatement of connectivity with deep upland colluvial stores resulted in the injection of a pulse of sediment to valley floors, triggering compartmentalised backfilling (aggradation of T2) which propagated upstream as far as the second order drainage lines. This backfilling restructured the local hydrology, which, in concert with enhanced summer-rainfall, contributed to a

Klein Topological Field Theories from Group Representations

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Sergey A. Loktev

2011-07-01

Full Text Available We show that any complex (respectively real representation of finite group naturally generates a open-closed (respectively Klein topological field theory over complex numbers. We relate the 1-point correlator for the projective plane in this theory with the Frobenius-Schur indicator on the representation. We relate any complex simple Klein TFT to a real division ring.

Kaluza-Klein theories. 21

International Nuclear Information System (INIS)

Maheshwari, A.

1989-01-01

The old Kaluza-Klein theory in five dimensions for unification of electromagnetism and gravitation is discussed and put in a modern perspective so that one can now generalize the approach to unify arbitrary (non-Abelian) gauge fields with gravitation. The internal and spacetime symmetries are unified by making the internal symmetries as spacetime symmetries of 'unobservable' dimensions. This necessitates the introduction of higher dimensions - eleven in particular to accommodate the standard theory. But one has to face up the fate of the extra dimensions. Spontaneous compactification is one solution and this is treated in detail, as also is the harmonic expansions necessary to obtain the particle spectrum of Kaluza-Klein theories. The chapter ends with a discussion of the problem of chiral fermions in these theories. (author). 16 refs

Fermion interactions with a Kaluza-Klein dyon

International Nuclear Information System (INIS)

Xi, Z.M.

1986-04-01

The fermion dynamics in the background of a five-dimensional Kaluza-Klein dyon is studied. It is found that the hamiltonian is self-adjoint despite the singular nature of the origin, and the fermion scattering on the dyon in the lowest angular momentum j = 0 channel is a helicity flip process. The possibility for charge-exchange process in the non-Abelian Kaluza-Klein theories is discussed

The nonsymmetric-nonabelian Kaluza-Klein theory

International Nuclear Information System (INIS)

Kalinowski, M.W.

1983-01-01

This paper is devoted to an (n+4)-dimensional unification of Moffat's theory of gravitation and Yang-Mills field theory with nonabelian gauge group G. We found 'interference effects' between gravitational and Yang-Mills (gauge) fields which appear to be due to the skewsymmetric part of the metric of Moffat's theory and the skewsymmetric part of the metric on the group G. Our unification, called the nonsymmetric-nonabelian Kaluza-Klein theory, becomes classical Kaluza-Klein theory if the skewsymmetric parts of both metrics are zero. (author)

The ego according to Klein: return to Freud and beyond.

Science.gov (United States)

Blass, Rachel B

2012-02-01

This paper explores fundamental dimensions of Melanie Klein's concept of the ego through a detailed study of the writings of Klein and her early colleagues (Paula Heimann, Susan Isaacs and Joan Riviere). The study examines three central issues: (a) the basic theoretical framework for Klein's conceptualization of the ego, and specifically how her conceptualization builds on Freud's structural and dual instinct models; (b) the processes involved in the development of the ego and its capacities (including the development from id to ego and from ego to superego); and (c) the view of the ego as an object of phantasy. Through this examination, the study demonstrates that Klein's conceptualization of the ego is firmly grounded both in Freud's formulations about the ego and in his theoretical and metapsychological approach to thinking about the ego. This counters the prevalent view that Klein was only focused on clinical understandings, unconcerned with theory and fuzzy in her abstract thinking. More specifically, it counters the view that Klein did not really have a concept of the ego in any well-structured sense of the term (Britton, 2003; Hinshelwood, 1994; Segal, 2001). The study considers the sources of these misconceived views. Finally, it argues that discarding such views allows us to appreciate better the richness of Klein's thinking, her theoretical affinities to Freud, and the role of theory in the development and justification of psychoanalysis. Copyright © 2011 Institute of Psychoanalysis.

Determinants of Smoking Cessation among Adolescents in South Africa

Science.gov (United States)

Panday, Saadhna; Reddy, S. Priscilla; Ruiter, Robert A. C.; Bergstrom, Erik; de Vries, Hein

2005-01-01

Data is required on the motivational determinants of smoking cessation among a multi-ethnic sample of adolescents in South Africa. The I-Change Model was used to explore the determinants of smoking cessation among a sample of 1267 Black African, Colored and White Grade 9-11 monthly smokers and former smokers in the Southern Cape-Karoo region.…

Tectonic and climatic controls on continental depositional facies in the Karoo Basin of northern Natal, South Africa

Science.gov (United States)

Turner, Brian R.

1986-02-01

The eastern Karoo Basin, South Africa, contains a thick sequence of terrigenous clastic sediments comprising a meanderbelt facies, braided channel facies divided into coarse and fine subfacies, fluviolacustrine facies and aeolian facies. Depositional trends and changes in fluvial style reflect a progressive increase in aridity of the climate under stable tectonic conditions, interrupted by two phases of source area tectonism and the development of fine and coarse clastic wedges of the braided channel subfacies; the latter signifying a short interlude of cool, wet conditions. The fine braided channel subfacies occurs in the upper part of the meanderbelt facies, which was deposited by ephemeral, meandering mixed-load streams of variable discharge and sinuosity, under dry, semi-arid climatic conditions. These deposited complex, internally discordant channel sands and well-developed levee deposits. Following deposition of the coarse braided channel subfacies semi-arid conditions returned and fluvial deposition was dominated by ephemeral, straight to slightly sinuous mixed load streams characterised by simple channel sand bodies. As the aridity of the climate increased, the streams became more localised and carried an increasing proportion of fines. Interbedded with and overlying the fluvial deposits is a mudstone-dominated lacustrine sequence grading up into aeolian sands suggesting a playa lake-type situation. The general absence of evaporites from these sediments is attributed to the fresh nature of the lake waters, as evidenced by the freshwater aquatic organisms and clay-mineral suite, the lack of adequate inflow for solute accumulation and the removal of dust impregnated by salts from the surface of the dry lake bed during the dry season by superheated, upward-spiralling columns of air. Broadly similar environments to the fluvio-lacustrine and aeolian facies sequence are to be found in the Lake Eyre Basin of central Australia and the Okavango "delta" of northern

The evil of sluits: a re-assessment of soil erosion in the Karoo of South Africa as portrayed in century-old sources.

Science.gov (United States)

Rowntree, K M

2013-11-30

Deep, linear gullies are a common feature of the present landscape of the Karoo of South Africa, where they were known locally in the early twentieth century as 'sluits'. Recent research has shown that many of these features are now stable and are no longer significant sediment sources, although they are efficient connectors in the landscape. Because most of the gully networks predate the first aerial photographs, little is known in the scientific literature about the timing of their formation. One secondary source, however, throws interesting light on the origin of these features, and the early response by landowners to their rehabilitation. The Agricultural Journal of the Cape of Good Hope at the turn of the Twentieth Century carried a number of articles by farmers and agricultural officers concerning the "evil of sluits". The authors gave accounts of widespread incision of valley bottoms by deep, wide gullies. Many of these gullies had been in existence for some thirty years but apparently had formed within living memory. A number of attempts to prevent further erosion had been put in place at the time of writing. This paper presents a review of land degradation, specifically gully erosion, and rehabilitation recommendations as given by authors writing in this journal. It reflects on the findings in the context of assessing land degradation processes through the local knowledge portrayed in the journal. Copyright © 2013 Elsevier Ltd. All rights reserved.

Melanie Klein's letters addressed to Marcelle Spira (1955-1960).

Science.gov (United States)

Quinodoz, Jean-Michel

2009-12-01

Between 1955 and 1960, Melanie Klein wrote some 45 hitherto unpublished letters to Marcelle Spira, the Swiss psychoanalyst living at that time in Geneva. In 2006, after Spira's death, these letters were deposited with the Raymond de Saussure Psychoanalysis Centre in Geneva. They are the only known letters that Klein addressed to her psychoanalyst colleagues. Several topics are mentioned in them: (1) the meetings between the two women in Geneva and London; (2) Spira's contribution to Boulanger's translation into French of The Psychoanalysis of Children, which Klein herself carefully revised; (3) the papers that Klein was at that time working on, including Envy and Gratitude; (4) Spira's own work; (5) the difficulties that Spira, a Kleinian psychoanalyst who trained in Buenos Aires, was encountering in her attempt to be admitted to the Swiss Psychoanalytical Society; and (6) a few items of personal and family news. In addition to the invaluable historical information that these letters provide, they offer us a very moving epistolary self-portrait of Melanie Klein, enabling us to discover her personality in the final years of her life - she died in September 1960, just two months after writing her last letter to Spira.

Phases of Kaluza-Klein black holes

DEFF Research Database (Denmark)

Elvang, Henriette; Obers, Niels; Harmark, Troels

2004-01-01

We review the latest progress in understanding the phase structure of static and neutral Kaluza-Klein black holes, i.e. static and neutral solutions of pure gravity with an event horizon and with asymptotics Md × S1, Md being d-dimensional Minkowski space.......We review the latest progress in understanding the phase structure of static and neutral Kaluza-Klein black holes, i.e. static and neutral solutions of pure gravity with an event horizon and with asymptotics Md × S1, Md being d-dimensional Minkowski space....

Kaluza-Klein inflation

International Nuclear Information System (INIS)

Ishihara, Hideki.

1984-05-01

Dynamical evolution of the Kaluza-Klein space-time is studied using higher dimensional Einstein equation with dust matter. The difference of the topology between the usual space and the internal space gives rise to the segregation of these subspaces. Furthermore the contraction of the internal space causes the inflation of the usual space. (author)

Boosted black holes on Kaluza-Klein bubbles

International Nuclear Information System (INIS)

Iguchi, Hideo; Mishima, Takashi; Tomizawa, Shinya

2007-01-01

We construct an exact stationary solution of black-hole-bubble sequence in the five-dimensional Kaluza-Klein theory by using solitonic solution-generating techniques. The solution describes two stationary black holes with topology S 3 on a Kaluza-Klein bubble and has a linear momentum component in the compactified direction. We call the solution boosted black holes on Kaluza-Klein bubble because it has the linear momentum. The Arnowitt-Deser-Misner mass and the linear momentum depend on the two boosted velocity parameters of black holes. In the effective four-dimensional theory, the solution has an electric charge which is proportional to the linear momentum. The solution includes the static solution found by Elvang and Horowitz. The small and the big black holes limits are investigated. The relation between the solution and the single boosted black string are considered

Potential Health Risks Posed by Plant-Derived Cumulative Neurotoxic Bufadienolides in South Africa

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Christo Botha

2016-03-01

Full Text Available Bufadienolide-type cardiac glycosides have a worldwide distribution and are mainly synthesized by plants, but there are also animal sources. In South Africa, members of three genera of the Crassulaceae (Cotyledon, Tylecodon and Kalanchoe cause a unique chronic form of cardiac glycoside poisoning, predominantly in small stock. This paretic/paralytic condition is referred to as “krimpsiekte”, cotyledonosis or “nenta”. “Krimpsiekte” is a plant poisoning only reported from South Africa and is regarded as the most important plant poisoning of small stock in the semi-arid Little Karoo and southern fringes of the Great Karoo. The toxicosis is caused by cumulative bufadienolides which have neurotoxic properties. Four types of cumulative neurotoxic bufadienolides, namely cotyledoside, and the tyledosides, orbicusides and lanceotoxins, have been isolated. Based on the structure activity relationships and certain toxicokinetic parameters possible reasons for their accumulation are presented. Consumption of edible tissues from animals that have ingested these plants poses a potential risk to humans.

Obituary: Michael John Klein, 1940-2005

Science.gov (United States)

Gulkis, Samuel

2006-12-01

Michael John Klein died on 14 May 2005 at home in South Pasadena, California. The cause of death was tongue cancer that metastasized to the lungs. He was a non-smoker. Mike was a passionate radio astronomer, a trusted astronomical observer, an educator and a family man. Mike was born on 19 January 1940 in Ames, Iowa, the son of Florence Marie (Graf) and Fred Michael Klein. His mother was a homemaker, and his father was a banker. Mike had two older sisters, Lois Jean (Klein) Flauher and Marilyn June (Klein) Griffin. In 1962, Mike married his high school sweetheart Barbara Dahlberg, who survives him along with their three children, Kristin Marie (Klein) Shields, Michael John Klein Jr., Timothy Joel Klein, and six grandchildren. Mike developed a love for astronomy early in his life, and credited an early morning, newspaper-delivery route that he had at age twelve, which took him outside well before sunrise. He told family members that as he walked along his route, he stared into the sky and wondered what everything was. He studied sky charts, located stars, and began to understand how the planets shifted their positions relative to the stars each day. Another big influence in Mike's life was his brother in-law, Jim Griffin. Jim helped Mike understand that his passion for science did not have to remain a hobby, but could and should become a career. Jim's encouragement led Mike to attend Iowa State University in Ames, where he earned a BS in electrical engineering in 1962. Mike then started graduate school in electrical engineering at Michigan State, but after one semester transferred to the University of Michigan, Ann Arbor, where he earned an MS (1966) and PhD (1968) in astronomy. His doctoral dissertation, under the direction of Professor Fred Haddock, was based on extensive observations of the planets and examined the physical and thermal properties of planetary atmospheres and surfaces. Mike was awarded a Resident Research Associate position at JPL by the National

THE PSYCHOANALYTIC CONTRIBUTIONS OF MELITTA SCHMIDEBERG KLEIN. MORE THAN MELANIE KLEIN'S REBEL DAUGHTER.

Science.gov (United States)

Cassullo, Gabriele

2016-03-01

Compared to the impact of the work of Melanie Klein on the history of psychoanalysis, the contributions of her daughter, Melitta Schmideberg, passed almost unnoticed. At present, Schmideberg is solely remembered for having harshly attacked her mother at the start of the Controversial Discussions of the British Psycho-Analytical Society and for having coined the fitting expression "stable instability" in order to describe borderline and asocial personality disorders. However, the author discusses how the early groundbreaking discoveries of Klein with regards to primitive anxieties were the result of the joint work and thinking of Melanie and Melitta. Moreover, he argues that the conflict between the two, along with the subsequent polarization of their views, did not facilitate the development of psychoanalysis, neither did it help the analytic community to recognize the value of Melitta's contributions to psychoanalysis.

Bosonic analog of the Klein paradox

International Nuclear Information System (INIS)

Wagner, R. E.; Ware, M. R.; Su, Q.; Grobe, R.

2010-01-01

The standard Klein paradox describes how an incoming electron scatters off a supercritical electrostatic barrier that is so strong that it can generate electron-positron pairs. This fermionic system has been widely discussed in textbooks to illustrate some of the discrepancies between quantum mechanical and quantum field theoretical descriptions for the pair creation process. We compare the fermionic dynamics with that of the corresponding bosonic system. We point out that the direct counterpart of the Pauli exclusion principle (the central mechanism to resolve the fermionic Klein paradox) is stimulated emission, which leads to the resolution of the analogous bosonic paradox.

Soliton solutions of coupled nonlinear Klein-Gordon equations

International Nuclear Information System (INIS)

Alagesan, T.; Chung, Y.; Nakkeeran, K.

2004-01-01

The coupled nonlinear Klein-Gordon equations are analyzed for their integrability properties in a systematic manner through Painleve test. From the Painleve test, by truncating the Laurent series at the constant level term, the Hirota bilinear form is identified, from which one-soliton solutions are derived. Then, the results are generalized to the two, three and N-coupled Klein-Gordon equations

On the generalization of the Kaluza-Klein theory

International Nuclear Information System (INIS)

Rosu, Ion

2003-01-01

The goal of this paper is to present the Kaluza-Klein theory. In the first part we will discuss the theory elaborated by Kaluza and Klein, in a Riemann space with five dimensions, which unifies the gravitation with electromagnetism. The second part debates the generalization of this theory in a space with 4+n dimensions. This is a mathematical product between the Riemann 4-dimension variety and the G/H n-dimensional homogenous space. In the last part we will propose a theory Kaluza-Klein like in the fiber bundle space with 4+n dimensions. Every part is structured as follows: the metric tensor G will be identified for the gravitation and the potentials Yang-Mills; then the equations of geodesics and the equations of the field will be deduced. (author)

Primitive object love in Melanie Klein's thinking; early theoretical influences.

Science.gov (United States)

Likierman, M

1993-04-01

Melanie Klein's thinking on early object love is pivotal to her vision of development. Yet within her texts it is often enmeshed in complex formulations that obscure its full significance. A greater clarity in viewing Klein's concept of early object love is achieved through tracing some of its historical origins. The author notes that it was inspired by aspects of Ferenczi's theory, hence its similarities with the concept of 'primary love' formulated by another of Ferenczi's analysands, Michael Balint. Ferenczi's thinking on the subject formed part of a broader network of theoretical developments in the history of psychoanalytic ideas. These are shown to have origins in Freud's fluctuations between a 'passive' and a 'genital' characterisation of infantile sexuality. A dialectical tension between these two possibilities, as maintained in the Freudian texts, was partly embodied in the differing outlooks of Klein's two psychoanalysts, Abraham and Ferenczi. The author suggests that it is a mixture of their approaches that partly shaped Klein's thinking on the earliest experiences of love. After outlining these developments the author analyses the nature of early object love as it emerges from Klein's powerful, if intermittent descriptions in the texts. The analysis also tackles a textual ambiguity in Klein's formulations, showing that she explored two kinds of primitive ideal experience without explicitly differentiating them. Such differentiation is important inasmuch as it highlights negative and positive aspects of Kleinian theory at root.

Dynamical symmetries of the Klein-Gordon equation

International Nuclear Information System (INIS)

Zhang Fulin; Chen Jingling

2009-01-01

The dynamical symmetries of the two-dimensional Klein-Gordon equations with equal scalar and vector potentials (ESVPs) are studied. The dynamical symmetries are considered in the plane and the sphere, respectively. The generators of the SO(3) group corresponding to the Coulomb potential and the SU(2) group corresponding to the harmonic oscillator potential are derived. Moreover, the generators in the sphere construct the Higgs algebra. With the help of the Casimir operators, the energy levels of the Klein-Gordon systems are yielded naturally

Melanie Klein's metapsychology: phenomenological and mechanistic perspective.

Science.gov (United States)

Mackay, N

1981-01-01

Freud's metapsychology is the subject of an important debate. This is over whether psychoanalysis is best construed as a science of the natural science type or as a special human science. The same debate applies to Melanie Klein's work. In Klein's metapsychology are two different and incompatible models of explanation. One is taken over from Freud's structural theory and appears to be similarly mechanistic. The other is clinically based and phenomenological. These two are discussed with special reference to the concepts of "phantasy" and "internal object".

Late Permian rivers draining the uplifted Cape Fold Belt: magnetostratigraphy and detrital thermochronology of Karoo Basin sediments

Science.gov (United States)

Tohver, E.; Schmieder, M.; Arosio, R.; Lanci, L.; Jourdan, F.; Wilson, A.; Ratcliffe, K.; Payenberg, T.; Flint, S.

2017-12-01

The Cape Fold Belt and Karoo Basin of southern Africa formed during the Permian orogeny that affected the 13,000 km southern margin of the Gondwanan continent. In this report, we synthesize new and recent magnetostratigraphic and geochronologic data to establish a chronostratigraphic framework for Karoo Basin sedimentation for comparison with the thermal/exhumation history of the Cape Fold Belt. The source-sink model is evaluated using new data from detrital muscovite and zircon from 2 km composite section of fluvial sandstone and mudstones deposited at ca.275 - 260 Ma. Coherent age populations of detrital zircon grains indicate rapid incorporation of contemporary volcanic ashbeds into the sedimentary record. In contrast, cooling age distributions of detrital muscovite are typically ca. 5 - 10 Ma older than the age of deposition; similar lag times are observed from modern sediments in active mountain belts. Trace element geochemical signatures demonstrate a clear shift towards crustal recycling via headland erosion in the Beaufort Group relative to the underlying Ecca Group. These observations pinpoint the age of uplift for the Cape Fold Belt, which began to function as the major sediment source for the foreland Karoo Basin with the deposition of the uppermost Ecca Group and basal Beaufort Group.

Karoo airborne geophysical survey

International Nuclear Information System (INIS)

Cole, D.J.; Stettler, E.H.

1984-01-01

Thirty four uranium anomalies were selected for ground follow-up from the analogue spectrometer records of Block 4 of the Karoo Airborne Geophysical Survey. The anomalies were plotted on 1:50 000 scale topographic maps and to 1:250 000 scale maps which are included in this report. The anomaly co-ordinates are tabulated together with the farms on which they occur. Results of the ground follow-up of the aerial anomalies are described. Twenty two anomalies are related to uranium mineralisation of which seventeen occur over baked mudstone adjacent to a dolerite intrusion. Five are located over fluvial channel sandstone of the Beaufort Group and subsurface mineralised sandstone may be present. The other twelve anomalies are spurious. Of the anomalies located over baked mudstone, fifteen emanate from ferruginous mudstone of the Whitehill Formation west of longitude 21 degrees 15 minutes. One of the two remaining anomalies over baked mudstone occurs over the Prince Albert Formation and the other anomaly is over baked mudstone and calcareous nodules of the Beaufort Group. The general low uranium values (less than 355 ppm eU3O8) render the occurrences uneconomic

Massive Kaluza-Klein theories and their spontaneously broken symmetries

International Nuclear Information System (INIS)

Hohm, O.

2006-07-01

In this thesis we investigate the effective actions for massive Kaluza-Klein states, focusing on the massive modes of spin-3/2 and spin-2 fields. To this end we determine the spontaneously broken gauge symmetries associated to these 'higher-spin' states and construct the unbroken phase of the Kaluza-Klein theory. We show that for the particular background AdS 3 x S 3 x S 3 a consistent coupling of the first massive spin-3/2 multiplet requires an enhancement of local supersymmetry, which in turn will be partially broken in the Kaluza-Klein vacuum. The corresponding action is constructed as a gauged maximal supergravity in D=3. Subsequently, the symmetries underlying an infinite tower of massive spin-2 states are analyzed in case of a Kaluza-Klein compactification of four-dimensional gravity to D=3. It is shown that the resulting gravity-spin-2 theory is given by a Chern-Simons action of an affine algebra and also allows a geometrical interpretation in terms of 'algebra-valued' differential geometry. The global symmetry group is determined, which contains an affine extension of the Ehlers group. We show that the broken phase can in turn be constructed via gauging a certain subgroup of the global symmetry group. Finally, deformations of the Kaluza-Klein theory on AdS 3 x S 3 x S 3 and the corresponding symmetry breakings are analyzed as possible applications for the AdS/CFT correspondence. (Orig.)

Melanie Klein and countertransference: a note on some archival material.

Science.gov (United States)

Hinshelwood, R D

2008-01-01

Five pages of notes were found in the Melanie Klein Archives at the Wellcome Library that concern her views on countertransference in 1953. Because of the paucity of references to countertransference in Klein's published writings these Notes fill in out knowledge. Her views were provoked by the work her students were doing in their experimental analyses of schizophrenic patients. Apocryphal stories suggest that Klein remained aligned with Freud's view of countertransference as simply interference. The Notes confirm that, whilst there is some truth to that, she did have a more sophisticated and nuanced view of the unconscious relations between analyst and analysand.

AdS. Klein-Gordon equation

OpenAIRE

Bel, Ll.

2014-01-01

I propose a generalization of the Klein-Gordon equation in the framework of AdS space-time and exhibit a four parameter family of solutions among which there is a two parameter family of time-dependent bound states.

Reprint of: The evil of sluits: a re-assessment of soil erosion in the Karoo of South Africa as portrayed in century-old sources.

Science.gov (United States)

Rowntree, K M

2014-06-01

Deep, linear gullies are a common feature of the present landscape of the Karoo of South Africa, where they were known locally in the early twentieth century as 'sluits'. Recent research has shown that many of these features are now stable and are no longer significant sediment sources, although they are efficient connectors in the landscape. Because most of the gully networks predate the first aerial photographs, little is known in the scientific literature about the timing of their formation. One secondary source, however, throws interesting light on the origin of these features, and the early response by landowners to their rehabilitation. The Agricultural Journal of the Cape of Good Hope at the turn of the Twentieth Century carried a number of articles by farmers and agricultural officers concerning the "evil of sluits". The authors gave accounts of widespread incision of valley bottoms by deep, wide gullies. Many of these gullies had been in existence for some thirty years but apparently had formed within living memory. A number of attempts to prevent further erosion had been put in place at the time of writing. This paper presents a review of land degradation, specifically gully erosion, and rehabilitation recommendations as given by authors writing in this journal. It reflects on the findings in the context of assessing land degradation processes through the local knowledge portrayed in the journal. Copyright © 2014. Published by Elsevier Ltd.

New airborne geophysical data from the Waterberg coalfield. South Africa's major future energy source

CSIR Research Space (South Africa)

Fourie, CJS

2008-11-01

Full Text Available Formation (110m thick in the south) • Recent cover is from the weathering of gneiss of the Limpopo Mobile Belt and the Karoo rock in the north; but from Waterberg sandstones in the south • Intrusive rocks – the most important of these rocks are those... 2) shows the northern contact of the Ellisras Basin clearly. It also shows the large block faulting and radioactive material eroding from the source (Waterberg Sandstones) in the south into the sediment load of the north-flowing Mokolo River...

Geometrical aspects of Kaluza-Klein theory

International Nuclear Information System (INIS)

Maia, M.D.

1983-08-01

The standard approaches to Kaluza-Klein theory assume the existence of a high dimensional space, from which the four-dimensional space-time would be recovered by a dimensional reduction procedure. In the present note the four-dimensional space-time is regarded as a hypersurface locally embedded in the ever-present (4+n)-dimensional space. In the simplest case where the high dimensional space is taken to be flat, the Kaluza-Klein metric is derived from the embedding assumption. However, this metric is invertible only if the range of the extra n coordinates is limited to an n - dimensional sphere with radius proportional to the local curvature radius of the space-time. Almost independently of this compactification the dimensional reduction, here described in terms of ''complete confinement'', is achieved by a symmetry breaking leading to P 4 x G and which is triggered by the limit of vanishing gravitation. The dynamics for an observer confined to the four-dimensional space-time is described by the embedding integrability conditions. On the other hand for a non-confined observer a unifying picture close to the Kaluza-Klein objectives is obtained. Finally a brief analysis of fermions and fermion masses is also included. (author)

Non-linear electrodynamics in Kaluza-Klein theory

International Nuclear Information System (INIS)

Kerner, R.

1987-01-01

The most general variational principle based on the invariants of the Riemann tensor and leading to the second order differential equations should contain, in dimensions higher than four, the invariants of the Gauss-Bonnet type. In five dimensions the lagrangian should be a linear combination of the scalar curvature and the second-order invariant. The equations of the electromagnetic field are derived in the absence of scalar and gravitational fields of the Kaluza-Klein model. They yield the unique extension of Maxwell's system in the Kaluza-Klein theory. Some properties of eventual solutions are discussed [fr

Massive Kaluza-Klein theories and their spontaneously broken symmetries

Energy Technology Data Exchange (ETDEWEB)

Hohm, O.

2006-07-15

In this thesis we investigate the effective actions for massive Kaluza-Klein states, focusing on the massive modes of spin-3/2 and spin-2 fields. To this end we determine the spontaneously broken gauge symmetries associated to these 'higher-spin' states and construct the unbroken phase of the Kaluza-Klein theory. We show that for the particular background AdS{sub 3} x S{sup 3} x S{sup 3} a consistent coupling of the first massive spin-3/2 multiplet requires an enhancement of local supersymmetry, which in turn will be partially broken in the Kaluza-Klein vacuum. The corresponding action is constructed as a gauged maximal supergravity in D=3. Subsequently, the symmetries underlying an infinite tower of massive spin-2 states are analyzed in case of a Kaluza-Klein compactification of four-dimensional gravity to D=3. It is shown that the resulting gravity-spin-2 theory is given by a Chern-Simons action of an affine algebra and also allows a geometrical interpretation in terms of 'algebra-valued' differential geometry. The global symmetry group is determined, which contains an affine extension of the Ehlers group. We show that the broken phase can in turn be constructed via gauging a certain subgroup of the global symmetry group. Finally, deformations of the Kaluza-Klein theory on AdS{sub 3} x S{sup 3} x S{sup 3} and the corresponding symmetry breakings are analyzed as possible applications for the AdS/CFT correspondence. (Orig.)

Dissociating Word Frequency and Age of Acquisition: The Klein Effect Revived (and Reversed)

Science.gov (United States)

Dewhurst, Stephen A.; Barry, Christopher

2006-01-01

The Klein effect (G. S. Klein, 1964) refers to the finding that high-frequency words produce greater interference in a color-naming task than low-frequency words. The present study used the Klein effect to investigate the relationship between frequency and age of acquisition (AoA) by measuring their influence on color naming. Two experiments…

["Is it an animal inside? "Melanie Klein's unpublished Don Juan Paper (1939)].

Science.gov (United States)

Frank, Claudia

2008-01-01

Klein had been asked to contribute an article to the birthday number of the International Journal for Jones. The author outlines how she hurriedly wrote a text about Don Juan which, however, was rejected by the editor. Essential parts of it are presented in German translation. The manuscript is discussed in the context of Klein's published work as well as of the relevant contemporary literature. In Klein's view, Don Juan's genitality is determined by oral impulses and fears. By his manic acting out he attempts to ward off a depressive break-down. The paper ends with some reflections about why Klein--ontrary to her intention--failed to revise her manuscript for later publication.

A neurose obsessiva sob a ótica de Melanie Klein

Directory of Open Access Journals (Sweden)

Marcos Leandro Klipan

2012-12-01

Full Text Available Essa pesquisa aborda o tema 'neurose obsessiva' na obra de Melanie Klein. Assim, foi possível estudar um panorama histórico da construção do pensamento dessa autora - tendo em vista que seguimos um itinerário cronológico de seus textos - e, como consequência importante, obter uma dimensão epistemológica dessa construção. Isso porque a neurose obsessiva constitui-se como um destacado elemento organizador da obra de Klein, sobretudo nas décadas de 1920 e 1930, período que marcou o atendimento dos primeiros pacientes da autora que, em sua maioria, eram crianças que sofriam de neurose obsessiva.The obsessive neurosis from Melanie Klein's optic. This research focuses on obsessive neurosis in Melanie Klein's. Thus, it was also possible to study a historical broad view of the construction of this author's thought, having in mind that a chronological itinerary was followed, and, as an important consequence, an epistemological dimension of this construction was obtained. This was so because the obsessive neurosis constitutes an outstanding organizing element in Klein's work, mainly in the 1920's and 30's. This time was marked by the observation of the author's first patients, who were, in their majority, children suffering from obsessive neurosis.

Klein, Ferenczi and the clinical diary.

Science.gov (United States)

Hernandez-Halton, Isabel

2015-03-01

The aim of this article is to revisit Ferenczi's Clinical Diary (1932) to investigate the influence he had on Melanie Klein's work. It starts from the position that insufficient recognition has been given to Ferenczi's contribution to Klein's body of work and her professional development. Her analysis with Ferenczi lasted 5 years, a relatively long analysis for the period. It explores his influence in three specific areas: the importance of raw and early emotion in the maternal bond, the importance of freedom and authenticity in the analytic relationship, and finally the use of transference and countertransference feelings. Ferenczi's ill-fated experiment with mutual analysis will be discussed as it opened up a route to explore the analytic relationship, with important consequences for the future development of psychoanalysis.

Oskar Klein

Science.gov (United States)

Fischer-Hjalmars, Inga; Laurent, Bertel

2014-03-01

Oskar Klein died on the fifth of February 1977 at the age of eighty-two. One of the most prominent Swedish physicists ever and an outstanding personality in the field of culture had passed away. He was a man whose interests knew no limits and as a scientist he greatly enriched our understanding of Nature. All those who knew him were astounded by his profound thinking, wealth of ideas, extensive insight and humanism, qualities that obviously had been stimulated by the spirit in his parents' home. His father, rabbi and professor in Stockholm, was deeply engaged in theological and humanitarian issues...

Antiparticle in Light of Einstein-Podolsky-Rosen Paradox and Klein Paradox

OpenAIRE

Ni, Guang-jiong; Guan, Hong; Zhou, Weimin; Yan, Jun

2000-01-01

The original version of Einstein-Podolsky-Rosen (EPR) paradox and the Klein paradox of Klein-Gordon (KG) equation are discussed to show the necessity of existence of antiparticle with its wavefunction being fixed unambiguously. No concept of "hole" is needed.

Julia Kristeva: Das weibliche Genie – Melanie Klein. Gießen: Psychosozial-Verlag 2008

Directory of Open Access Journals (Sweden)

Lilli Gast

2009-07-01

Full Text Available Julia Kristeva widmet sich im zweiten Teil ihrer Trilogie über das weibliche Genie dem Leben und Werk von Melanie Klein, die mit ihren Arbeiten über die früheste Verfasstheit des Psychischen das psychoanalytische Denken für die Psychosen und den Wahn aufschloss und die Rolle des Mütterlichen im psychoanalytischen Diskurs neu definierte. In ihrer Auseinandersetzung mit Klein gelingt Kristeva nicht nur eine ausgesprochen gelungene Einführung in Kleins Denken, sondern auch eine Analyse weiblicher Intellektualität im 20. Jahrhundert. Zudem werden die Schnittstellen im Denken Kleins und Kristevas sichtbar.Julia Kristeva devotes this second installment of her trilogy on feminine genius to the life and work of Melanie Klein. Klein’s work on the early state of the psyche opened psychoanalytical thinking to psychoses, delusion, and the redefined the role of the motherly in psychoanalytical discourse. In her discussion of Klein, Kristeva provides not only a markedly insightful introduction to Klein’s thinking, but also an analysis of female intellectuality in the 20th century. Moreover, the reader clearly sees the interconnections between Klein and Kristeva’s thinking.

A Kaluza–Klein inspired action for chiral p-forms and their anomalies

International Nuclear Information System (INIS)

Bonetti, Federico; Grimm, Thomas W.; Hohenegger, Stefan

2013-01-01

The dynamics of chiral p-forms can be captured by a lower-dimensional parity-violating action motivated by a Kaluza–Klein reduction on a circle. The massless modes are (p−1)-forms with standard kinetic terms and Chern–Simons couplings to the Kaluza–Klein vector of the background metric. The massive modes are p-forms charged under the Kaluza–Klein vector and admit parity-odd first-order kinetic terms. Gauge invariance is implemented by a Stückelberg-like mechanism using (p−1)-forms. A Chern–Simons term for the Kaluza–Klein vector is generated at one loop by massive p-form modes. These findings are shown to be consistent with anomalies and supersymmetry for six-dimensional supergravity theories with chiral tensor multiplets

Financial costs of ecologically nonsustainable farming practices in a semiarid system

CSIR Research Space (South Africa)

Herling, MC

2009-11-01

Full Text Available Nonsustainable ostrich farming practices have degraded large areas of the Little Karoo, a semiarid region in South Africa. The Little Karoo lies within the Succulent Karoo biome, a recognized biodiversity hotspot. A financial feasibility analysis...

Affetto e pensiero nel modello Klein-Bion

Directory of Open Access Journals (Sweden)

Marco Innamorati

2010-01-01

Full Text Available Affect and Thought in the Klein-Bion Model - This paper investigates the development of the psychoanalytic theory of affect according to the Klein/Bion approach, with special regard to the relationship between affect and thought which has strategic importance in the complex picture in post-war Anglo-Saxon psychoanalysis. Klein’s contributions on affect are discussed and confronted with the other elements of the psychological world: representations, drives, objects and positions. The second part of the paper presents and discusses Bion’s theory of “emotional experiences”, in which a primordial identity between thought and feelings generates every form of knowledge.

Continuum solutions of the Klein-Gordon equation

International Nuclear Information System (INIS)

Jansen, G.; Pusch, M.; Soff, G.

1987-10-01

We construct explicit solutions of the Klein-Gordon equation for continuum states. The role of the energy in the single-particle Klein-Gordon theory is elucidated. Special emphasis is laid on the determination of resonance states in the continuum for overcritical potentials. As examples for long-range interaction we depict solutions for the Coulomb potential of a point-like nucleus as an extended nucleus. The square-well potential and the exponential potential are treated to exemplify pecularities of short-range interactions. We also derive continuum solutions for a scalar interaction of square-well type. Finally we discuss the behaviour of a spin-0 particle in an external homogeneous magnetic field. (orig.)

The Poisson equation on Klein surfaces

Directory of Open Access Journals (Sweden)

Monica Rosiu

2016-04-01

Full Text Available We obtain a formula for the solution of the Poisson equation with Dirichlet boundary condition on a region of a Klein surface. This formula reveals the symmetric character of the solution.

A new look at the theory of Melanie Klein.

Science.gov (United States)

Stein, R

1990-01-01

This paper tried to show that Melanie Klein's theory can very profitably be viewed as a descriptive theory of strong emotions rather than an instinct or developmental theory. Furthermore, since in Klein's thinking feelings 'create' objects, the primacy of feelings in this theory is central. The paper contains a short chronological study of Klein's formulations of psychic phenomena in terms of affects. It is also maintained that the paranoid-schizoid and the depressive positions are constellations of affects and of reactions to them; that psychic development is essentially in terms of the capacity to tolerate feelings, and that the basic conflict in mental life is between feelings of love and hate and associated feelings. Such a view solves many of the conceptual difficulties of Kleinian theory and in addition promises rewarding insights into the world of feelings.

Klein paradox in the Breit equation

International Nuclear Information System (INIS)

Krolikowski, W.; Turski, A.; Rzewuski, J.

1979-01-01

We demonstrate that in the Breit equation with a central potential V(r) having the property V(r 0 )=E there appears a Klein paradox at r=r 0 . This phenomenon, besides the previously found Klein paradox at r→infinite appearing if V(r)→infinite at r→infinite, seems to indicate that in the Breit equation valid in the single-particle theory the sea of particle-antiparticle pairs is not well separated from the considered two-body configuration. We conjecture that both phenomena should be absent from the Salpeter equation which is consistent with the hole theory. We prove this conjecture in the limit of m( 1 )→infinite and m( 2 )→infinite, where we neglect the terms approx. 1/m( 1 ) and 1/m( 2 ). (orig./WL) [de

Exact solutions of nonlinear generalizations of the Klein Gordon and Schrodinger equations

International Nuclear Information System (INIS)

Burt, P.B.

1978-01-01

Exact solutions of sine Gordon and multiple sine Gordon equations are constructed in terms of solutions of a linear base equation, the Klein Gordon equation and also in terms of nonlinear base equations where the nonlinearity is polynomial in the dependent variable. Further, exact solutions of nonlinear generalizations of the Schrodinger equation and of additional nonlinear generalizations of the Klein Gordon equation are constructed in terms of solutions of linear base equations. Finally, solutions with spherical symmetry, of nonlinear Klein Gordon equations are given. 14 references

Five-dimensional PPN formalism and experimental test of Kaluza-Klein theory

International Nuclear Information System (INIS)

Xu Peng; Ma Yongge

2007-01-01

The parametrized post-Newtonian formalism for 5-dimensional metric theories with a compact extra dimension is developed. The relation of the 5-dimensional and 4-dimensional formulations is then analyzed, in order to compare the higher dimensional theories of gravity with experiments. It turns out that the value of post-Newtonian parameter γ in the reduced 5-dimensional Kaluza-Klein theory is two times smaller than that in 4-dimensional general relativity. The departure is due to the existence of an extra dimension in the Kaluza-Klein theory. Thus the confrontation between the reduced 4-dimensional formalism and Solar system experiments raises a severe challenge to the classical Kaluza-Klein theory

Melanie Klein and Repression: an examination of some unpublished Notes of 1934.

Science.gov (United States)

Hinshelwood, R D

2006-01-01

Fifteen pages of unpublished Notes were found in the Melanie Klein Archives dating from early 1934, a crucial moment in Klein's development. She was at this time, 1934, moving away from child analysis, whilst also rethinking and revising her allegiance to Karl Abraham's theory of the phases of libidinal development. These Notes, entitled "Early Repression Mechanism," show Klein struggling to develop what became her characteristic theories of the depressive position and the paranoid-schizoid position. Although these Notes are precursors of the paper Klein gave later to the IPA Congress in 1934, they also show the origins of the emphasis she and her followers eventually gave to "splitting" rather than repression. The Notes give us an insight into the way that she worked clinically at the time. We see Klein's confidence develop as she diverged from the classical theories and technique. Her ideas were based on close attention to the detail of her clinical material, rather than attacking theoretical problems directly. The Notes show her method of struggling to her own conclusions, and they offer us a chance to grasp the roots of the subsequent controversy over Kleinian thought.

Felix Klein and the NCTM's Standards: A Mathematician Considers Mathematics Education.

Science.gov (United States)

McComas, Kim Krusen

2000-01-01

Discusses the parallels between Klein's position at the forefront of a movement to reform mathematics education and that of the National Council of Teachers of Mathematics' (NCTM) Standards. Draws a picture of Klein as an important historical figure who saw equal importance in studying pure mathematics, applying mathematics, and teaching…

Phases of Kaluza-Klein Black Holes

DEFF Research Database (Denmark)

Harmark, Troels; Obers, N. A.

2005-01-01

We review the latest progress in understanding the phase structure of static and neutral Kaluza-Klein black holes, i.e. static and neutral solutions of pure gravity with an event horizon that asymptote to a d-dimensional Minkowski-space times a circle. We start by reviewing the (mu,n) phase diagram...... and the split-up of the phase structure into solutions with an internal SO(d-1) symmetry and solutions with Kaluza-Klein bubbles. We then discuss the uniform black string, non-uniform black string and localized black hole phases, and how those three phases are connected, involving issues such as classical...... instability and horizon-topology changing transitions. Finally, we review the bubble-black hole sequences, their place in the phase structure and interesting aspects such as the continuously infinite non-uniqueness of solutions for a given mass and relative tension....

On the formulation of the positive-energy theorem in Kaluza--Klein theories

International Nuclear Information System (INIS)

Moreschi, O.M.; Sparling, G.A.J.

1986-01-01

The positive-energy theorem is formulated in the context of Kaluza--Klein theories. Different cases are considered, including the situation in which no symmetry is assumed. This work offers a new technique for stability considerations in Kaluza--Klein theories

Kaluza-Klein theories: an overview

International Nuclear Information System (INIS)

Chodos, A.

1984-01-01

The aim of this Comment is to provide for the nonexpert a descriptive overview, colored with a certain amount of personal prejudice, of the basic ideas underlying the Kaluza-Klein approach to unification, and a very brief survey of some of the more recent developments. The treatment is nonmathematical in the extreme. (author)

New non-linear modified massless Klein-Gordon equation

Energy Technology Data Exchange (ETDEWEB)

Asenjo, Felipe A. [Universidad Adolfo Ibanez, UAI Physics Center, Santiago (Chile); Universidad Adolfo Ibanez, Facultad de Ingenieria y Ciencias, Santiago (Chile); Hojman, Sergio A. [Universidad Adolfo Ibanez, UAI Physics Center, Santiago (Chile); Universidad Adolfo Ibanez, Departamento de Ciencias, Facultad de Artes Liberales, Santiago (Chile); Universidad de Chile, Departamento de Fisica, Facultad de Ciencias, Santiago (Chile); Centro de Recursos Educativos Avanzados, CREA, Santiago (Chile)

2017-11-15

The massless Klein-Gordon equation on arbitrary curved backgrounds allows for solutions which develop ''tails'' inside the light cone and, therefore, do not strictly follow null geodesics as discovered by DeWitt and Brehme almost 60 years ago. A modification of the massless Klein-Gordon equation is presented, which always exhibits null geodesic propagation of waves on arbitrary curved spacetimes. This new equation is derived from a Lagrangian which exhibits current-current interaction. Its non-linearity is due to a self-coupling term which is related to the quantum mechanical Bohm potential. (orig.)

Cosmological production of Kaluza-Klein monopoles

International Nuclear Information System (INIS)

Harvey, J.A.; Kolb, E.W.; Perry, M.J.

1984-09-01

The cosmological production of Kaluza-Klein monopoles is discussed. The present monopole to entropy ratio is calculated in some simple models with the conclusion that this ratio is unacceptably large unless additional mechanisms for entropy production or monopole annihilation are present

The Cauchy problem for non-linear Klein-Gordon equations

International Nuclear Information System (INIS)

Simon, J.C.H.; Taflin, E.

1993-01-01

We consider in R n+1 , n≥2, the non-linear Klein-Gordon equation. We prove for such an equation that there is neighbourhood of zero in a Hilbert space of initial conditions for which the Cauchy problem has global solutions and on which there is asymptotic completeness. The inverse of the wave operator linearizes the non-linear equation. If, moreover, the equation is manifestly Poincare covariant then the non-linear representation of the Poincare-Lie algebra, associated with the non-linear Klein-Gordon equation is integrated to a non-linear representation of the Poincare group on an invariant neighbourhood of zero in the Hilbert space. This representation is linearized by the inverse of the wave operator. The Hilbert space is, in both cases, the closure of the space of the differentiable vectors for the linear representation of the Poincare group, associated with the Klein-Gordon equation, with respect to a norm defined by the representation of the enveloping algebra. (orig.)

The nonsymmetric Kaluza-Klein (Jordan-Thiry) theory in the electromagnetic case

International Nuclear Information System (INIS)

Kalinowski, M.W.

1992-01-01

We present the nonsymmetric Kaluza-Klein and Jordan-Thiry theories as interesting propositions of physics in higher dimensions. We consider the five-dimensional (electromagnetic) case. The work is devoted to a five-dimensional unification of the NGT (nonsymmetric theory of gravitation), electromagnetism, and scalar forces in a Jordan-Thiry manner. We find open-quotes interference effectsclose quotes between gravitational and electromagnetic fields which appear to be due to the skew-symmetric part of the metric. Our unification, called the nonsymmetric Jordan-Thiry theory, becomes the classical Jordan-Thiry theory if the skew-symmetric part of the metric is zero. It becomes the classical Kaluza-Klein theory if the scalar field ρ=1 (Kaluza's Ansatz). We also deal with material sources in the nonsymmetric Kaluza-Klein theory for the electromagnetic case. We consider phenomenological sources with a nonzero fermion current, a nonzero electric current, and a nonzero spin density tensor. From the Palatini variational principle we find equations for the gravitational and electromagnetic fields. We also consider the geodetic equations in the theory and the equation of motion for charged test particles. We consider some numerical predictions of the nonsymmetric Kaluza-Klein theory with nonzero (and with zero) material sources. We prove that they do not contradict any experimental data for the solar system and on the surface of a neutron star. We deal also with spin sources in the nonsymmetric Kaluza-Klein theory. We find an exact, static, spherically symmetric solution in the nonsymmetric Kaluza-Klein theory in the electromagnetic case. This solution has the remarkable property of describing open-quotes mass without massclose quotes and open-quotes charge without charge.close quotes We examine its properties and a physical interpretation. 91 refs., 7 figs

A Klein-tunneling transistor with ballistic graphene

Energy Technology Data Exchange (ETDEWEB)

Wilmart, Quentin; Fève, Gwendal; Berroir, Jean-Marc; Plaçais, Bernard [Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS (UMR 8551), Université P et M Curie, Université D Diderot, 24, rue Lhomond, 75231 Paris Cedex 05 (France); Berrada, Salim; Hung Nguyen, V; Dollfus, Philippe [Institute of Fundamental Electronics, Univ. Paris-Sud, CNRS, Orsay (France); Torrin, David [Département de Physique, Ecole Polytechnique, 91128 Palaiseau (France)

2014-06-15

Today, the availability of high mobility graphene up to room temperature makes ballistic transport in nanodevices achievable. In particular, p-n-p transistors in the ballistic regime give access to Klein tunneling physics and allow the realization of devices exploiting the optics-like behavior of Dirac Fermions (DFs) as in the Veselago lens or the Fabry–Pérot cavity. Here we propose a Klein tunneling transistor based on the geometrical optics of DFs. We consider the case of a prismatic active region delimited by a triangular gate, where total internal reflection may occur, which leads to the tunable suppression of transistor transmission. We calculate the transmission and the current by means of scattering theory and the finite bias properties using non-equilibrium Green's function (NEGF) simulation. (letter)

In-filled reservoirs serving as sediment archives to analyse soil organic carbon erosion – Taking a closer look at the Karoo rangelands

DEFF Research Database (Denmark)

Krenz, Juliane; Greenwood, Philip; Kuhn, Brigitte

The semi-arid rangelands of the Great Karoo region in South Africa, which are nowadays characterized by badlands on the foot slopes of upland areas and complex gully systems in valley bottoms, have experienced a number of environmental changes. With the settlement of European farmers in the late ......th century agricultural activities increased, leading to overgrazing which probably acted as a trigger to land degradation. As a consequence of higher water demands and shifting rainfall patterns, many dams and small reservoirs have been constructed to provide drinking water for cattle...... or to facilitate irrigation during dry periods. Most of these dams are now filled with sediment and many have become breached, revealing sediment archives that can be used to analyse land use changes as well as carbon erosion and deposition during the last ca. 100 years. In this ongoing project, a combination...

Dispersive estimates for the Schroedinger and Klein-Gordon equations

Energy Technology Data Exchange (ETDEWEB)

Kopylova, Elena A [Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow (Russian Federation)

2010-01-01

This is a survey of results on the long-time asymptotic behaviour of solutions of the Schroedinger and Klein-Gordon equations in weighted energy norms. Results obtained from 1975 to 2001 in the spectral scattering theory of Agmon, Jensen-Kato, Jensen-Nenciu, and Murata are described for the Schroedinger equation, along with the author's recent results obtained jointly with A.I. Komech for the Klein-Gordon equation. The methods used develop the spectral approach as applied to relativistic equations. Bibliography: 40 titles.

KLEIN: Coulomb functions for real lambda and positive energy to high accuracy

International Nuclear Information System (INIS)

Barnett, A.R.

1981-01-01

KLEIN computes relativistic Schroedinger (Klein-Gordon) equation solutions, i.e. Coulomb functions for real lambda > - 1, Fsub(lambda)(eta,x), Gsub(lambda)(eta,x), F'sub(lambda)(eta,x) and G'sub(lambda)(eta,x) for real kappa > 0 and real eta, - 10 4 4 . Hence it is also suitable for Bessel and spherical Bessel functions. Accuracies are in the range 10 -14 -10 -16 in oscillating region, and approx. equal to 10 -30 on an extended precision compiler. The program is suitable for generating Klein-Gordon wavefunctions for matching in pion and kaon physics. (orig.)

Vicious circles of punishment: a reading of Melanie Klein's Envy and gratitude.

Science.gov (United States)

Smith, Henry F

2008-01-01

Staged as a moral drama, Melanie Klein's Envy and Gratitude (1957) straddles two eras: one reflecting a simpler more concrete, historical method, and the other an approach of greater complexity, focused on the transferential moment. Embedded within the transference are the vicious circles of envy and punishment that are the hallmark of Klein's text. Punishment itself which is always punishment of both self and other, creates its own vicious circle, set in motion by a single act. In the sadomasochistic enactments that result, the moral force of Klein's categories fuels the countertransference. A detailed clinical hour is presented.

Considerations on the hyperbolic complex Klein-Gordon equation

International Nuclear Information System (INIS)

Ulrych, S.

2010-01-01

This article summarizes and consolidates investigations on hyperbolic complex numbers with respect to the Klein-Gordon equation for fermions and bosons. The hyperbolic complex numbers are applied in the sense that complex extensions of groups and algebras are performed not with the complex unit, but with the product of complex and hyperbolic unit. The modified complexification is the key ingredient for the theory. The Klein-Gordon equation is represented in this framework in the form of the first invariant of the Poincare group, the mass operator, in order to emphasize its geometric origin. The possibility of new interactions arising from hyperbolic complex gauge transformations is discussed.

Hidden symmetries of Kaluza-Klein theories

International Nuclear Information System (INIS)

Popov, A.D.

1987-01-01

It is shown that the introduction of dynamical torsion in Kaluza-Klein theories makes it possible to increase the number of gauge fields extracted from the Lagrangian without increasing the number of additional dimensions. An example of spontaneous compactification of a studied model is considered

Os anulabilismos de Klein e de Swain e o problema de Gettier

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Emerson Carlos Valcarenghi

2010-08-01

Full Text Available In this essay, we intend to show that Peter Klein and Marshall Swain defeasibility theories do not resolve the Gettier problem. Klein postulates, to any Gettier counterexample, that there is a true proposition which, when associated with evidence-e of S, genuinely defeats the justification of p to S. Swain postulates that, to any Gettier-type counterexample, there is a true proposition which, when associated with the set of reasons-R of S, ultimately defeats the justification of S to believe p. To show that Klein an Swain proposals do not resolve that problem, this essay presents two Gettier-type counterexamples for which there are no genuine defeaters of justification of p by e to S and there are no defeaters not ultimately defeated of the justification of the belief of S that p by R. After doing that, we try to show that the obtained conclusion regarding Klein and Swain defeasibility theories can be extended to any defeasibility theory of knowledge.

On classical solutions of the relativistic Vlasov-Klein-Gordon system

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Michael Kunzinger

2005-01-01

Full Text Available We consider a collisionless ensemble of classical particles coupled with a Klein-Gordon field. For the resulting nonlinear system of partial differential equations, the relativistic Vlasov-Klein-Gordon system, we prove local-in-time existence of classical solutions and a continuation criterion which says that a solution can blow up only if the particle momenta become large. We also show that classical solutions are global in time in the one-dimensional case.

Charged particles as Kaluza-Klein monopoles

International Nuclear Information System (INIS)

Chan, H.-M.; Tsou, S.T.

1984-05-01

The authors describe some explorations into the possibility of treating charged particles as monopoles in a Kaluza-Klein world. Such considerations may be useful in the future for constructing model theories in which both matter and gauge structure emerge as consequences of space-time geometry. (author)

A Klein-tunneling transistor with ballistic graphene

International Nuclear Information System (INIS)

Wilmart, Quentin; Fève, Gwendal; Berroir, Jean-Marc; Plaçais, Bernard; Berrada, Salim; Hung Nguyen, V; Dollfus, Philippe; Torrin, David

2014-01-01

Today, the availability of high mobility graphene up to room temperature makes ballistic transport in nanodevices achievable. In particular, p-n-p transistors in the ballistic regime give access to Klein tunneling physics and allow the realization of devices exploiting the optics-like behavior of Dirac Fermions (DFs) as in the Veselago lens or the Fabry–Pérot cavity. Here we propose a Klein tunneling transistor based on the geometrical optics of DFs. We consider the case of a prismatic active region delimited by a triangular gate, where total internal reflection may occur, which leads to the tunable suppression of transistor transmission. We calculate the transmission and the current by means of scattering theory and the finite bias properties using non-equilibrium Green's function (NEGF) simulation. (letter)

Holographic duals of Kaluza-Klein black holes

International Nuclear Information System (INIS)

Azeyanagi, Tatsuo; Ogawa, Noriaki; Terashima, Seiji

2009-01-01

We apply Brown-Henneaux's method to the 5D extremal rotating Kaluza-Klein black holes essentially following the calculation of the Kerr/CFT correspondence, which is not based on supersymmetry nor string theory. We find that there are two completely different Virasoro algebras that can be obtained as the asymptotic symmetry algebras according to appropriate boundary conditions. The microscopic entropies are calculated by using the Cardy formula for both boundary conditions and they perfectly agree with the Bekenstein-Hawking entropy. The rotating Kaluza-Klein black holes contain a 4D dyonic Reissner-Nordstroem black hole and Myers-Perry black hole. Since the D-brane configurations corresponding to these black holes are known, we expect that our analysis will shed some light on deeper understanding of chiral CFT 2 's dual to extremal black holes.

Realization of a unique time evolution unitary operator in Klein Gordon theory

International Nuclear Information System (INIS)

Balasubramanian, T.S.; Bhatia, S.Kr.

1986-01-01

The scattering theory for the Klein Gordon equation, with time-dependent potential and in a non-static space-time, is considered. Using the Klein Gordon equation formulated in the Hilbert space L 2 (R 3 ) and the Einstein's relativistic equation in the space L 2 (R 3 ,dx) and establishing the equivalence of the vacuum states of their linearized forms in the Hilbert space L 2 (R 3 ) with the help of unique symmetric symplectic operator, the time evolution unitary operator U(t) has been fixed for the Klein Gordon eqution, incorporating either the positive or negative frequencies, in the infinite dimensional Hilbert space L 2 (R 3 ). (author)

Fractional Klein-Gordon equation composed of Jumarie fractional derivative and its interpretation by a smoothness parameter

Science.gov (United States)

Ghosh, Uttam; Banerjee, Joydip; Sarkar, Susmita; Das, Shantanu

2018-06-01

Klein-Gordon equation is one of the basic steps towards relativistic quantum mechanics. In this paper, we have formulated fractional Klein-Gordon equation via Jumarie fractional derivative and found two types of solutions. Zero-mass solution satisfies photon criteria and non-zero mass satisfies general theory of relativity. Further, we have developed rest mass condition which leads us to the concept of hidden wave. Classical Klein-Gordon equation fails to explain a chargeless system as well as a single-particle system. Using the fractional Klein-Gordon equation, we can overcome the problem. The fractional Klein-Gordon equation also leads to the smoothness parameter which is the measurement of the bumpiness of space. Here, by using this smoothness parameter, we have defined and interpreted the various cases.

Nonlinear Klein-Gordon soliton mechanics

International Nuclear Information System (INIS)

Reinisch, G.

1992-01-01

Nonlinear Klein-Gordon solitary waves - or solitons in a loose sense - in n+1 dimensions, driven by very general external fields which must only satisfy continuity - together with regularity conditions at the boundaries of the system, obey a quite simple equation of motion. This equation is the exact generalization to this dynamical system of infinite number of degrees of freedom - which may be conservative or not - of the second Newton's law setting the basis of material point mechanics. In the restricted case of conservative nonlinear Klein-Gordon systems, where the external driving force is derivable from a potential energy, we recover the generalized Ehrenfest theorem which was itself the extension to such systems of the well-known Ehrenfest theorem in quantum mechanics. This review paper first displays a few (of one-dimensional sine-Gordon type) typical examples of the basic difficulties related to the trial construction of solitary-waves is proved and the derivation of the previous sine-Gordon examples from this theorem is displayed. Two-dimensional nonlinear solitary-wave patterns are considered, as well as a special emphasis is put on the applications to space-time complexity of 1-dim. sine-Gordon systems

Melanie Klein and Anna Freud: the discourse of the early dispute.

Science.gov (United States)

Viner, R

1996-01-01

Divisions in the field of the psychoanalysis of children can be traced to a dispute over the infantile super-ego between the theorists Melanie Klein and Anna Freud beginning in 1927. These divisions are understood within the analytic world as the result of scientific disputation between alternative valid theories. An examination of the language, claims, and epistemology of Klein's and Freud's publications in 1927 that marked the public commencement of the conflict, reveals a personalized discourse in which authority was derived from the allegiance, experience, and personal analytic standing of the contestants as much as from theoretical insight. The structure and rhetoric of the debate suggest that, rather than terminating the dispute, the publications of 1927 served to encourage professionalization in child analysis and establish Anna Freud and Melanie Klein as authoritative alternative theorists.

Melanie Klein, una princesa que creó su propio reino

OpenAIRE

Sánchez-Barranco Ruiz, Antonio; Vallejo Orellana, Reyes

2004-01-01

Las formulaciones kleinianas no pueden ser encuadradas como un mero desarrollo del psicoanálisis freudiano, dado que suponen cambios radicales en su metapsicología, núcleo intocable del sistema. En todo caso, Melanie Klein merece un lugar de privilegio entre las mujeres pioneras que aportaron ideas originales a la psicología del inconsciente y aunque siempre se autoconsideró una fiel seguidora de Freud, terminó desarrollando su propio reino. Melanie Klein's formulations should not be frame...

Rezension zu: Julia Kristeva: Das weibliche Genie – Melanie Klein. Gießen: Psychosozial-Verlag 2008

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Lilli Gast

2009-07-01

Full Text Available Julia Kristeva widmet sich im zweiten Teil ihrer Trilogie über das weibliche Genie dem Leben und Werk von Melanie Klein, die mit ihren Arbeiten über die früheste Verfasstheit des Psychischen das psychoanalytische Denken für die Psychosen und den Wahn aufschloss und die Rolle des Mütterlichen im psychoanalytischen Diskurs neu definierte. In ihrer Auseinandersetzung mit Klein gelingt Kristeva nicht nur eine ausgesprochen gelungene Einführung in Kleins Denken, sondern auch eine Analyse weiblicher Intellektualität im 20. Jahrhundert. Zudem werden die Schnittstellen im Denken Kleins und Kristevas sichtbar.

Kaluza-Klein theories and the space-time signature

International Nuclear Information System (INIS)

Aref'eva, I.Y.; Volovich, I.V.

1985-01-01

Vacuum solutions in Kaluza-Klein theories are constructed with additional compactified time dimensions, for which the zeroth-order modes do not contain ghosts. Compact spaces of negative curvature are used

Klein tunneling in the α -T3 model

Science.gov (United States)

Illes, E.; Nicol, E. J.

2017-06-01

We investigate Klein tunneling for the α -T3 model, which interpolates between graphene and the dice lattice via parameter α . We study transmission across two types of electrostatic interfaces: sharp potential steps and sharp potential barriers. We find both interfaces to be perfectly transparent for normal incidence for the full range of the parameter α for both interfaces. For other angles of incidence, we find that transmission is enhanced with increasing α . For the dice lattice, we find perfect, all-angle transmission across a potential step for incoming electrons with energy equal to half of the height of the potential step. This is analogous to the "super", all-angle transmission reported for the dice lattice for Klein tunneling across a potential barrier.

Do South African Consumers have an Appetite for an Origin-based Certification System for Meat Products? A Synthesis of Studies on Perceptions, Preferences and Experiments

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Johann F. Kirsten

2017-01-01

Full Text Available The introduction of Protected Designation of Origin (PDO type certification schemes in countries outside Europe is a recent phenomenon as the philosophy of origin based foods obtains global traction. It is therefore interesting to understand whether consumers in these countries have a similar appreciation for these certification schemes and whether they are willing to pay a premium if the origin of the product is guaranteed. The Karoo Lamb case in South Africa provides an ideal opportunity to explore this question. At the same time the paper illustrates that the results and interpretation of consumer studies are sensitive to the methodology applied. We illustrate this argument by benefitting from a range of consumer studies that was undertaken over a period of five years in order to understand the South African consumers’ perceptions about the Karoo region and their preferences and willingness to pay for the meat product from the Karoo. The studies which we compare and synthesise in this paper used different techniques such as perception analysis; stated preference methods (through a conjoint analysis; and a range of revealed preference methods including, an experimental auction and a retail store experiment. In essence the paper synthesises and compares the results from the different studies and illustrates how different techniques bring different results and conclusions. We then try to establish whether there is consistency in the results across methods to help us getting to a conclusive position on the consumer value of this product. From these results we are able – in a more comprehensive way - to tell whether PDO-type products are likely to be of value to South African consumers.

Reduced thalamic and pontine connectivity in Kleine-Levin syndrome

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Maria eEngström

2014-04-01

Full Text Available The Kleine-Levin syndrome is a rare sleep disorder, characterized by exceptionally long sleep episodes. The neuropathology of the syndrome is unknown and treatment is often inadequate. The aim of the study was to improve understanding of the underlying neuropathology, related to cerebral networks, in Kleine-Levin syndrome during sleep episodes. One patient with Kleine-Levin syndrome and congenital nystagmus, was investigated by resting state functional Magnetic Resonance Imaging during both asymptomatic and hypersomnic periods. Fourteen healthy subjects were also investigated as control samples. Functional connectivity was assessed from seed regions of interest in the thalamus and the dorsal pons. Thalamic connectivity was normal in the asymptomatic patient whereas the connectivity between the brain stem, including dorsal pons, and the thalamus was diminished during hypersomnia. These results suggest that the patient’s nystagmus and hypersomnia might have their pathological origin in adjacent dorsal pontine regions. This finding provides additional knowledge of the cerebral networks involved in the neuropathology of this disabling disorder. Furthermore, these findings regarding a rare syndrome have broad implications and results could be of interest to researchers and clinicians in the whole field of sleep medicine.

A Krein quantization approach to Klein paradox

International Nuclear Information System (INIS)

Payandeh, Farrin; Fathi, Mohsen; Mohammad Pur, Toradj; Moghaddam, Zahra Gh.

2013-01-01

In this paper we first introduce the famous Klein paradox. Afterwards by proposing the Krein quantization approach and taking the negative modes into account, we will show that the expected and exact current densities could be achieved without confronting any paradox. (authors)

The origin of the logic of symbolic mathematics Edmund Husserl and Jacob Klein

CERN Document Server

Hopkins, Burt C

2011-01-01

Burt C. Hopkins presents the first in-depth study of the work of Edmund Husserl and Jacob Klein on the philosophical foundations of the logic of modern symbolic mathematics. Accounts of the philosophical origins of formalized concepts-especially mathematical concepts and the process of mathematical abstraction that generates them-have been paramount to the development of phenomenology. Both Husserl and Klein independently concluded that it is impossible to separate the historical origin of the thought that generates the basic concepts of mathematics from their philosophical meanings. Hopkins explores how Husserl and Klein arrived at their conclusion and its philosophical implications for the modern project of formalizing all knowledge.

Good and Bad: Love and Intimacy From Plato to Melanie Klein.

Science.gov (United States)

Stromberg, David

2018-06-01

Melanie Klein's theories on love outline a complex system of relations-an oscillating dynamic of psychical and emotional tendencies following from both actual experience and fantasies produced by the mind. Her insights are often discussed and applied in psychoanalytical contexts, but the philosophical implications of her theory-especially in relation to Platonic thought-have rarely been discussed. In this article, I will attempt to address this gap by setting out some preliminary yet core considerations shared by both Plato and Klein. First, I will describe some structural parallels between Kleinian and Platonic thought, especially in dialectical terms. Second, I will outline Plato's covert influence on Freud as passing through the teachings of philosopher Franz Brentano. And last, I will discuss intimacy as a struggle between the forces of good and bad, creativity and destruction, and love and hate-suggesting that Klein's conception of love emerges as a moral exigency.

Maps compiled by the ESSO Minerals Company during their exploration program for uranium in South Africa

International Nuclear Information System (INIS)

Bertolini, A.; Pretorius, L.; Weideman, M.; Scheepers, T.

1985-09-01

The report is a bibliography of approximately one thousand maps. The maps contain information of ESSO Minerals Company's prospecting activities for mainly uranium in South Africa. ESSO explorated for uranium in the Karoo, Northwestern Cape and the Bushveld. The bibliography contains two indexes. The one is a list of prospects and projects as per geological province and the other is an alphabetic list of projects and prospects. Three geological provinces are distiguished, namely, the Bushveld province, Karoo province and Namaqualand province. The annotations contain information on the location and geographic area of the map, the name of the project or prospect, the title, a statement of resposibility (this includes the compiles i.e. geologists, and/or draftsmen), the statement of scale which is always expressed as a ratio, the date of compilation and/or revision and a few keywords to indicate the topical subject matter

Symmetry in Kaluza-Klein theory

International Nuclear Information System (INIS)

Strathdee, J.

1982-12-01

A method is described for making harmonic expansions on the internal space of a Kaluza-Klein vacuum in cases where this space is a coset space. This method fully exploits the symmetry of the space and should be useful for the analysis of excitation spectra and, in particular, for constructing the correct zero-mode ansatz in cases where the multi-dimensional gravitational fields are coupled to matter fields of various kinds. (author)

Freud and Klein on the concept of phantasy.

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Spillius, E B

2001-04-01

In summary, I think Freud's idea is that the prime mover of psychic life is the unconscious wish, not phantasy. The 'work' of making phantasies and the 'work' of making dreams are parallel processes in which forbidden unconscious wishes achieve disguised expression and partial fulfilment. For Freud himself, especially in his central usage, and even more for his immediate followers, phantasies are conceived as imagined fulfilments of frustrated wishes. Whether they originate in the system conscious or the system preconscious, they are an activity of the ego and are formed according to the principles of the secondary process. That is not the whole story, however, because phantasies may get repressed into the system unconscious, where they become associated with the instinctual wishes, become subject to the laws of the primary process, and may find their way into dreams and many other derivatives. For Freud and for French psychoanalysts particularly, there are the primal phantasies, 'unconscious all along', of the primal scene, castration and seduction, also capable of being directly incorporated into dreams and expressed through other derivatives. For Klein phantasy is an even more central concept than for Freud and it has continued to be used by her successors with only minor changes. In Klein's thinking unconscious phantasies play the part that Freud assigned to the unconscious wish. They underlie dreams rather than being parallel to them--a much more inclusive definition of phantasy than Freud's. The earliest and most deeply unconscious phantasies are bodily, and only gradually, with maturation and developing experience through introjection and projection do some of them come to take a verbal form. Freud's central usage, the wish-fulfilling definition of phantasy, is a particular type of phantasy within Klein's more inclusive definition. And, as in Freud's formulation, conscious phantasies may be repressed, but in Klein's formulation this is not the only or even

Supersymmetry: Kaluza-Klein theory, anomalies, and superstrings

International Nuclear Information System (INIS)

Aref'eva, I.Y.; Volovich, I.V.

1985-01-01

Progress in the search for a unified theory of elementary particles is reviewed. The supersymmetrical Kaluza-Klein theories are described: 11-, 10-, and 6-dimensional models of supergravity. The methods of spontaneous compactification, with whose help the four-dimensional theories are obtained, are described. The properties of the massless sector: zero modes in the Kaluza-Klein theories: and the question of the stability of vacuum solutions are discussed. An important criterion for the selection of a self-consistent theory is the absence of anomalies. The basic formulas for multidimensional chiral and gravitational anomalies are presented. The mechanism of the cancellation of the anomaly for Green and Schwarz's 10-dimensional effective field theory of superstrings with the gauge groups SO(32) and E 8 x E 8 is described. The basic concepts and the results of the theory of superstrings are presented. This theory has no divergences and is at the present time a very attractive candidate for a unified theory of elementary particles

Fermionic dimensions and Kaluza-Klein theory

International Nuclear Information System (INIS)

Delbourgo, R.; Zhang, R.B.

1988-01-01

Instead of appending extra bosonic dimensions to spacetime and needing to exorcise the higher modes, it is possible to construct Kaluza-Klein models in which the additional coordinates are fermionic and the higher modes do not arise. We erect a unified gravity/Yang-Mills theory on such a grassmannian framework and then discuss possible generalisations to other internal groups. (orig.)

Localized solutions of non-linear Klein--Gordon equations

International Nuclear Information System (INIS)

Werle, J.

1977-05-01

Nondissipative, stationary solutions for a class of nonlinear Klein-Gordon equations for a scalar field were found explicitly. Since the field is different from zero only inside a sphere of definite radius, the solutions are called quantum droplets

Aspects of quasi-Riemannian Kaluza-Klein theory

International Nuclear Information System (INIS)

Viswanathan, K.S.; Wong, B.

1985-01-01

We consider the applications of quasi-Riemannian geometry in Kaluza-Klein theories. We find that such theories cannot be implemented for all choices of the tangent group G/sub T/ and internal space G/H for reasons of gauge invariance. Coupling of fermions to gravity poses further problems in these theories

Klein-Gordon oscillator with position-dependent mass in the rotating cosmic string spacetime

Science.gov (United States)

Wang, Bing-Qian; Long, Zheng-Wen; Long, Chao-Yun; Wu, Shu-Rui

2018-02-01

A spinless particle coupled covariantly to a uniform magnetic field parallel to the string in the background of the rotating cosmic string is studied. The energy levels of the electrically charged particle subject to the Klein-Gordon oscillator are analyzed. Afterwards, we consider the case of the position-dependent mass and show how these energy levels depend on the parameters in the problem. Remarkably, it shows that for the special case, the Klein-Gordon oscillator coupled covariantly to a homogeneous magnetic field with the position-dependent mass in the rotating cosmic string background has the similar behaviors to the Klein-Gordon equation with a Coulomb-type configuration in a rotating cosmic string background in the presence of an external magnetic field.

Klein-Weyl's program and the ontology of gauge and quantum systems

Science.gov (United States)

Catren, Gabriel

2018-02-01

We distinguish two orientations in Weyl's analysis of the fundamental role played by the notion of symmetry in physics, namely an orientation inspired by Klein's Erlangen program and a phenomenological-transcendental orientation. By privileging the former to the detriment of the latter, we sketch a group(oid)-theoretical program-that we call the Klein-Weyl program-for the interpretation of both gauge theories and quantum mechanics in a single conceptual framework. This program is based on Weyl's notion of a "structure-endowed entity" equipped with a "group of automorphisms". First, we analyze what Weyl calls the "problem of relativity" in the frameworks provided by special relativity, general relativity, and Yang-Mills theories. We argue that both general relativity and Yang-Mills theories can be understood in terms of a localization of Klein's Erlangen program: while the latter describes the group-theoretical automorphisms of a single structure (such as homogenous geometries), local gauge symmetries and the corresponding gauge fields (Ehresmann connections) can be naturally understood in terms of the groupoid-theoretical isomorphisms in a family of identical structures. Second, we argue that quantum mechanics can be understood in terms of a linearization of Klein's Erlangen program. This stance leads us to an interpretation of the fact that quantum numbers are "indices characterizing representations of groups" ((Weyl, 1931a), p.xxi) in terms of a correspondence between the ontological categories of identity and determinateness.

Proton-transfer reaction mass spectrometry (PTR-MS) for the authentication of regionally unique South African lamb.

Science.gov (United States)

Erasmus, Sara W; Muller, Magdalena; Alewijn, Martin; Koot, Alex H; van Ruth, Saskia M; Hoffman, Louwrens C

2017-10-15

The volatile fingerprints of South African lamb meat and fat were measured by proton-transfer mass spectrometry (PTR-MS) to evaluate it as an authentication tool. Meat and fat of the Longissimus lumborum (LL) of lambs from six different regions were assessed. Analysis showed that the volatile fingerprints were affected by the origin of the meat. The classification of the origin of the lamb was achieved by examining the calculated and recorded fingerprints in combination with chemometrics. Four different partial least squares discriminant analysis (PLS-DA) models were fitted to the data to classify lamb meat and fat samples into "region of origin" (six different regions) and "origin" (Karoo vs. Non-Karoo). The estimation models classified samples 100% correctly. Validation of the first two models gave 42% (fat) and 58% (meat) correct classification of region, while the second two models performed better with 92% (fat) and 83% (meat) correct classification of origin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chiral tunnelling and the Klein paradox in graphene

NARCIS (Netherlands)

Katsnelson, M.I.; Novoselov, K.S.; Geim, A.K.

2006-01-01

The so-called Klein paradox - unimpeded penetration of relativistic particles through high and wide potential barriers - is one of the most exotic and counterintuitive consequences of quantum electrodynamics. The phenomenon is discussed in many contexts in particle, nuclear and astro-physics but

Cosmological applications in Kaluza—Klein theory

International Nuclear Information System (INIS)

Wanas, M.I.; Nashed, Gamal G. L.; Nowaya, A.A.

2012-01-01

The field equations of Kaluza—Klein (KK) theory have been applied in the domain of cosmology. These equations are solved for a flat universe by taking the gravitational and the cosmological constants as a function of time t. We use Taylor's expansion of cosmological function, Λ(t), up to the first order of the time t. The cosmological parameters are calculated and some cosmological problems are discussed. (geophysics, astronomy, and astrophysics)

Chaos in Kaluza-Klein models

Energy Technology Data Exchange (ETDEWEB)

Elskens, Yves; Henneaux, Marc

1987-09-01

Kaluza-Klein cosmological models are investigated in the vicinity of a spacelike singularity. A new parametrisation of the Kasner exponents is given for any spacetime dimension, which reduces the mixmaster dynamics to a combination of a translation and an isometry or a dilating inversion. Using this parametrisation, chaos is proven to hold for spacetime dimension n <= 10. For n >= 11, the chaotic behaviour is shown to become unstable and to be replaced by monotonic Kasner asymptotics. These results explicitly establish conjectures formulated in previous work.

An early geikiid dicynodont from the Tropidostoma Assemblage Zone (late Permian of South Africa

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Christian F. Kammerer

2017-01-01

Full Text Available Based on specimens previously identified as Tropidostoma, a new taxon of dicynodont (Bulbasaurus phylloxyron gen. et sp. nov. from the Karoo Basin of South Africa is described. Bulbasaurus is a medium-sized dicynodont (maximum dorsal skull length 16.0 cm restricted to the Tropidostoma Assemblage Zone (early Lopingian of the Beaufort Group. Bulbasaurus can be distinguished from Tropidostoma by an array of characters including the presence of a tall, sharp premaxillary ridge, large, rugose, nearly-confluent nasal bosses, a nasofrontal ridge, massive tusks, robust pterygoids, prominently twisted subtemporal bar, and absence of a distinct postfrontal. Inclusion of Bulbasaurus in a phylogenetic analysis of anomodont therapsids recovers it as a member of Geikiidae, a clade of otherwise later Permian dicynodonts such as Aulacephalodon and Pelanomodon. Bulbasaurus exhibits many of the characters typical of adult Aulacephalodon, but at substantially smaller skull size (these characters are absent in comparably-sized Aulacephalodon juveniles, suggesting that the evolution of typical geikiid morphology preceded gigantism in the clade. Bulbasaurus is the earliest known geikiid and the only member of the group known from the Tropidostoma Assemblage Zone; discovery of this taxon shortens a perplexing ghost lineage and indicates that abundant clades from the later Permian of South Africa (e.g., Geikiidae, Dicynodontoidea may have originated as rare components of earlier Karoo assemblage zones.

Hidden symmetries of the Kaluza-Klein-type theories

International Nuclear Information System (INIS)

Popov, A.D.

1987-01-01

It is shown that introduction of dynamical torsion in Kaluza-Klein theories makes is possible to increase the number of gauge fields extracted from the Lagrangian without increasing the number of extra dimentions. An example of spontaneous compactification of the model investigated is considered

Oscillating particle-like solutions of nonlinear Klein-Gordon equation

International Nuclear Information System (INIS)

Bogolubsky, I.L.

1976-01-01

A denumerable set of oscillating spherically-symmetric particle-like solutions of the Klein-Gordon equation with cubic nonlinearity is found. Extended particles modelled by them turn out to be slightly radiating and long-lived

Relativistic supersymmetric quantum mechanics based on Klein-Gordon equation

International Nuclear Information System (INIS)

Znojil, Miloslav

2004-01-01

Witten's the non-relativistic formalism of supersymmetric quantum mechanics was based on a factorization and partnership between Schroedinger equations. We show how it accommodates a transition to the partnership between relativistic Klein-Gordon equations

National trauma work and the depiction of women in two Afrikaans historical Karoo novels: Fiela’s child and Sorg

Directory of Open Access Journals (Sweden)

Belinda Du Plooy

2014-02-01

Full Text Available Fiela’s child and Sorg are two female-authored popular Afrikaans novels that entertain as subtext dynamics of female agency in the same region and historical period, namely the Little Karoo of the late 19th century. The two novels present a pertinent counter-discursive paradigm to the more mainstream master narrative representations of women of the time. The novels were written and published during the late-apartheid and early post-apartheid years, 1985 and 2006, respectively, and as a result of these dynamics of production, they also engage with the socio-politics of this time, maybe even more so than with the British imperial colonialist period in which the novels are set. As such, both novels step into the discursive streams that flow in and around the trauma work that is associated with South Africa’s contemporary engagement with its colonial and apartheid legacies and heritage. Both texts also contribute to the creation and popularisation of new national master narratives. It is then in this context that these texts can be seen as participating in the multivocal discursive project of new identity construction, specifically identity construction through the writing of a new heterogeneous national autobiography.

Some technical implications of Klein's concept of 'premature ego development'.

Science.gov (United States)

Mitrani, Judith L

2007-08-01

In this paper, the author revisits the problem of 'premature ego development' first introduced by Melanie Klein in 1930. She also highlights several developments in post-Kleinian thinking since the publication of that paper, which can be seen as offshoots of or complements to Klein's work. The author proposes a link between this category of precocious development and the absence of the experience of what Bion termed the 'containing object.' She puts forward several technical considerations relevant to analytic work with patients who suffer as a result of early developmental failures and presents various clinical vignettes in order to demonstrate the ways in which these considerations take shape in the analytic setting.

The Framing of Calvin Klein: A Frame Analysis of Media Discourse about the August 1995 Calvin Klein Jeans Advertising Campaign.

Science.gov (United States)

Tucker, Lauren R.

1998-01-01

Deconstructs the "kiddie porn" media frame used by the industry and mainstream media to characterize Klein's ad campaign. Extends scholarship on the construction of youth in the media, showing how the kiddie-porn frame produces and reproduces common-sense beliefs about the nature of youth. Suggests a metadiscourse encompassing the…

Approche Kaluza-Klein et Supersymetrie de Jauge

Science.gov (United States)

Pare, Jean-Pierre

This thesis presents a non-Abelian gauge-supersymmetric Kaluza-Klein approach for charged spinning particles and strings in a background of gravitational and Yang-Mills fields. In the classical Kaluza-Klein approach, the basic mathematical structure is a principal bundle of which the base manifold is space-time. This principal bundle is endowed with a pseudo-Riemannian metric, invariant under the action of the structural group of the bundle, and a connection. Geodesic equations on the bundle lead to the Maxwell-Lorentz equation for curved space-time and Yang -Mills fields, and to a conservation law of a non-Abelian (bosonic) charge. This conservation law originates from the invariance of the free-particle action on the bundle under the action of the structural group of the bundle (gauge group). Firstly, we generalize this approach for a spinning particle. The spin of the particle is described by Grassmannian variables added to the principal bundle. This supersymmetrization gives rise, in addition to the bosonic non-Abelian charge, a fermionic one. This leads to a search for a supergroup action on the superprincipal bundle which leaves invariant the action of the spinning particle. The invariance of this action would lead to the conservation of a non-Abelian super-charge, generalizing the conservation law obtained for particles without spin. We present Lagrangian and Hamiltonian formulations, both invariant under a super -group action. The equations of motion are derived and discussed. Different terms in these equations are well known in the literature. The invariance of these formulations under a supergroup action leads to a conservation law of a non-Abelian supercharge. The bosonic part of this supercharge corresponds to the non-Abelian (bosonic) charge obtained for a particle without spin. The fermionic part is a non -physical charge. It turns out in the supersymmetric case that this decouples from all other dynamical variables, and hence it does not influence

Proper-time quantum-mechanics and the Klein paradox

International Nuclear Information System (INIS)

Thaller, B.

1981-01-01

Scattering at high potential-steps is treated in the framework of relativistic proper-time theory. No paradox arises in contrast to Dirac's wavemechanics (''Klein's paradox''); pair creation may happen with a certain probability and may be described as a scattering process with ordinary quantum-mechanical methods. (author)

Some applications on tangent bundle with Kaluza-Klein metric

Directory of Open Access Journals (Sweden)

Murat Altunbaş

2017-01-01

Full Text Available In this paper, differential equations of geodesics; parallelism, incompressibility and closeness conditions of the horizontal and complete lift of the vector fields are investigated with respect to Kaluza-Klein metric on tangent bundle.

Assessing the reactivation potential of pre-existing fractures in the southern Karoo, South Africa: Evaluating the potential for sustainable exploration across its Critical Zone

Science.gov (United States)

Dhansay, Taufeeq; Navabpour, Payman; de Wit, Maarten; Ustaszewski, Kamil

2017-10-01

Understanding the kinematics of pre-existing fractures under the present-day stress field is an indispensable prerequisite for hydraulically increasing fracture-induced rock permeability, i.e. through hydraulic stimulation, which forms the basis of economically viable exploitation of resources such as natural gas and geothermal energy. Predicting the likelihood of reactivating pre-existing fractures in a target reservoir at particular fluid injection pressures requires detailed knowledge of the orientations and magnitudes of the prevailing stresses as well as pore fluid pressures. In the absence of actual in-situ stress measurements, e.g. derived from boreholes, as is mostly the case in previously underexplored ;frontier areas;, such predictions are often difficult. In this study, the potential of reactivating pre-existing fractures in a likely exploration region of the southern Karoo of South Africa is investigated. The orientations of the present-day in-situ stresses were assessed from surrounding earthquake focal mechanisms, implying c. NW-SE oriented maximum horizontal stress and a stress regime changing between strike-slip and normal faulting. A comparison with paleo-stress axes derived from inverted fault-slip data suggests that the stress field very likely did not experience any significant reorientation since Cretaceous times. Maximum possible in-situ stress magnitudes are estimated by assuming that these are limited by frictional strength on pre-existing planes and subsequently, slip and dilation tendency calculations were performed, assuming hydrostatic pore fluid pressures of c. 32 MPa at targeted reservoir depth. The results suggest that prevalent E-W and NW-SE oriented sub-vertical fractures are likely to be reactivated at wellhead pressures exceeding hydrostatic pore fluid pressures by as little as 2-5 MPa, while less prevalent sub-horizontal and moderately inclined fractures require higher wellhead pressures that are still technically feasible

The thermal history of the Karoo Moatize-Minjova Basin, Tete Province, Mozambique: An integrated vitrinite reflectance and apatite fission track thermochronology study

Science.gov (United States)

Fernandes, Paulo; Cogné, Nathan; Chew, David M.; Rodrigues, Bruno; Jorge, Raul C. G. S.; Marques, João; Jamal, Daud; Vasconcelos, Lopo

2015-12-01

The Moatize-Minjova Basin is a Karoo-aged rift basin located in the Tete Province of central Mozambique along the present-day Zambezi River valley. In this basin the Permian Moatize and Matinde formations consist of interbedded carbonaceous mudstones and sandstones with coal seams. The thermal history has been determined using rock samples from two coal exploration boreholes (ca. 500 m depth) to constrain the burial and exhumation history of the basin. Organic maturation levels were determined using vitrinite reflectance and spore fluorescence/colour. Ages and rates of tectonic uplift and denudation have been assessed by apatite fission track analysis. The thermal history was modelled by inverse modelling of the fission track and vitrinite reflectance data. The Moatize Formation attained a coal rank of bituminous coals with low to medium volatiles (1.3-1.7%Rr). Organic maturation levels increase in a linear fashion downhole in the two boreholes, indicating that burial was the main process controlling peak temperature maturation. Calculated palaeogeothermal gradients range from 59 °C/km to 40 °C/km. According to the models, peak burial temperatures were attained shortly (3-10 Ma) after deposition. Apatite fission track ages [146 to 84 Ma (Cretaceous)] are younger than the stratigraphic age. Thermal modelling indicates two episodes of cooling and exhumation: a first period of rapid cooling between 240 and 230 Ma (Middle - Upper Triassic boundary) implying 2500-3000 m of denudation; and a second period, also of rapid cooling, from 6 Ma (late Miocene) onwards implying 1000-1500 m of denudation. The first episode is related to the main compressional deformation event within the Cape Fold Belt in South Africa, which transferred stress northwards on pre-existing transtensional fault systems within the Karoo rift basins, causing tectonic inversion and uplift. During the Mesozoic and most of the Cenozoic the basin is characterized by very slow cooling. The second period

Female self-employment among the Kleine Gemeinde in the Mennonite Settlement of Blue Creek, Northern Belize

NARCIS (Netherlands)

Roessingh, C.H.; Nuijten, M.

2012-01-01

This study explores the underexposed possibilities of starting and running a business by Mennonite women in the Kleine Gemeinde community of Blue Creek, Belize. The paper is the result of ethnographic fieldwork research combined with a literature study. We address the changing role of Kleine

The origins of disquieting discoveries by Melanie Klein: the possible significance of the case of 'Erna'.

Science.gov (United States)

Frank, C; Weiss, H

1996-12-01

Using the example of the analysis of 6-year-old Erna, which extended over more than two years and was the longest treatment conducted by Melanie Klein in her Berlin years, the authors demonstrate the importance of her early child analyses for the development of some of her concepts and hence for a decisive advance in psychoanalysis itself. For this purpose they adduce unpublished original documents found among Klein's papers in London, which include autobiographical material, the text of her Würzburg lecture on her obsessional-neurotic little patient, handwritten session notes, and drawings by Erna herself. Although in the author's view Klein attempted to accommodate her findings within Freud's theoretical framework, her clinical experience of the psychic reality of the relational world of early oedipality eventually called for the introduction of new concepts. The combined parent figure, primary sadism, the paranoid-schizoid position, splitting, the relevance of the death drive to the superego, and later formulations on reparation, envy and gratitude are all shown to be foreshadowed in Klein's account of the treatment of Erna. After some retrospective considerations of Erna's analysis and a fleeting glimpse of Erna as an adult, the authors conclude by emphasising the significance of Klein's emigration to England for the subsequent flowering of her work.

The general Klein-Gordon-Schroedinger system: modulational instability and exact solutions

International Nuclear Information System (INIS)

Tang Xiaoyan; Ding Wei

2008-01-01

The general Klein-Gordon-Schroedinger (gKGS) system is studied where the cubic auto-interactions are introduced in both the nonlinear Schroedinger and the nonlinear Klein-Gordon fields. We first investigate the modulational instability (MI) of the system, and thus derive the general dispersion relation between the frequency and wavenumber of the modulating perturbations, which demonstrates many possibilities for the MI regions. Using the travelling wave reduction, the gKGS system is greatly simplified. Via a simple function expansion method, we obtain some exact travelling wave solutions. Under some special parameter values, some representative wave structures are graphically displayed including the kink, anti-kink, bright, dark, grey and periodic solitons

Analytical solutions for Dirac and Klein-Gordon equations using Backlund transformations

Energy Technology Data Exchange (ETDEWEB)

Zabadal, Jorge R.; Borges, Volnei, E-mail: jorge.zabadal@ufrgs.br, E-mail: borges@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia Mecanica; Ribeiro, Vinicius G., E-mail: vinicius_ribeiro@uniritter.edu.br [Centro Universitario Ritter dos Reis (UNIRITTER), Porto Alegre, RS (Brazil); Santos, Marcio, E-mail: marciophd@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Centro de Estudos Interdisciplinares

2015-07-01

This work presents a new analytical method for solving Klein-Gordon type equations via Backlund transformations. The method consists in mapping the Klein-Gordon model into a first order system of partial differential equations, which contains a generalized velocity field instead of the Dirac matrices. This system is a tensor model for quantum field theory whose space solution is wider than the Dirac model in the original form. Thus, after finding analytical expressions for the wave functions, the Maxwell field can be readily obtained from the Dirac equations, furnishing a self-consistent field solution for the Maxwell-Dirac system. Analytical and numerical results are reported. (author)

Soliton supermultiplets and Kaluza-Klein theory

International Nuclear Information System (INIS)

Gibbons, G.W.; Perry, M.J.

1984-01-01

We show that the monopoles of five-dimensional Kaluza-Klein theory, considered as solutions of the N=8 supergravity theory in five dimensions, fit into the same supermultiplets as the original fields in that theory. We show that there is an electric-magnetic duality between these magnetic monopoles and the electrically charged antigravitating objects anticipated by Scherk. We formulate a Bogomolny inequality for N=8 supergravity, and we speculate on the wider significance of these monopoles. (orig.)

How best to quantify soil seed banks in arid rangelands of the Nama Karoo?

Science.gov (United States)

Dreber, Niels

2011-02-01

Sampling design and three sample treatments prior the application of the seedling emergence method were tested in order to find the best method for seed bank quantification in arid Nama Karoo rangelands. I analyzed species composition and seed densities by contrasting undercanopy and open-matrix samples from two soil depths and by comparing the effects of cold-, heat-, and no stratification on germination rates of species in a greenhouse setting. The soil seed bank showed minimal similarity to the standing vegetation, with only 20 plant species germinated. Spatial distribution of seeds was highly heterogeneous. Nearly 90% of germinated seeds were located in 0- to 4-cm compared to >4- to 8-cm soil depth. Undercanopy seed banks contained significantly more species and seeds than open-matrix seed banks. Neither the number nor the diversity of seeds germinated differed significantly among the three treatments. Cold stratification tended to detect more species and seeds only at >4- to 8-cm soil depth. The results highlight the importance of spatial heterogeneity in the accurate evaluation of soil seed banks in the arid Nama Karoo and the importance of considering seasonal variability in the availability of readily germinable seeds. Data also suggest that sample pretreatment in germination trials may give little return for cost and effort, which emphasizes that it is more important to choose the sampling design most likely to give a representative number of seed bank species. Further studies are needed to analyze seed bank dynamics and species-specific germination requirements to promote recruitment of plant taxa underrepresented in the seed bank.

Guiding conservation efforts in the Hantam–Tanqua–Roggeveld (South Africa using diversity parameters

Directory of Open Access Journals (Sweden)

Helga van der Merwe

2011-09-01

Full Text Available The Hantam–Tanqua–Roggeveld subregion falls within the Succulent Karoo and Fynbos Biomes, which are both recognised as global biodiversity hotspots that should be conserved. The objective of this study was to gather baseline biodiversity information that can be used to guide conservation efforts. A total of 40 Whittaker plots were surveyed in the subregion and the various diversity parameters calculated from the data were compared across the subregion and to available data for the Succulent Karoo and Fynbos Biomes. Species richness per 1000 m2 ranged from nine to 100 species across the subregion. Species richness for all plot sizes < 1000 m2 was significantly lower for the Tanqua Karoo than for both the Winter Rainfall Karoo and Mountain Renosterveld. The latter two areas did not differ significantly from each other with regard to species richness. Species richness was significantly higher only at the 1000 m2 scale in the Mountain Renosterveld compared to the Winter Rainfall Karoo. Evenness and Shannon and Simpson indices did not differ significantly between the Mountain Renosterveld and Winter Rainfall Karoo; however, these values were significantly higher than for the Tanqua Karoo. A principal coordinate analysis of species richness data at seven plot sizes produced three distinct clusters. One cluster represented the Tanqua Karoo, with low species richness, evenness, and Shannon and Simpson indices. Another cluster represented mostly Mountain Renosterveld vegetation, which was characterised by a high species richness, evenness, and Shannon and Simpson indices. The third cluster was formed by the remaining Mountain Renosterveld plots as well as the Winter Rainfall Karoo plots. The high species richness values found in the various vegetation units can add valuable information to the conservation planning arena by providing information on biodiversity parameters and their spatial distribution. This information can assist with conservation

Stratigraphic Stacking of Deepmarine Channel Levee Turbidites: Scales of Cyclicity and their Origin. Examples from the Laingsburg Fm. (Karoo, South Africa) and the Rosario Fm. (Baja, Mexico)

Science.gov (United States)

Kane, I. A.; Hodgson, D.

2009-12-01

Thinning upwards of the turbidite beds that form deepmarine channel levees is a common motif reported from modern and recent levees on the seafloor, from subsurface examples, and from outcropping ancient examples. Because levees are thought to be built by deposition from turbidity currents superelevated over their channel form, the volume and style of overbank deposition are controlled primarily by the relationship between levee height (i.e., thalweg to crest) and flow thickness, determining the amount of overspill. Thus stratigraphic variability of turbidite thickness is explained by some change in either or both of those factors, which may arise autocyclicly or allocyclicly. Variation in the ratio of intra-channel and extra-channel deposition can be an autocyclic stratigraphic response, e.g., in bypass dominated systems, thalweg aggradation may be retarded with respect to levee aggradation, hence as levee relief increases, flows become more confined and, given a relatively narrow range of flow sizes, the volume of overbank flow and deposit thickness decrease with stratigraphic height. However, the same stratigraphic response of the levee may occur due to allocyclic flow magnitude variation, i.e., through decreasing flow magnitude. In both the autocyclic and allocyclic case the stratigraphic response of the levee may be one of thinning upwards, even if the overall system response may be one of progradation (autocyclic bypassing case) or retrogradation (allocyclic decreasing flow magnitude case), with entirely different connotations for sequence stratigraphic interpretation. Here we report examples of different scales of bed thickness cyclicity (both thickening and thinning upward cycles superimposed by smaller scale cycles) within levees of the Rosario Formation, Baja California, Mexico, and from the Laingsburg Formation, Karoo, South Africa, and, together with published examples, discuss criteria for the recognition, and drivers of, autocyclic and allocyclic bed

Classification of palaeoriver types in the Karoo and their significance with regard to uranium mineralisation

International Nuclear Information System (INIS)

Le Roux, J.P.

1979-06-01

A new classification scheme whereby straight, low- and high-sinuosity rivers are differentiated, is proposed. The system is based on angular ranges of a river channel of 0-90 degrees Celsius, 90-180 degrees Celsius and 180-270 degrees Celsius, which correspond to sinuosity values of 1,11; 1,57 and 3,33 respectively. Preliminary findings on palaeoriver types and associated uranium mineralisation in the Karoo are discussed. The grade and dimensions of uraniferous lenses appear to be directly related to the type of river which deposited the sandstones hosting them [af

Shale Gas Development in the Central Karoo: A Scientific Assessment of the Opportunities and Risks

CSIR Research Space (South Africa)

Scholes, B

2016-11-01

Full Text Available Processes, Ecosystems and Species Ch 8 Impacts on Agriculture Ch 9 Impact on Tourism in the Karoo Ch 10 Impacts on the Economy Ch 11 Impacts on Social Fabric of 34 Municipalities Ch 12 Impact on Human Health Ch 13 Impact on Sense of Place Values Ch 14... process, is an approach for 7 considering all aspects of an issue in a common way, and in a spatial context. Risk is determined by 8 estimating the likelihood of events or trends occurring, in relation to their consequences (Figure 5). 9 10 11...

On the Kaluza/Klein miracle

International Nuclear Information System (INIS)

Wallner, R.P.; Urbantke, H.K.

1982-01-01

Using suitable adaptions of the calculus of exterior forms, we point out that the derivation of the Einstein/Yang-Mills Lagrangian with a (formal) cosmological term from the (Riemannian) scalar curvature density of a G-bundle space can be performed almost by inspection. This method also provides a simple explanation of this so-called 'Kaluza/Klein miracle'. The equivalence of the corresponding bundle field equations with the Einstein/Yang-Mills equations over the base is shown (i.e. there is no need for an 'integration over the group degrees of freedom'). The inclusion of matter fields is discussed briefly. (Author)

Seasonal and daily activity patterns of leopard tortoises ...

African Journals Online (AJOL)

Seasonal and daily activity patterns of leopard tortoises ( Stigmochelys pardalis Bell, 1828) on farmland in the Nama-Karoo, South Africa. ... that activity is also initiated by the time since sunrise. Key words: Stigmochelys pardalis, leopard tortoise, activity patterns, activity behaviour, Nama-Karoo Biome, time of day, season.

Some developments from the work of Melanie Klein.

Science.gov (United States)

Spillius, E B

1983-01-01

This paper discusses four areas of work in which several followers of Melanie Klein in Britain have developed some of the discoveries and ideas she initiated. First, extension of her concept of projective identification is briefly described, with emphasis on Bion's and Rosenfeld's stress on its communicative as well as its pathological aspects. Second, the extension of Klein's ideas about the epistemophilic instinct, on symbolism, and about projective identification is described in the work of Segal, Bion, Money-Kyrle, and Bick on the development of the capacity to think. Third, certain developments in Kleinian technique are described, with emphasis on the use of the concept of projective identification in analysing transference, and on the analysis of acting out in the transference, a trend contributed to by many Kleinian analysts but perhaps most closely associated with Betty Joseph. Finally, continued refinements in the analysis of the death instinct are briefly described, together with discussion of the changes these refinements have led to in ideas about the organization and relations of parts of the self and internal objects.

Engineering and science highlights of the KAT-7 radio telescope

NARCIS (Netherlands)

Foley, A. R.; Alberts, T.; Armstrong, R. P.; Barta, A.; Bauermeister, E. F.; Bester, H.; Blose, S.; Booth, R. S.; Botha, D. H.; Buchner, S. J.; Carignan, C.; Cheetham, T.; Cloete, K.; Coreejes, G.; Crida, R. C.; Cross, S. D.; Curtolo, F.; Dikgale, A.; de Villiers, M. S.; du Toit, L. J.; Esterhuyse, S. W. P.; Fanaroff, B.; Fender, R. P.; Fijalkowski, M.; Fourie, D.; Frank, B.; George, D.; Gibbs, P.; Goedhart, S.; Grobbelaar, J.; Gumede, S. C.; Herselman, P.; Hess, K. M.; Hoek, N.; Horrell, J.; Jonas, J. L.; Jordaan, J. D. B.; Julie, R.; Kapp, F.; Kotzé, P.; Kusel, T.; Langman, A.; Lehmensiek, R.; Liebenberg, D.; Liebenberg, I. J. V.; Loots, A.; Lord, R. T.; Lucero, D. M.; Ludick, J.; Macfarlane, P.; Madlavana, M.; Magnus, L.; Magozore, C.; Malan, J. A.; Manley, J. R.; Marais, L.; Marais, N.; Marais, S. J.; Maree, M.; Martens, A.; Mokone, O.; Moss, V.; Mthembu, S.; New, W.; Nicholson, G. D.; van Niekerk, P. C.; Oozeer, N.; Passmoor, S. S.; Peens-Hough, A.; Pińska, A. B.; Prozesky, P.; Rajan, S.; Ratcliffe, S.; Renil, R.; Richter, L. L.; Rosekrans, D.; Rust, A.; Schröder, A. C.; Schwardt, L. C.; Seranyane, S.; Serylak, M.; Shepherd, D. S.; Siebrits, R.; Sofeya, L.; Spann, R.; Springbok, R.; Swart, P. S.; Thondikulam, Venkatasubramani L.; Theron, I. P.; Tiplady, A.; Toruvanda, O.; Tshongweni, S.; van den Heever, L.; van der Merwe, C.; van Rooyen, R.; Wakhaba, S.; Walker, A. L.; Welz, M.; Williams, L.; Wolleben, M.; Woudt, P. A.; Young, N. J.; Zwart, J. T. L.

2016-01-01

The construction of the seven-dish Karoo Array Telescope (KAT-7) array in the Karoo region of the Northern Cape in South Africa was intended primarily as an engineering prototype for technologies and techniques applicable to the MeerKAT telescope. This paper looks at the main engineering and

An exact conformal symmetry Ansatz on Kaluza-Klein reduced TMG

Science.gov (United States)

Moutsopoulos, George; Ritter, Patricia

2011-11-01

Using a Kaluza-Klein dimensional reduction, and further imposing a conformal Killing symmetry on the reduced metric generated by the dilaton, we show an Ansatz that yields many of the known stationary axisymmetric solutions to TMG.

Vaarwel klein soldaat. Piet van Rooyen. Pretoria: Protea Boekhuis ...

African Journals Online (AJOL)

hedendaagse Japannese manga en anime word Miko dikwels uitgebeeld as gevaarlike vrouekrygers. Die strokiesprentagtige voor- stelling van 'n meisie in 'n gevegsposisie op die voorblad van Vaarwel, klein soldaat kan in verband gebring word met dié genres. Die roman herinner ook aan ander populêre genres.

Hydrodynamic representation of the Klein-Gordon-Einstein equations in the weak field limit

International Nuclear Information System (INIS)

Suárez, Abril; Chavanis, Pierre-Henri

2015-01-01

Using a generalization of the Madelung transformation, we derive the hydrodynamic representation of the Klein-Gordon-Einstein equations in the weak field limit. We consider a complex self-interacting scalar field with an arbitrary potential of the form V(|ϕ| 2 ). We compare the results with simplified models in which the gravitational potential is introduced by hand in the Klein-Gordon equation, and assumed to satisfy a (generalized) Poisson equation. Nonrelativistic hydrodynamic equations based on the Schrodinger-Poisson equations or on the Gross-Pitaevskii-Poisson equations are recovered in the limit c → +∞. (paper)

Karoo airborne geophysical survey: preliminary report on airborne radiometric data from block 12

International Nuclear Information System (INIS)

Day, R.W.; Wright, O.M.

1980-02-01

The analogue gamma-ray spectrometer records of block 12 of the Karoo airborne geophysical survey were studied and significant uranium anomalies were selected and graded. The anomalies were plotted on 1:50 000 scale maps and the co-ordinates of the anomalies were tabulated. The anomalies were transferred to 1:250 000 scale maps which are included in this report. The geological setting of the anomalies has been studied. Ground follow-up work has been recommended for anomalies which occur over mineralized pans and drainage channels, and the Lower Beaufort Stage. Other anomalies which occur over the Ecca Series, the Middle Beaufort Stage, the Upper Beaufort Stage and the Stormberg Series have also been recommended for ground investigation

A channel sediment budget for the 'Kleine Noordwaard' in the Biesbosch area, the Netherlands

Science.gov (United States)

van der Deijl, Eveline C.; van der Perk, Marcel; Zonneveld, Wouter; Verschelling, Eelco; Middelkoop, Hans

2015-04-01

Many deltas in the world are subject to drowning and loss of land due to accelerated soil subsidence, sea level rise, and sediment starvation. Effective delta restoration requires a thorough understanding of the rates and mechanisms of delta aggradation and their controls. This study aims to quantify the rates and patterns of aggradation in the Kleine Noordwaard, a former polder area in the Biesbosch area in the south-west of the Netherlands, in which water and sediment have been reintroduced since 2009. A sediment budget was established using existing bathymetric data collected using a multibeam echosounder and LiDAR digital elevation models collected since the opening of the polder, supplemented with field observations of the location and height of cut banks carried out between July and December 2014. Consecutive measurements of channel bathymetry showed a positive sediment budget in the channels between March 2009 and March 2013. During this period 59533 m3 of sediment was retained in the channels in the Kleine Noordwaard, which corresponds to an average sedimentation rate of 16.8 mm/year in the channels and 3.4 mm/year over the entire area. Sedimentation and aggradation primarily took place in the channels in the central part of the former polder area, whereas the channels near the entrance and outlet of the area underwent considerable erosion. It is therefore likely that a part of the sediment deposited in the central part of the system was supplied internally by upstream erosion of the channels. The results from the field observations suggest that cut-bank retreat also significantly contributes to internal sediment redistribution.

Etienne Klein Les sciences à la conquête du temps

CERN Multimedia

Franco, Fabien

2006-01-01

Etienne Klein grouped some of his works to the subject of time. On the occasion of his participation to thr 16e Sciences Festival in Chamonix, he gives a part of its thoughts about this matter (3 pages)

Towards Kaluza-Klein Dark Matter on nilmanifolds

Energy Technology Data Exchange (ETDEWEB)

Andriot, David [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, 14476 Potsdam-Golm (Germany); Institut für Mathematik, Humboldt-Universität zu Berlin,IRIS-Adlershof, Zum Großen Windkanal 6, 12489 Berlin (Germany); Cacciapaglia, Giacomo [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPNL,F-69622, Villeurbanne (France); Deandrea, Aldo [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPNL,F-69622, Villeurbanne (France); Institut Universitaire de France,103 boulevard Saint-Michel, 75005 Paris (France); Deutschmann, Nicolas [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPNL,F-69622, Villeurbanne (France); Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Tsimpis, Dimitrios [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPNL,F-69622, Villeurbanne (France)

2016-06-28

We present a first study of the field spectrum on a class of negatively-curved compact spaces: nilmanifolds or twisted tori. This is a case where analytical results can be obtained, allowing to check numerical methods. We focus on the Kaluza-Klein expansion of a scalar field. The results are then applied to a toy model where a natural Dark Matter candidate arises as a stable massive state of the bulk scalar.

The Kaluza-Klein idea: Status and prospects

International Nuclear Information System (INIS)

Mecklenburg, W.

1983-01-01

The present status of the Kaluza-Klein idea is reviewed, including a discussion of the fermionic sector. Formalism and geometrical methods necessary for the formulation of high-dimensional field theories are described in some detail. The mechanism of spontaneous compactification is explained and a description of presently available models is given. A chapter on coset space reduction of high dimensional Yang-Mills theories is included. The review concludes with an outlook on supersymmetric models. (author)

Perturbed Coulomb Potentials in the Klein-Gordon Equation: Quasi-Exact Solution

Science.gov (United States)

Baradaran, M.; Panahi, H.

2018-05-01

Using the Lie algebraic approach, we present the quasi-exact solutions of the relativistic Klein-Gordon equation for perturbed Coulomb potentials namely the Cornell potential, the Kratzer potential and the Killingbeck potential. We calculate the general exact expressions for the energies, corresponding wave functions and the allowed values of the parameters of the potential within the representation space of sl(2) Lie algebra. In addition, we show that the considered equations can be transformed into the Heun's differential equations and then we reproduce the results using the associated special functions. Also, we study the special case of the Coulomb potential and show that in the non-relativistic limit, the solution of the Klein-Gordon equation converges to that of Schrödinger equation.

Exploring Klein Bottles through Pottery: A STEAM Investigation

Science.gov (United States)

Smith, Christopher E.; Paré, Jana N.

2016-01-01

While one author was reading "The Simpsons and Their Mathematical Secrets by Simon Singh" (2013) in preparation for a presentation, the second author asked what in the book would be interesting to discuss. The topic of Klein bottles was on the first author's mind at that moment, so he tried to describe and explain the form to her--a real…

Rates of wood and dung disintegration in arid South African ...

African Journals Online (AJOL)

Dead shrubs lying on the soil surface in an arid shrubland in the southern Karoo have half-lives of 9 to 18 years depending on wood density which varies among species. Dung pellets of sheep and springbok can remain intact on the soil surface in Karoo shrubland and desert grassland for five years or more. Highlights the ...

Patronage in the dispute over child analysis between Melanie Klein and Anna Freud--1927-1932.

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Aguayo, J

2000-08-01

The author investigates the role of patrons and advocates for Melanie Klein's clinical ideas at the British Psycho-Analytical Society against the backdrop of her theoretical and technical differences with Anna Freud from 1927 to 1932. He also outlines the development of Klein and Anna Freud's theories and techniques within the nascent discipline of child psychoanalysis. The London and Viennese patrons/advocates contributed to polarising what initially were clinical differences about how to analyse pre-latency and latency-age children and which technical processes might best facilitate successful treatment. While the author speculates that a diversity of motivations and agendas may have driven the London group's support for Klein--personal and politicised enthusiasm (Jones), genuine conviction (Riviere) and attempts at theoretical rapprochement between the London and Vienna schools (Glover)--he also argues that Freud's diagnosis with cancer in 1923 and suspicion of patricidal son-successors necessitated the choice of a female successor with unquestioning loyalty to his doctrines. From 1932, when Klein's clinical authority was established, her first group of English supporters began to splinter, as she went on to become a training analyst, mentor and patron in her own right to a succeeding generation of adherents who defended her views during the Controversial Discussions.

THE STUDY AND TREATMENT OF MOTHERS AND INFANTS, THEN AND NOW: MELANIE KLEIN'S "NOTES ON BABY" IN A CONTEMPORARY PSYCHOANALYTIC CONTEXT.

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Aguayo, Joseph; Salomonsson, Björn

2017-04-01

This paper draws on Melanie Klein's (unpublished) observational notes of her infant grandson, written primarily in 1938 and 1939. Apart from moving glimpses into a young family's life, the notes contain astute observations of an infant's behavior and emotions. Compared with Klein's published writings, the style is less theoretical and polemical. Later, in his latency years, Klein's grandson was in analysis with Marion Milner, who in 1952 published a paper drawing on the treatment. The present paper focuses on (1) how observations and treatment of the same child and his family by clinicians in close relationships with each other (Klein, Milner, and Winnicott) fertilized reciprocal influence but also brought into question the validity of Klein's observations, and (2) the relative merits and contributions of various modalities in understanding the infant's psyche, including experimental research, direct observation, parent-infant psychotherapy, and reconstructions from older patients-as occurs, for example, in psychoanalysis. © 2017 The Psychoanalytic Quarterly, Inc.

Author Details

African Journals Online (AJOL)

Saayman, N. Vol 26, No 3 (2009) - Articles The impact of indigenous ungulate herbivory over five years (2004–2008) on the vegetation of the Little Karoo, South Africa Abstract · Vol 26, No 3 (2009) - Articles Can brush-cutting of Pteronia paniculata improve the composition and productivity of veld in the Succulent Karoo, ...

Klein paradox and vacuum polarization

International Nuclear Information System (INIS)

Damour, T.

1977-01-01

This contribution reviews some of the methods which can be used when studying quantum fields in a given stationary classical external field. The attention is mainly directed towards cases where real pair creation can occur in such a stationary background. The paradigm of this situation is the Klein paradox. This paradox is best approached by the introduction of some energy diagrams whose direct extension to black holes physics has proven to be very useful. Finally processes of real pair creation around a Kerr-Newman (charged and rotating) black hole and their feedback on the geometry are briefly discussed. It is also shown how the Hawking process can be recovered in this approach. (Auth.)

Kaluza-Klein straw as a string-guide

International Nuclear Information System (INIS)

Davidson, A.; Zamir, R.

1989-01-01

Cosmic strings may acquire topological stability by wrapping around the fifth dimension, in which case the Kaluza-Klein ''straw'' plays the role of a string-guide. The only fundamental velocity of the string is then the speed of light, decomposed into the center-of-mass velocity in four dimensions and the group velocity around the fifth dimension. The energy/momentum singularity, on the other hand, is associated with a critical phase velocity. A linear electromagnetic mass formula is derived. (orig.)

South African uranium resources - 1997 assessment methodology and results

International Nuclear Information System (INIS)

Ainslie, L.C.

2001-01-01

The first commercial uranium production in South Africa started in 1953 to meet the demand for British/US nuclear weapons. This early production reached its peak in 1959 and began to decline with the reduced demand. The world oil crisis in the 1970s sparked a second resurgence of increased uranium production that peaked in 1980 to over 6,000 tonnes. Poor market condition allied with increasing political isolation resulted in uranium production declining to less than a third of the levels achieved in the early 1980s. South Africa is well endowed with uranium resource. Its uranium resources in the RAR and EAR-I categories, extractable at costs of less than $80/kg U, as of 1 January 1997, are estimated to 284 400 tonnes U. Nearly two thirds of these resources are associated with the gold deposits in the Witwatersrand conglomerates. Most of the remaining resources occur in the Karoo sandstone and coal deposits. (author)

Near-Integrability of Low-Dimensional Periodic Klein-Gordon Lattices

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Ognyan Christov

2018-01-01

Full Text Available The low-dimensional periodic Klein-Gordon lattices are studied for integrability. We prove that the periodic lattice with two particles and certain nonlinear potential is nonintegrable. However, in the cases of up to six particles, we prove that their Birkhoff-Gustavson normal forms are integrable, which allows us to apply KAM theory in most cases.

Embracing "All But My Life" by Gerda Weissmann Klein.

Science.gov (United States)

Foster, Harold M.

1997-01-01

Discusses Gerda Weissmann Klein's book, "All But My Life," which chronicles the author's journey from a normal young (Jewish) woman to a slave in Nazi labor camps for six years. Argues that the book is well written, has characters of depth and complexity, affirms life through the ordeal of the Holocaust, and is a popular book with…

Killing spinors for the bosonic string and Kaluza-Klein theory with scalar potentials

International Nuclear Information System (INIS)

Liu, Haishan; Lue, H.; Wang, Zhao-Long

2012-01-01

The paper consists mainly of two parts. In the first part, we obtain well-defined Killing spinor equations for the low-energy effective action of the bosonic string with the conformal anomaly term. We show that the conformal anomaly term is the only scalar potential that one can add into the action that is consistent with the Killing spinor equations. In the second part, we demonstrate that Kaluza-Klein theory can be gauged so that the Killing spinors are charged under the Kaluza-Klein vector. This gauging process generates a scalar potential with a maximum that gives rise to an AdS spacetime. We also construct solutions of these theories. (orig.)

On Hamiltonians with position-dependent mass from Kaluza–Klein compactifications

Energy Technology Data Exchange (ETDEWEB)

Ballesteros, Ángel, E-mail: angelb@ubu.es; Gutiérrez-Sagredo, Iván, E-mail: igsagredo@ubu.es; Naranjo, Pedro, E-mail: pnaranjo@ubu.es

2017-02-19

In a recent paper (Morris (2015) ), an inhomogeneous compactification of the extra dimension of a five-dimensional Kaluza–Klein metric has been shown to generate a position-dependent mass (PDM) in the corresponding four-dimensional system. As an application of this dimensional reduction mechanism, a specific static dilatonic scalar field has been connected with a PDM Lagrangian describing a well-known nonlinear PDM oscillator. Here we present more instances of this construction that lead to PDM systems with radial symmetry, and the properties of their corresponding inhomogeneous extra dimensions are compared with the ones in the nonlinear oscillator model. Moreover, it is also shown how the compactification introduced in this type of models can alternatively be interpreted as a novel mechanism for the dynamical generation of curvature. - Highlights: • New position-dependent mass systems arising from inhomogeneous Kaluza–Klein compactifications are presented. • Connections with known integrable position-dependent mass systems are established. • A novel mechanism for the dynamical generation of curvature is proposed.

Possible trace fossils of putative termite origin in the Lower Jurassic (Karoo Supergroup of South Africa and Lesotho

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O. Catuneanu

2010-01-01

Full Text Available Complex structures in the sandstones of the Lower Jurassic aeolian Clarens Formation (Karoo Supergroup are found at numerous localities throughout southern Africa, and can be assigned to five distinct architectural groups: (1 up to 3.3-m high, free-standing, slab-shaped forms of bioturbated sandstones with elliptical bases, orientated buttresses and an interconnecting large burrow system; (2 up to 1.2-m high, free-standing, irregular forms of bioturbated sandstones with 2-cm to 4-cm thick, massive walls, empty chambers and vertical shafts; (3 about 0.15-m to 0.25-m high, mainly bulbous, multiple forms with thin walls (larger than 2 cm, hollow chambers with internal pillars and bridges; (4 about 0.15-m to 0.2-m (maximum 1-m high, free-standing forms of aggregated solitary spheres associated with massive horizontal, orientated capsules or tubes, and meniscate tubes; and (5 about 5 cmin diameter, ovoid forms with weak internal shelving in a close-fitting cavity. Based on size, wall thickness, orientation and the presence of internal chambers, these complex structures are tentatively interpreted as ichnofossils of an Early Jurassic social organism; the different architectures are reflective of the different behaviours of more than one species, the history of structural change in architectural forms (ontogenetic series or an architectural adaptation to local palaeoclimatic variability. While exact modern equivalents are unknown, some of these ichnofossils are comparable to nests (or parts of nests constructed by extant termites, and thus these Jurassic structures are very tentatively interpreted here as having been made by a soil-dwelling social organism, probably of termite origin. This southern African discovery, along with reported Triassic and Jurassic termite ichnofossils from North America, supports previous hypotheses that sociality in insects, particularity in termites, likely evolved prior to the Pangea breakup in the Early Mesozoic.

The life and work of Melanie Klein in the British Psycho-Analytical Society.

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King, P H

1983-01-01

This paper describes certain aspects of the life and work of Melanie Klein in the British Psycho-Analytical Society. It attempts to highlight the reciprocity of the relationship between Melanie Klein and other members of that Society by showing how the climate of psychoanalytical opinion that was prevalent among members of that Society during the first decade of her stay in London, and which encouraged discussion of clinical work and interest in psychoanalytical discovery, provided a congenial setting for her to become firmly established as an active member of the British Society and to continue her contributions to psychoanalytic theory and clinical expertise. The paper also traces the development of Melanie Klein's main theoretical contributions, together with relevant criticisms of them as they emerged, against the background of the history of the British Psycho-Analytical Society. It describes the controversies that arose as to whether or not her ideas could properly be viewed within the framework of psychoanalytic theory, as formulated by Freud, and the attempted resolution of these controversies, together with some comments on the repercussions of these theoretical disagreements on relationships within the Society. An extensive list of references is included to facilitate a more detailed study of the subject.

On 'the fear of death' as the primary anxiety: how and why Klein differs from Freud.

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Blass, Rachel B

2014-08-01

It is well known that Melanie Klein held the view that 'fear of death' is the primary source of anxiety and that her position is explicitly opposed to that of Sigmund Freud, who maintained that that fear cannot in any way or form be a source of anxiety. In a previous article on Freud's Inhibitions, Symptoms and Anxiety (Blass, 2013), the author argued that, counter to what is commonly portrayed in the literature, Freud's considerations for rejecting the fear of death as a source of anxiety were based on relational and experiential factors that are usually associated with Kleinian psychoanalysis. In light of this affinity of Freud with Klein a question arises as to the actual source of their differences in this context. The present paper offers an answer to this question. The author first presents some of her earlier findings on what led Freud to reject the fear of death as a source of anxiety and then turns to investigate Klein's considerations for accepting it. This takes us beyond her explicit statements on this matter and sheds new light on the relationship of her views regarding death and anxiety and those of Freud. In turn this deepens the understanding of the relationship of Freud and Klein's conceptualizations of the psyche and its internal object relations, pointing to both surprising common ground and foundational differences. Copyright © 2014 Institute of Psychoanalysis.

The klein paradox as a many particle problem

International Nuclear Information System (INIS)

Bongaarts, P.J.M.; Ruijsenaars, S.N.M.

1976-01-01

A mathematically rigorous analysis of the Klein paradox is given in the many-particle formulation of the Dirac theory. This paradox was meant as an example demonstrating the negative energy problems of the single particle Dirac equation. However, it is shown that this problem does not disappear in the second quantized version of the Dirac theory. It corresponds with a situation which cannot be described properly within the framework of a field theory with an external potential

Constraints on cosmic superstrings from Kaluza-Klein emission.

Science.gov (United States)

Dufaux, Jean-François

2012-07-06

Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.

Hyperbolic manifolds as vacuum solutions in Kaluza-Klein theories

International Nuclear Information System (INIS)

Aref'eva, I.Ya.; Volovich, I.V.

1985-08-01

The relevance of compact hyperbolic manifolds in the context of Kaluza-Klein theories is discussed. Examples of spontaneous compactification on hyperbolic manifolds including d dimensional (d>=8) Einstein-Yang-Mills gravity and 11-dimensional supergravity are considered. Some mathematical facts about hyperbolic manifolds essential for the physical content of the theory are briefly summarized. Non-linear σ-models based on hyperbolic manifolds are discussed. (author)

Introduction to Kaluza-Klein-theories

International Nuclear Information System (INIS)

Blau, M.; Thirring, W.; Landi, G.

1986-01-01

In 1919 Th. Kaluza made a remarkable observation. If one considers Einstein's theory in 5 dimensions and calculates with the ansatz g = gsup(μν) dxsub(μ) dxsub(ν) + (dx 5 + Asup(μ)dxsub(μ)) 2 , μ = 1,...4 (1.1), and gsup(μν)sub(,5) = Asup(μ)sub(,5) = 0 the curvature scalar Rsup((5)) in 5 dimensions one finds Rsup((5)) = Rsup((4)) - 1/4 x (Asub(μ,ν) - Asub(ν,μ)) x (Asup(μ,ν) - Asup(ν,μ)). Thus this Lagrangian reproduces exactly the coupled Einstein-Maxwell equations. A realistic interpretation of the ansatz (1.1) is nowadays thinkable. Restricting to pure gravity the physics of 4+D-dimensional Einstein spaces with a structure given by (1.1) is considered. Finally a Kaluza-Klein cosmology is outlined. (G.Q.)

Between practice and theory: Melanie Klein, Anna Freud and the development of child analysis.

Science.gov (United States)

Donaldson, G

1996-04-01

An examination of the early history of child analysis in the writings of Melanie Klein and Anna Freud reveals how two different and opposing approaches to child analysis arose at the same time. The two methods of child analysis are rooted in a differential emphasis on psychoanalytic theory and practice. The Kleinian method derives from the application of technique while the Anna Freudian method is driven by theory. Furthermore, by holding to the Freudian theory of child development Anna Freud was forced to limit the scope of child analysis, while Klein's application of Freudian practice has led to new discoveries about the development of the infant psyche.

Theories on anxiety in Freud and Melanie Klein. Their metapsychological status.

Science.gov (United States)

De Bianchedi, E T; Scalozub De Boschan, L; De Cortiñas, L P; De Piccolo, E G

1988-01-01

This paper presents a comparative study of the theories on anxiety formulated by Freud and Melanie Klein, with particular emphasis on the questions of its origin, its meaning for the individual and its function in both theoretical systems. The purpose of this comparative analysis is to offer an instrument which helps frame the theoretical discussions in psychoanalysis in an epistemological context. The authors hold that for Freud anxiety is considered as one more amongst the various manifestations of mental life, which his general theories try to explain, whereas for Melanie Klein anxiety and its destinies occupies a central place in her theories on mental functioning. The differences in both theories, which the authors of this paper describe, especially as to origin, function and meaning of anxiety, respond partially to the different metapsychological points of view with which both authors focus mental life--points of view which they have themselves investigated in a previous paper.

Antigravity and classical solutions of five-dimensional Kaluza-Klein theory

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Pollard, D. (Imperial Coll. of Science and Technology, London (UK). Blackett Lab.)

1983-02-21

Classical solutions are exhibited of a graviton-graviphoton-graviscalar field theory which are antigravitating in the weak-field approximation. The theory itself is obtained by a Kaluza-Klein type reduction from five to four dimensions. The solutions are dyonic black holes with scalar charge. They share some similarities with the extreme Reissner-Nordstrom black holes of Einstein-Maxwell theory.

New phases of thermal SYM and LST from Kaluza-Klein black holes

DEFF Research Database (Denmark)

Harmark, Troels; Obers, Niels A.

2005-01-01

between phases of Kaluza-Klein black holes and the thermodynamic behavior of the non-gravitational theories dual to near-extremal branes on a circle. In particular, for the thermodynamics of strongly-coupled supersymmetric Yang-Mills theories on a circle we predict the existence of a new non-uniform phase......We review the recently found map that takes any static and neutral Kaluza-Klein black hole, i.e. any static and neutral black hole on Minkowski-space times a circle Md × S1, and maps it to a corresponding solution for a non- and near-extremal brane on a circle. This gives a precise connection...... and find new information about the localized phase. We also find evidence for the existence of a new stable phase of (2, 0) Little String Theory in the canonical ensemble for temperatures above its Hagedorn temperature....

On the present status of the Klein Paradox

International Nuclear Information System (INIS)

Wergeland, H.

1980-01-01

Klein's paradox is a solution of Dirac's equation which implies that electrons may penetrate an electrostatic potential barrier even when their kinetic energy is lower than the barrier. Since the barrier is infinitely broad this is not a case of tunneling. A number of treatments of the paradox, by Sauter, Hylleraas, Jenssen and others are discussed, and the Boundary Value Problem is treated at some length. Examples are presented with an infinitely broad barrier and with a barrier of finite breadth. (JIW)

Hochschild Homology and Cohomology of Klein Surfaces

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Frédéric Butin

2008-09-01

Full Text Available Within the framework of deformation quantization, a first step towards the study of star-products is the calculation of Hochschild cohomology. The aim of this article is precisely to determine the Hochschild homology and cohomology in two cases of algebraic varieties. On the one hand, we consider singular curves of the plane; here we recover, in a different way, a result proved by Fronsdal and make it more precise. On the other hand, we are interested in Klein surfaces. The use of a complex suggested by Kontsevich and the help of Groebner bases allow us to solve the problem.

Vortex configuration in topological insulators from (1+3) Kaluza-Klein compactification

International Nuclear Information System (INIS)

Ferreira, Cristine Nunes; Lima, Carlos Eduardo Campos; Helayel-Neto, Jose Abdalla; Paredes, Alfredo A.V.

2011-01-01

Full text: Quantum electrodynamics in (1+2)-D is a super-renormalizable gauge theory with some resemblance to four-dimensional theories whenever analyzed in the framework on an 1=N f -expansion. It is possible to show that, by using the fermionic sector of supersymmetric models that result from a (1+3)-D space-time upon compactification, there appears a U(2)-symmetry. We investigate the breakdown study of this symmetry by considering some specific sectors, such as the couplings and the vortex configurations that appear as particular solutions of the model. The construction and the study of models the QCD 3 -type can set up a new bridge of common interests between the condensed matter and high-energy physics communities. The point of view of the condensed matter also helps us to understand materials like graphene, whose description is associated to a massless Dirac equation or topological insulators. The latter, once coupled to vortex configurations, in the low-energy approximation, can generate a mass gap into the Dirac equation through the coupling with fermions. In this work, we consider a Kaluza-Klein compactification from a (1 + 3) supersymmetric model with the Maxwell-Chern-Simons term. The whole motivation behind this contribution is to consider the vortex configuration in (1+2)-D and its coupling to the fermionic sector of the model as a possible interpretation of the topological insulators. As the compactification mechanism adopted is the Kaluza-Klein reduction, we propose an interpretation of the Kaluza- Klein n-modes in connection with the vortices that may be formed in the surface of topological insulators. (author)

What happens to linear properties as we move from the Klein-Gordon equation to the sine-Gordon equation

International Nuclear Information System (INIS)

Kovalyov, Mikhail

2010-01-01

In this article the sets of solutions of the sine-Gordon equation and its linearization the Klein-Gordon equation are discussed and compared. It is shown that the set of solutions of the sine-Gordon equation possesses a richer structure which partly disappears during linearization. Just like the solutions of the Klein-Gordon equation satisfy the linear superposition principle, the solutions of the sine-Gordon equation satisfy a nonlinear superposition principle.

Special relativity of Kaluza-Klein

International Nuclear Information System (INIS)

Maia, M.D.

1984-01-01

Kaluza-Klein theory is formulated from the point of view of the Gauss geometry of embedded manifolds. According to this view, space-time is regarded as locally and isometrically embedded in the high dimensional space predicted by that theory. The high dimensional Minkowski space is considered as a particular solution of the high dimensional vacuum Einstein's equations and it is assumed to represent the ground state of the theory. In this particular case it is shown that the compactification of the space of internal variables follows from the second quadratic forms of the Gaussian geometry of space-time. The Gauss-Codazzi-Ricci integrability conditions are interpreted as the field equations for a low energy observer. The space-time reduced Einstein-Hilbert action is interpreted as an integral equation on the size of the internal space. 13 references

Infinite dimensional gauge structure of Kaluza-Klein theories II: D>5

International Nuclear Information System (INIS)

Aulakh, C.S.; Sahdev, D.

1985-12-01

We carry out the dimensional reduction of the pure gravity sector of Kaluza Klein theories without making truncations of any sort. This generalizes our previous result for the 5-dimensional case to 4+d(>1) dimensions. The effective 4-dimensional action has the structure of an infinite dimensional gauge theory

Antigravity and classical solutions of five-dimensional Kaluza-Klein theory

International Nuclear Information System (INIS)

Pollard, D.

1983-01-01

Classical solutions are exhibited of a graviton-graviphoton-graviscalar field theory which are antigravitating in the weak-field approximation. The theory itself is obtained by a Kaluza-Klein type reduction from five to four dimensions. The solutions are dyonic black holes with scalar charge. They share some similarities with the extreme Reissner-Nordstrom black holes of Einstein-Maxwell theory. (author)

Massless versus Kaluza-Klein gravitons at the LHC

International Nuclear Information System (INIS)

Calmet, Xavier; Aquino, Priscila de; Rizzo, Thomas G.

2010-01-01

We show that the LHC will be able to differentiate between a four-dimensional model with quantum gravity at ∼1 TeV where the (massless) graviton becomes strongly coupled to standard model particles at 1 TeV and brane world type models with a large extra-dimensional volume and massive Kaluza-Klein gravitons. We estimate that the 14 TeV LHC could put a limit of the order of ∼5 TeV on the four-dimensional Planck mass in a model independent way.

Nuclearity, split-property and duality for the Klein-Gordon field in curved spacetime

International Nuclear Information System (INIS)

Verch, R.

1993-05-01

Nuclearity, Split-Property and Duality are establihed for the nets of von Neumann algebras associated with the representations of distinguished states of the massive Klein-Gordon field propagating in particular classes of curved spacetimes. (orig.)

The Struggle of Integration: James Baldwin and Melanie Klein in the Context of Black Lives Matter

Directory of Open Access Journals (Sweden)

David W McIvor

2016-12-01

Full Text Available Recent killings of unarmed black citizens are a fresh reminder of the troubled state of racial integration in the United States. At the same time, the unfolding Black Lives Matter protest movements and the responses by federal agencies each testify to a not insignificant capacity for addressing social pathologies surrounding the color line. In order to respond to this ambivalent situation, this article suggests a pairing between the work of James Baldwin and that of the psychoanalyst Melanie Klein. I will argue that we cannot fully appreciate the depths of what Baldwin called the “savage paradox” of race without the insights provided by Klein and object relations psychoanalysis. Conversely, Baldwin helps us to sound out the political significance of object relations approaches, including the work of Klein and those influenced by her such as Hanna Segal and Wilfred Bion. In conversation with the work of Baldwin, object relations theory can help to identify particular social settings and institutions that might allow concrete efforts toward racial justice to take root.

The "new" democratic woman of modernity: Georgia O'Keeffe and Melanie Klein.

Science.gov (United States)

Gadt, J C

1994-06-01

O'Keeffe put into visual language the psychic splitting that had occurred between the sexes in the United States, attempting to integrate what had formerly been separated as feminine and masculine into the female psyche. In her most important contribution, she explored presence rather than absence and opened up possibilities for thinking about openings. The concept of the female opening in particular had heretofore been assigned a negative meaning, signifying more often than not a gaping wound rather than a space and place of possibilities. Klein's complex and evocative understanding of some of the earliest mental processes of life enabled researchers to delve into the meanings made of the presence of the mother and father and baby, in the context of the baby's body-mind. Klein's female or male baby desires to know from the beginning. She discovered splitting and projective identification, the development of anxiety and guilt under the aegis of these mental processes, the multiple meanings of aggression, and, significantly, she permitted the female baby's body to have its own language. The answers provided by O'Keeffe and Klein bequeathed new possibilities for women's self-invention and remain pivot points for female identity throughout the century, to be confronted again by the second wave of feminism beginning in the late 1960s, by "postfeminist" debates, and by a challenged psychoanalysis. A more careful probing of these issues may help us to better understand our past so as to have greater resources for a more comprehensive reading of our present.

Uniform decay for a local dissipative Klein-Gordon-Schrodinger type system

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Marilena N. Poulou

2012-10-01

Full Text Available In this article, we consider a nonlinear Klein-Gordon-Schrodinger type system in $mathbb{R}^n$, where the nonlinear term exists and the damping term is effective. We prove the existence and uniqueness of a global solution and its exponential decay. The result is achieved by using the multiplier technique.

Deep-water sponges (Porifera) from Bonaire and Klein Curacao, Southern Caribbean

NARCIS (Netherlands)

Soest, R.W.M.; Meesters, H.W.G.; Becking, L.E.

2014-01-01

Four submersible dives off the coast of Bonaire (Caribbean Netherlands) and Klein Curaçao (Curaçao) to depths of 99.5–242 m, covering lower mesophotic and upper dysphotic zones, yielded 52 sponge specimens belonging to 31 species. Among these we identified 13 species as new to science. These are

A Case of Kleine-Levin Syndrome: Diagnostic and Therapeutic Challenge

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Marino Marčić

2018-02-01

Full Text Available Kleine-Levin syndrome (KLS is a rare sleep disorder mainly affecting teenage boys in which the main features are intermittent hypersomnolence, behavioral and cognitive disturbances, hyperphagia, and in some cases hyper sexuality. Etiology is unknown, and there is no specific clinical or imaging test for this syndrome even though the illness has well-defined clinical features. Also, there is no effective treatment for KLS. KLS is self-limited, so the prognosis for these patients is not so bad. This study presents our case report and comprehensive workout that led to diagnosis which is primarily clinical. Our patient is a 20-year-old man referred to our clinic because of sleeping problems. At the age of 14, he presented with complaints of the excessive duration of sleep, increased appetite, excessive daytime sleepiness, loss of interest in social activities during attendance of high school and hallucinations. The excessive diagnostic procedure does not find pathological. Kleine-Levin syndrome (KLS is a rare sleep disorder of unknown etiology which diagnosis is clinical and diagnostic workup is mainly to exclude other similar conditions. There is no specific therapy, but the disease is self-limited and with good prognosis.

All but Her Life: Holocaust Survivor Gerda Klein Shares with Learners

Science.gov (United States)

Lincoln, Margaret

2007-01-01

During the 2006-2007 school year, students from Battle Creek, Michigan, high school joined numerous others from across the state in reading holocaust survivor Gerda Klein's memoir, "All But My Life." Published in 57 editions and still in print after 50 years, the book is the inspiring account of a remarkable individual who endured unspeakable…

Kaluza–Klein-type models of de Sitter and Poincaré gauge theories of gravity

International Nuclear Information System (INIS)

Lu Jiaan; Huang Chaoguang

2013-01-01

We construct Kaluza–Klein-type models with a de Sitter or Minkowski bundle in the de Sitter or Poincaré gauge theory of gravity, respectively. A manifestly gauge-invariant formalism has been given. The gravitational dynamics is constructed by the geometry of the de Sitter or Minkowski bundle and a global section which plays an important role in the gauge-invariant formalism. Unlike the old Kaluza–Klein-type models of gauge theory of gravity, a suitable cosmological term can be obtained in the Lagrangian of our models and the models in the spin-current-free and torsion-free limit will come back to general relativity with a corresponding cosmological term. We also generalize the results to the case with a variable cosmological term. (paper)

Neuroimaging of Narcolepsy and Kleine-Levin Syndrome.

Science.gov (United States)

Hong, Seung Bong

2017-09-01

Narcolepsy is a chronic neurologic disorder with the abnormal regulation of the sleep-wake cycle, resulting in excessive daytime sleepiness, disturbed nocturnal sleep, and manifestations related to rapid eye movement sleep, such as cataplexy, sleep paralysis, and hypnagogic hallucination. Over the past decade, numerous neuroimaging studies have been performed to characterize the pathophysiology and various clinical features of narcolepsy. This article reviews structural and functional brain imaging findings in narcolepsy and Kleine-Levin syndrome. Based on the current state of research, brain imaging is a useful tool to investigate and understand the neuroanatomic correlates and brain abnormalities of narcolepsy and other hypersomnia. Copyright © 2017 Elsevier Inc. All rights reserved.

Kaluza-Klein theories and the signature of space-time

International Nuclear Information System (INIS)

Aref'eva, I.Ya.; Volovich, I.V.

1985-06-01

Higher-dimensional Kaluza-Klein theories with extra compactified time-like variables are considered. Topological criteria are presented for a compact manifold which prevent the appearance of massless ghosts in an effective four-dimensional theory. Some models are given in which these criteria hold. Among them is the bosonic sector of the low-energy limit of the anomaly-free superstring theories. As a rule, the extra time-like variables lead to compactification with a compact hyperbolic manifold. (author)

An unusual occurrence of Kleine-Levin syndrome in a man with refractory immune thrombocytopenic purpura: a case report.

Science.gov (United States)

Amirifard, Hamed; Barzkar, Farzaneh; Fazeli, Seyed Amirhossein; Hashemi, Seyed Mehdi

2015-04-01

Kleine-Levin syndrome is an extremely rare neurological entity characterized by recurrent episodes of hypersomnia which are sometimes associated with compulsive hyperphagia and behavioral changes. Autoimmunity has recently been proposed as a factor contributing to its pathogenesis. Immune thrombocytopenic purpura is a relatively common autoimmune disease showing a lot of complexity and uncertainty regarding its treatment regimens and its refractory nature in some cases. A 32-year-old Persian White man visited his private hematologist complaining of recent episodes of epistaxis and appearance of petechial lesions 24 hours after receiving a meningococcal vaccine. He had a history of immune thrombocytopenic purpura 13 years before his presentation. Based on his history and laboratory findings, his condition was diagnosed as a relapse of immune thrombocytopenic purpura and was managed accordingly. He did not respond to first-line corticosteroid regimens and later developed neurological symptoms as recurrent episodes of hypersomnia and hyperphagia. After a complete clinical and paraclinical evaluation and ruling out other possible conditions, he was given a diagnosis of Kleine-Levin syndrome. He was followed up for his immune thrombocytopenic purpura and received different treatment regimens none of which were adequately successful except intravenous immunoglobulin that was only temporarily effective. He has had 4 documented self-limited episodes of Kleine-Levin syndrome since his initial presentation. Immune thrombocytopenic purpura may be associated with meningococcal vaccination in adulthood. Responses to treatment in immune thrombocytopenic purpura vary among patients. Our patient only had a transient acceptable response to intravenous immunoglobulin while all other options failed to improve his platelet count. Concurrence of immune thrombocytopenic purpura and Kleine-Levin syndrome supports the role of autoimmunity as the proposed pathophysiological mechanism of

Lacan Leitor de Melanie Klein: O Caso Dick em Questão

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Ariana Lucero

Full Text Available RESUMO O artigo apresenta a leitura que Jacques Lacan faz do caso Dick, de Melanie Klein. Para tanto, a discussão com o filósofo Jean Hyppolite é retomada com o objetivo de explicitarmos como os mecanismos de Ausstossung [expulsão], Verneinung [negação] e Bejahung [afirmação], descritos por Freud em 1925, podem contribuir para a compreensão da constituição psíquica sob uma perspectiva lacaniana. Em seguida, expomos o caso, tanto para apreendermos clinicamente o que foi exposto na teoria, quanto para evidenciarmos como Lacan se distancia da concepção de fantasia de M. Klein. O tema do diagnóstico, no entanto, aparece em ambos ligado a uma forma de organização subjetiva ainda em constituição na infância, o que traz elementos para refletirmos sobre essa questão na atualidade.

Kaluza-Klein cosmology from five-dimensional Lovelock-Cartan theory

Science.gov (United States)

Castillo-Felisola, Oscar; Corral, Cristóbal; del Pino, Simón; Ramírez, Francisca

2016-12-01

We study the Kaluza-Klein dimensional reduction of the Lovelock-Cartan theory in five-dimensional spacetime, with a compact dimension of S1 topology. We find cosmological solutions of the Friedmann-Robertson-Walker class in the reduced spacetime. The torsion and the fields arising from the dimensional reduction induce a nonvanishing energy-momentum tensor in four dimensions. We find solutions describing expanding, contracting, and bouncing universes. The model shows a dynamical compactification of the extra dimension in some regions of the parameter space.

The Klein paradox: a new treatment

International Nuclear Information System (INIS)

Truebenbacher, E

2015-01-01

The Dirac equation requires a treatment of the step potential that differs fundamentally from the traditional treatment, because the Dirac plane waves, besides momentum and spin, are characterized by a quantum number with the physical meaning of sign of charge. Since the Hermitean operator corresponding to this quantum number does not commute with the step potential, the time displacement parameter used in the ansatz of the stationary state does not have the physical meaning of energy. Therefore there are no paradoxal values of the ‘energy’. The new solution of the Dirac equation with a step potential is obtained. This solution, again, allows for phenomena of the Klein paradox type, but in addition it contains a positron amplitude localized at the threshold point of the step potential. (paper)

Suppressing Klein tunneling in graphene using a one-dimensional array of localized scatterers.

Science.gov (United States)

Walls, Jamie D; Hadad, Daniel

2015-02-13

Graphene's unique physical and chemical properties make it an attractive platform for use in micro- and nanoelectronic devices. However, electrostatically controlling the flow of electrons in graphene can be challenging as a result of Klein tunneling, where electrons normally incident to a one-dimensional potential barrier of height V are perfectly transmitted even as V → ∞. In this study, theoretical and numerical calculations predict that the transmission probability for an electron wave normally incident to a one-dimensional array of localized scatterers can be significantly less than unity when the electron wavelength is smaller than the spacing between scatterers. In effect, placing periodic openings throughout a potential barrier can, somewhat counterintuitively, decrease transmission in graphene. Our results suggest that electrostatic potentials with spatial variations on the order of the electron wavelength can suppress Klein tunneling and could find applications in developing graphene electronic devices.

Perron-Frobenius operators and the Klein-Gordon equation

OpenAIRE

Canto-Martin, Francisco; Hedenmalm, Haakan; Montes-Rodriguez, Alfonso

2012-01-01

For a smooth curve Γ and a set Λ in the plane R2, let AC(Γ; Λ) be the space of finite Borel measures in the plane supported on Γ, absolutely continuous with respect to the arc length and whose Fourier transform vanishes on Λ. Following [12], we say that (Γ, Λ) is a Heisenberg uniqueness pair if AC(Γ; Λ) = {0}. In the context of a hyperbola Γ, the study of Heisenberg uniqueness pairs is the same as looking for uniqueness sets Λ of a collection of solutions to the Klein-Gordon equation. In t...

Massless fermions and Kaluza--Klein theory with torsion

International Nuclear Information System (INIS)

Wu, Y.; Zee, A.

1984-01-01

A pure Kaluza--Klein theory contains no massless fermion in four-dimensional theory. We investigate the effect of introducing torsion on the internal manifold and find that there are massless fermions. The hope is that given an isometry group the representation to which these fermions belong is fixed, in contrast to the situation in Yang--Mills theory. We show that this is indeed the case, but the representations do not appear to be the ones favored by current theoretical prejudice. The cases with parallelizable torsions on a group manifold as the internal manifold are analyzed in detail

Some Exact Solutions for a Klein Gordon Equation Algunas soluciones exactas para una ecuación de Klein Gordon

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H H Ortíz Álvarez

2012-12-01

Full Text Available In solving practical problems in science and engineering arises as a direct consequence differential equations that explains the dynamics of the phenomena.Finding exact solutions to this equations provides importan informationabout the behavior of physical systems. The Lie symmetry method allows tofind invariant solutions under certain groups of transformations for differentialequations.This method not very well known and used is of great importance inthe scientific community. By this approach it was possible to find several exactinvariant solutions for the Klein Gordon Equation uxx − utt = k(u. A particularcase, The Kolmogorov equation uxx − utt = k1u + k2un was considered.These equations appear in the study of relativistic and quantum physics. Thegeneral solutions found, could be used for future explorations on the study forother specific K(u functions. En la solución de problemas prácticos de las ciencias y la ingeniería surgen como consecuencia directa ecuaciones diferenciales que dan razón de la dinámica de los fenómenos. El encontrar soluciones exactas a estas ecuaciones proporciona información importante sobre el comportamiento de sistemas físicos. El método de las simetrías de Lie permite encontrar soluciones invariantes bajo ciertos grupos de transformaciones para ecuaciones diferenciales. Mediante este método fue posible encontrar familias de soluciones exactas invariantes para la ecuación de Klein Gordon uxx- utt = k(u: En particular, se consideró la ecuación de Kolmogorov uxx - utt = k1u + k2u n. Estas ecuaciones aparecen en el estudio de la física relativista y cuántica. Las soluciones generales encontradas podrían emplearse en futuros desarrollos en el estudio para otro tipo de funciones k(u.

Distribution and diversity of aquatic macroinvertebrate assemblages in a semi-arid region earmarked for shale gas exploration (Eastern Cape Karoo, South Africa.

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Annah Mabidi

Full Text Available This study aims to investigate macroinvertebrate assemblage structure and composition across the three major waterbody types (temporary rivers, depression wetlands and semi-permanent dams of the Eastern Cape Karoo, and to identify important environmental and spatial correlates of macroinvertebrate assemblage composition in the region. A total of 33 waterbodies (9 dams, 13 depression wetlands and 11 rivers were sampled. Altogether, 91 taxa were recorded in November 2014 and 82 in April 2015. Twenty-seven taxa were common to all three waterbody types (across both sampling occasions, with 17 of these observed in November and 19 in April. The ANOSIM tests revealed significant differences in assemblage composition between the depression wetlands and rivers for both sampling occasions, but dams did not differ from the other waterbody types. SIMPER analyses indicated that the notonectid Anisops varia and the corixid Micronecta scutellaris were abundant across all three waterbody types during both sampling occasions. The mayfly Cloeon africanum and the damselfly Pseudagrion sp. were abundant in river habitats during both sampling occasions, while the gastropod mollusc Bulinus tropicus and the copepod Lovenula falcifera best characterised depression wetlands on both occasions. Non-metric multidimensional scaling ordination highlighted a clear separation of assemblages between November and April, while distance-based Redundancy Analysis revealed that conductivity, altitude, turbidity and pH were the most important variables explaining the variation in macroinvertebrate assemblage patterns. These results provide baseline information which is important for future biological monitoring of impacts associated with hydraulic fracturing activities and climatic changes in the region.

Separable coordinates and particle creation I: the klein-Gordon equation

International Nuclear Information System (INIS)

Costa, Isaias

1987-01-01

A very simple derivation of the 10 orthogonal coordinate systems where the Klein-Gordon equation separates is presented. It is based on the conformal structure of the two dimensional Minkowski space. Horizons, proper time and acceleration of abserves that follow the time coordinate line, as well as other physical properties of the systems, are obtained. The relevance of these coordinates is discussed, specially in the context of quantum field theory in curved space. (author) [pt

On the infinite-dimensional spin-2 symmetries in Kaluza-Klein theories

International Nuclear Information System (INIS)

Hohm, O.; Hamburg Univ.

2005-11-01

We consider the couplings of an infinite number of spin-2 fields to gravity appearing in Kaluza-Klein theories. They are constructed as the broken phase of a massless theory possessing an infinite-dimensional spin-2 symmetry. Focusing on a circle compactification of four-dimensional gravity we show that the resulting gravity/spin-2 system in D=3 has in its unbroken phase an interpretation as a Chern-Simons theory of the Kac-Moody algebra iso(1,2) associated to the Poincare group and also fits into the geometrical framework of algebra-valued differential geometry developed by Wald. Assigning all degrees of freedom to scalar fields, the matter couplings in the unbroken phase are determined, and it is shown that their global symmetry algebra contains the Virasoro algebra together with an enhancement of the Ehlers group SL(2,R) to its affine extension. The broken phase is then constructed by gauging a subgroup of the global symmetries. It is shown that metric, spin-2 fields and Kaluza-Klein vectors combine into a Chern-Simons theory for an extended algebra, in which the affine Poincare subalgebra acquires a central extension. (orig.)

Revisiting of etiology, clinical picture and diagnosis of the Kleine-Levin syndrome.

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Ulyanova О.V.

2017-03-01

Full Text Available Objective: to draw the attention to the Kleine - Levin syndrome (SKL, a rare, poorly understood disease, not only in Russia but throughout the world. We analyzed the case of the 23-year old patient M, with the Kleine — Levin syndrome. SKL belongs to the group of recurrent hypersomnia and is characterized by long bouts of sleep lasting an average of 10-14 days, beginning with the imperative and difficulty awakening. During bouts of sleep observed unusual behavior of patients: hyperphagia; hypersexuality in males; irritability, restlessness, impaired mental activity; aggression; feeling of unreality of it all; confusion, hallucinatory episodes and depression in females. During wakefulness, marked dyspho-ria, emotional stupefaction, loss of memory. The syndrome develops in 4 times more often in men than in women, aged 12-25 years. Etiological factors: brain tumor, head trauma, metabolic disorders, acute infectious diseases with fever. Often the development of the syndrome is preceded by hyperemia and hypothalamic-pituitary dysfunction. The article discussed the etiology, diagnosis, and possible combinations of clinical manifestations in SKL.

A preliminary analysis of the groundwater recharge to the Karoo formations, mid-Zambesi basin, Zimbabwe

DEFF Research Database (Denmark)

Larsen, Flemming; Owen, R.; Dahlin, T.

2002-01-01

A multi-disciplinary study is being carried out on recharge to the Karoo sandstone aquifer in the western part of Zimbabwe, where recharge is controlled by the presence of a thick, confining basalt layer. The aquifer is geographically extensive, and has been identified throughout the southern part......, before it dips below an impervious basalt cover. However, resistivity profiling shows that the basalt at the basin margin is weathered and fractured, and probably permeable, while the basalt deeper into the basin is fresh, solid and impermeable. Field and laboratory analysis of 22 groundwater samples......–130 mm/yr, with an average value of 25 mm/yr. Preliminary results of recharge estimate using 36Cl data suggests lower direct infiltration rates, but further studies are needed. The combination of hydro-chemical, isotopic and geophysical investigations show that the recharge area extends well beyond...

Klein bottle logophysics: a unified principle for non-linear systems, cosmology, geophysics, biology, biomechanics and perception

Science.gov (United States)

Lucio Rapoport, Diego

2013-04-01

We present a unified principle for science that surmounts dualism, in terms of torsion fields and the non-orientable surfaces, notably the Klein Bottle and its logic, the Möbius strip and the projective plane. We apply it to the complex numbers and cosmology, to non-linear systems integrating the issue of hyperbolic divergences with the change of orientability, to the biomechanics of vision and the mammal heart, to the morphogenesis of crustal shapes on Earth in connection to the wavefronts of gravitation, elasticity and electromagnetism, to pattern recognition of artificial images and visual recognition, to neurology and the topographic maps of the sensorium, to perception, in particular of music. We develop it in terms of the fundamental 2:1 resonance inherent to the Möbius strip and the Klein Bottle, the minimal surfaces representation of the wavefronts, and the non-dual Klein Bottle logic inherent to pattern recognition, to the harmonic functions and vector fields that lay at the basis of geophysics and physics at large. We discuss the relation between the topographic maps of the sensorium, and the issue of turning inside-out of the visual world as a general principle for cognition, topological chemistry, cell biology and biological morphogenesis in particular in embryology

Klein bottle logophysics: a unified principle for non-linear systems, cosmology, geophysics, biology, biomechanics and perception

International Nuclear Information System (INIS)

Rapoport, Diego Lucio

2013-01-01

We present a unified principle for science that surmounts dualism, in terms of torsion fields and the non-orientable surfaces, notably the Klein Bottle and its logic, the Möbius strip and the projective plane. We apply it to the complex numbers and cosmology, to non-linear systems integrating the issue of hyperbolic divergences with the change of orientability, to the biomechanics of vision and the mammal heart, to the morphogenesis of crustal shapes on Earth in connection to the wavefronts of gravitation, elasticity and electromagnetism, to pattern recognition of artificial images and visual recognition, to neurology and the topographic maps of the sensorium, to perception, in particular of music. We develop it in terms of the fundamental 2:1 resonance inherent to the Möbius strip and the Klein Bottle, the minimal surfaces representation of the wavefronts, and the non-dual Klein Bottle logic inherent to pattern recognition, to the harmonic functions and vector fields that lay at the basis of geophysics and physics at large. We discuss the relation between the topographic maps of the sensorium, and the issue of turning inside-out of the visual world as a general principle for cognition, topological chemistry, cell biology and biological morphogenesis in particular in embryology

Operational Solution to the Nonlinear Klein-Gordon Equation

Science.gov (United States)

Bengochea, G.; Verde-Star, L.; Ortigueira, M.

2018-05-01

We obtain solutions of the nonlinear Klein-Gordon equation using a novel operational method combined with the Adomian polynomial expansion of nonlinear functions. Our operational method does not use any integral transforms nor integration processes. We illustrate the application of our method by solving several examples and present numerical results that show the accuracy of the truncated series approximations to the solutions. Supported by Grant SEP-CONACYT 220603, the first author was supported by SEP-PRODEP through the project UAM-PTC-630, the third author was supported by Portuguese National Funds through the FCT Foundation for Science and Technology under the project PEst-UID/EEA/00066/2013

Loop groups, Kaluza-Klein reduction and M-theory

International Nuclear Information System (INIS)

Bergman, Aaron; Varadarajan, Uday

2005-01-01

We show that the data of a principal G-bundle over a principal circle bundle is equivalent to that of a LG-circumflex (def)/= U(1) x LG-bundle over the base of the circle bundle. We apply this to the Kaluza-Klein reduction of M-theory to IIA and show that certain generalized characteristic classes of the loop group bundle encode the Bianchi identities of the antisymmetric tensor fields of IIA supergravity. We further show that the low dimensional characteristic classes of the central extension of the loop group encode the Bianchi identities of massive IIA, thereby adding support to the conjectures given elsewhere

Universal extra dimensions and Kaluza-Klein bound states

International Nuclear Information System (INIS)

Carone, Christopher D.; Conroy, Justin M.; Sher, Marc; Turan, Ismail

2004-01-01

We study the bound states of the Kaluza-Klein (KK) excitations of quarks in certain models of universal extra dimensions. Such bound states may be detected at future lepton colliders in the cross section for the pair production of KK quarks near threshold. For typical values of model parameters, we find that 'KK quarkonia' have widths in the 10-100 MeV range, and production cross sections of the order of a few picobarns for the lightest resonances. Two body decays of the constituent KK quarks lead to distinctive experimental signatures. We point out that such KK resonances may be discovered before any of the higher KK modes

Transport and Quantum Coherence in Graphene Rings: Aharonov-Bohm Oscillations, Klein Tunneling, and Particle Localization

Science.gov (United States)

Filusch, Alexander; Wurl, Christian; Pieper, Andreas; Fehske, Holger

2018-06-01

Simulating quantum transport through mesoscopic, ring-shaped graphene structures, we address various quantum coherence and interference phenomena. First, a perpendicular magnetic field, penetrating the graphene ring, gives rise to Aharonov-Bohm oscillations in the conductance as a function of the magnetic flux, on top of the universal conductance fluctuations. At very high fluxes, the interference gets suppressed and quantum Hall edge channels develop. Second, applying an electrostatic potential to one of the ring arms, nn'n- or npn-junctions can be realized with particle transmission due to normal tunneling or Klein tunneling. In the latter case, the Aharonov-Bohm oscillations weaken for smooth barriers. Third, if potential disorder comes in to play, both Aharonov-Bohm and Klein tunneling effects rate down, up to the point where particle localization sets in.

Entanglement between smeared field operators in the Klein-Gordon vacuum

International Nuclear Information System (INIS)

Zych, Magdalena; Costa, Fabio; Kofler, Johannes; Brukner, Caslav

2010-01-01

Quantum field theory is the application of quantum physics to fields. It provides a theoretical framework widely used in particle physics and condensed matter physics. One of the most distinct features of quantum physics with respect to classical physics is entanglement or the existence of strong correlations between subsystems that can even be spacelike separated. In quantum fields, observables restricted to a region of space define a subsystem. While there are proofs on the existence of local observables that would allow a violation of Bell's inequalities in the vacuum states of quantum fields as well as some explicit but technically demanding schemes requiring an extreme fine-tuning of the interaction between the fields and detectors, an experimentally accessible entanglement witness for quantum fields is still missing. Here we introduce smeared field operators which allow reducing the vacuum to a system of two effective bosonic modes. The introduction of such collective observables is motivated by the fact that no physical probe has access to fields in single spatial (mathematical) points but rather smeared over finite volumes. We first give explicit collective observables whose correlations reveal vacuum entanglement in the Klein-Gordon field. We then show that the critical distance between the two regions of space above which two effective bosonic modes become separable is of the order of the Compton wavelength of the particle corresponding to the massive Klein-Gordon field.

Sulla domanda di economia irrazionale: Naomi Klein vs. Milton Friedman

OpenAIRE

Filoso, Valerio

2008-01-01

The persistence of demand for economic irrationality, as expressed by the big success gained by the literature on no-globalism, is an empirical puzzle and the recent book by Naomi Klein The Shock Doctrine (2007) is a rampant example. An explanation for this anomaly is provided by the theory of rational irrationality (Caplan, 2007). While in the field of natural sciences confutation of wrong theories sets them apart forever, in the field of economics rebutted theories can still have an appeal ...

Melanie Klein, una princesa que creó su propio reino

OpenAIRE

Vallejo Orellana, Reyes; Sánchez-Barranco Ruiz, Antonio

2004-01-01

Las formulaciones kleinianas no pueden ser encuadradas como un mero desarrollo del psicoanálisis freudiano, dado que suponen cambios radicales en su metapsicología, núcleo intocable del sistema. En todo caso, Melanie Klein merece un lugar de privilegio entre las mujeres pioneras que aportaron ideas originales a la psicología del inconsciente y aunque siempre se autoconsideró una fiel seguidora de Freud, terminó desarrollando su propio reino. Melanie Klein’s formulations should not be frame...

Anastomosing river deposits: palaeoenvironmental control on coal quality and distribution, Northern Karoo Basin

Energy Technology Data Exchange (ETDEWEB)

Cairncross, B

1980-01-01

Borehole data from an area close to the northern margin of the Karoo Basin 110 m thick coal reveal a bearing succession of the Vryheid Formation overlying Dwyka tillite. The lowermost sediments reflect processes of deglaciation with a complex array of glaciolacustrine, glaciofluvial and alluvial-outwash fan deposits. Above this paraglacial milieu, tundra-type peat bogs developed in inactive areas and account for the two thick basal coal seams (No. 1 and 2 seams). During accumulation of peat which was later to form the extensive No. 2 coal seam, active clastic sedimentation was confined to laterally restricted river channels which incised into the underlying peat. Lateral migration was inhibited by vegetation stabilized river banks and channel deposits are characterized by vertically accreted upward-fining cycles. Channel fill consists of coarse-grinder bedload sediment deposited in anastomosing streams. Flood episodes are marked by widespread, but thin (< 1 m), shale zones that intercalate with the channel sandstones. Both sandstone and shale units are completely enveloped by No. 2 coal seams. This clastic parting influences No. 2 coal seam distribution and ash content. 23 references

Algunas contribuciones a la teoría de Kaluza-Klein

OpenAIRE

Griego, Jorge

1997-01-01

Esta tesis se propone avanzar en la comprensión de distintos problemas que se plantean en la teoría de Kaluza-Klein, vinculados básicamente con la física que ven observadores impedidos de acceder a una parte de su universo. Por un lado, nos proponemos mostrar que existe evidencia experimental directa de las dimensiones compactificadas a nivel espacio-tiempo efectivo. Mostraremos que ciertos fenómenos cuánticos (pero de naturaleza esencialmente electromagnética) pueden ser interpreta...

Production Of The ADD Type Kaluza-Klein Excitations At Future e+e-, ep And pp Colliders

International Nuclear Information System (INIS)

Billur, A. A.; Ciftci, A. K.; Ciftci, R.; Inan, S. C.; Sultansoy, S.

2007-01-01

Possible production of ADD type Kaluza-Klein excitations are investigated at future high energy e+e-, ep and pp colliders. Discovery limits and signatures of such excitations are discussed at above colliders comparatively

African Zoology - Vol 48, No 1 (2013)

African Journals Online (AJOL)

Residency and small-scale movement behaviour of three endemic sparid fishes in their shallow rocky subtidal nursery habitat, South Africa · EMAIL FULL TEXT ... Seasonal and daily activity patterns of leopard tortoises (Stigmochelys pardalis Bell, 1828) on farmland in the Nama-Karoo, South Africa · EMAIL FULL TEXT ...

Feeling unreal: a functional imaging study in patients with Kleine-Levin syndrome.

Science.gov (United States)

Kas, Aurelie; Lavault, Sophie; Habert, Marie-Odile; Arnulf, Isabelle

2014-07-01

Kleine-Levin syndrome is characterized by relapsing-remitting episodes of severe hypersomnia, cognitive impairment, apathy, derealization and behavioural disturbances. Between episodes, patients have normal sleep, mood and behaviour. Functional imaging studies performed in small series of patients with Kleine-Levin syndrome with visual or semi-quantitative, uncontrolled analysis yielded equivocal brain changes. Using whole brain voxel-based group analysis, we compared brain perfusion scintigraphy during and between episodes in consecutive patients with Kleine-Levin syndrome versus healthy control subjects and correlated perfusion changes with disease severity and symptoms, focusing on less studied but disabling symptoms, such as apathy and derealization. During asymptomatic periods, 41 patients (mean age of 22.3 ± 8.1 years, 56.1% male) and 15 age- and sex-matched healthy control subjects underwent single-photon emission computed tomography scanning with technetium-99m ethyl cysteinate dimer. Eleven patients repeated the test during a symptomatic period. Compared with controls, patients during asymptomatic periods had persistent hypoperfusion in the hypothalamus, the thalamus (mainly the right posterior part), the caudate nucleus, and cortical associative areas, including the anterior cingulate, (Brodmann area 25), the orbito-frontal (Brodmann area 11) and the right superior temporal cortices (Brodmann area 22), extending to the insula (P area). Two additional hypoperfused areas emerged during symptomatic periods (P Brodmann area 8) and the right parieto-temporal junction (Brodmann areas 22 and 39). These two areas were more affected between episodes, when the mean episode duration was longer (r = -0.53; P area may underlie the striking derealization reported by patients during episodes. Defects in the dorsomedial prefrontal cortex may cause apathy. Persistent hypoperfusion in the diencephalic and associative cortical area during asymptomatic periods is a marker

Dixon-Souriau equations from a 5-dimensional spinning particle in a Kaluza-Klein framework

International Nuclear Information System (INIS)

Cianfrani, F.; Milillo, I.; Montani, G.

2007-01-01

The dimensional reduction of Papapetrou equations is performed in a 5-dimensional Kaluza-Klein background and Dixon-Souriau results for the motion of a charged spinning body are obtained. The splitting provides an electric dipole moment, and, for elementary particles, the induced parity and time-reversal violations are explained

Bound State Solutions of the Klein-Gordon Equation for the Mathews-Lakshmanan Oscillator

International Nuclear Information System (INIS)

Schulze-Halberg, Axel; Wang, Jie

2014-01-01

We study a boundary-value problem for the Klein-Gordon equation that is inspired by the well-known Mathews-Lakshmanan oscillator model. By establishing a link to the spheroidal equation, we show that our problem admits an infinite number of discrete energies, together with associated solutions that form an orthogonal set in a weighted L 2 -Hilbert space. (author)

Klein tunneling in carbon nanostructures: A free-particle dynamics in disguise

International Nuclear Information System (INIS)

Jakubsky, Vit; Nieto, Luis-Miguel; Plyushchay, Mikhail S.

2011-01-01

The absence of backscattering in metallic nanotubes as well as perfect Klein tunneling in potential barriers in graphene are the prominent electronic characteristics of carbon nanostructures. We show that the phenomena can be explained by a peculiar supersymmetry generated by a first order Hamiltonian and zero-order supercharge operators. Like the supersymmetry associated with second order reflectionless finite-gap systems, it relates here the low-energy behavior of the charge carriers with the free-particle dynamics.

Partial Internal Control Recovery on 1-D Klein-Gordon Systems

Directory of Open Access Journals (Sweden)

Iwan Pranoto

2010-03-01

Full Text Available In this exposition, a technique to recover internal control on a distributed parameter system is reported. The system is described by 1-D Klein-Gordon partial differential equation with a time-varying parameter. We would like to recover the internal control applied to the system if we know some limited information about the output. We use a method called sentinel method to recover the internal control. It involves some construction of a linear functional, and we show that this construction relates closely to the exact controllability problem.

Non-existence of global solutions to generalized dissipative Klein-Gordon equations with positive energy

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Maxim Olegovich Korpusov

2012-07-01

Full Text Available In this article the initial-boundary-value problem for generalized dissipative high-order equation of Klein-Gordon type is considered. We continue our study of nonlinear hyperbolic equations and systems with arbitrary positive energy. The modified concavity method by Levine is used for proving blow-up of solutions.

Thinking out the Box: Promoting Inter-jurisdictional Collaboration in ...

African Journals Online (AJOL)

The issue of inter-jurisdictional collaboration is explored with reference to the Karoo region of South Africa. This region has not reached its economic potential, because it straddles four provinces. Nevertheless, there are positive signs of a new appreciation of regionalism in South Africa, in terms of academic analyses, civil ...

Positive energy theorem in generalized Kaluza-Klein theories of higher dimensions

International Nuclear Information System (INIS)

Moreschi, O.M.

1983-01-01

The technique of using spinors in the proof of positive energy theorems in 4 dimensions is extended to the case of Kaluza-Klein theories in spaces of 4 + n dimensions. First a useful presentation of generalized Kaluza-Klein theories is introduced, in which just from the observation of conformal symmetries it is possible to detect a nice splitting of the Ricci tensor into a 4-dimensional Ricci part and a Yang-Mills part, among others. Consideration of linear dependence among the symmetries is not excluded in this treatment. Relevant to the introduction of spinors, a discussion of Clifford Algebras is presented. In particular a real representation of these algebras is introduced for spaces of higher dimensions and its structure is analyzed. The Lie derivative of spinors is presented probably more clearly than in former treatments. After the introduction of these preliminary themes, a brief review of the relevant aspects of positive energy theorems in 4 dimensions is presented, followed by the extension of these ideas to the case of 5 dimensions. Here an earlier result involving gravitational mass and electromagnetic charges is improved. Finally the results are generalized to spaces of 4 + n dimensions, and a more complicated condition to be satisfied by the usual matter tensor is discovered. This procedure leads to a natural definition of invariant Yang-Mills charges, which is compared with former studies

Bioclimatological rating of cities and resorts in South Africa according to the Climate Index

Science.gov (United States)

Becker, S.

2000-10-01

The climatic conditions of 31 cities and resorts in South Africa have been examined with regard to the thermal perception of people. The evaluation of the thermal conditions is based on the human energy balance calculations, which have been specified for the detection of hot or cold discomfort of people walking outdoors in spite of adapted clothing. Hot days and cold days are defined depending on the extent and duration of thermal discomfort. Cities are rated according to the Climate Index (CI), which is defined in terms of the monthly frequency of hot or cold days. The most pleasant conditions in the annual average can be found along the coastal belt (Port St. Johns, Richards Bay, St. Lucia), the most unpleasant ones in the mediterranean region around Cape Town, the Karoo and the eastern lowveld.

Conférence | À quelle distance sommes-nous des Lumières ? | Etienne Klein et François-Xavier Verger | 4 mars

CERN Multimedia

2015-01-01

À quelle distance sommes-nous des Lumières ?, par Etienne Klein et François-Xavier Verger.   Mercredi 4 mars 2015 à 20h30 Globe de la science et de l'innovation Route de Meyrin, 1211 Genève Soirée en français Etienne Klein : L'esprit des Lumières promeut l’autonomie de l’entendement et la primauté de l’esprit scientifique. Il pose également la finalité humaine de nos actes – on ne vise pas Dieu, mais les hommes –, et l’universalité, notamment celle des droits de l’homme. Nous nous considérons volontiers comme les héritiers des Lumières. Mais à quelle distance sommes-nous réellement de leur esprit ? Etienne Klein est physicien, directeur de recherches au CEA et docteur en philosophie des sciences. Il est professeur &a...

Construction of wave operator for two-dimensional Klein-Gordon-Schrodinger systems with Yukawa coupling

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Kai Tsuruta

2013-05-01

Full Text Available We prove the existence of the wave operator for the Klein-Gordon-Schrodinger system with Yukawa coupling. This non-linearity type is below Strichartz scaling, and therefore classic perturbation methods will fail in any Strichartz space. Instead, we follow the "first iteration method" to handle these critical non-linearities.

The homology groups of moduli spaces on non-classical Klein surfaces

International Nuclear Information System (INIS)

Zaw, Myint

2001-08-01

We describe the moduli space M-vector±(g,c) of non-classical directed Klein surfaces of genus g=h-c-1 with c≥0 distinguished points as a configuration space B ± (h,c) of classes h-slit pairs in C. Based on this model, we prove that M-vector ± (g,c) is non-orientable for any g and c and we compute the homology groups of the moduli spaces M-vector ± (g,c) for g≤2. (author)

SOLVING NONLINEAR KLEIN-GORDON EQUATION WITH A QUADRATIC NONLINEAR TERM USING HOMOTOPY ANALYSIS METHOD

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H. Jafari

2010-07-01

Full Text Available In this paper, nonlinear Klein-Gordon equation with quadratic term is solved by means of an analytic technique, namely the Homotopy analysis method (HAM.Comparisons are made between the Adomian decomposition method (ADM, the exact solution and homotopy analysis method. The results reveal that the proposed method is very effective and simple.

Chaotic oscillations of the Klein-Gordon equation with distributed energy pumping and van der Pol boundary regulation and distributed time-varying coefficients

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Bo Sun

2014-09-01

Full Text Available Consider the Klein-Gordon equation with variable coefficients, a van der Pol cubic nonlinearity in one of the boundary conditions and a spatially distributed antidamping term, we use a variable-substitution technique together with the analogy with the 1-dimensional wave equation to prove that for the Klein-Gordon equation chaos occurs for a class of equations and boundary conditions when system parameters enter a certain regime. Chaotic and nonchaotic profiles of solutions are illustrated by computer graphics.

Quadratic algebras applied to noncommutative integration of the Klein-Gordon equation: Four-dimensional quadratic algebras containing three-dimensional nilpotent lie algebras

International Nuclear Information System (INIS)

Varaksin, O.L.; Firstov, V.V.; Shapovalov, A.V.

1995-01-01

The study is continued on noncommutative integration of linear partial differential equations in application to the exact integration of quantum-mechanical equations in a Riemann space. That method gives solutions to the Klein-Gordon equation when the set of noncommutative symmetry operations for that equation forms a quadratic algebra consisting of one second-order operator and of first-order operators forming a Lie algebra. The paper is a continuation of, where a single nontrivial example is used to demonstrate noncommutative integration of the Klein-Gordon equation in a Riemann space not permitting variable separation

Production of the Randall-Sundrum Type Kaluza-Klein Excitations at Future e+e-, ep and pp Colliders

International Nuclear Information System (INIS)

Billur, A. A.; Ciftci, A. K.; Ciftci, R.; Inan, S. C.; Sultansoy, S.

2007-01-01

Possible production of Randall-Sundrum type Kaluza-Klein excitations are investigated at future high energy e+e-, ep and pp colliders. Discovery limits and signatures of such excitations are discussed at above colliders comparatively

Kaluza-Klein gravity and scalar-tensor theories

International Nuclear Information System (INIS)

Chauvineau, Bertrand

2007-01-01

In this paper, we propose a Kaluza-Klein approach to gravity in Δ=4+n 1 +n 2 +... dimensions, where n 1 ,n 2 ,... are the dimensions of independent internal spaces. One is interested in the case where each internal metric depends on the four-dimensional coordinates by a conformal factor. If all these conformal factors depend on the four-dimensional coordinates through a common scalar function Ψ, the induced effective four-dimensional gravity theory turns out to be of general scalar-tensor type. One shows that, if there are at least two internal spaces, the theory is not ruled out by experimental tests on gravitation, even if there is no massive scalar-potential term in the effective four-dimensional Lagrangian (contrary to what happens if there is only one internal space, in which case ω is of order unity, whatever the dimension of this internal space)

Killing–Yano symmetry of Kaluza–Klein black holes in five dimensions

International Nuclear Information System (INIS)

Houri, Tsuyoshi; Yamamoto, Kei

2013-01-01

Using a generalized Killing–Yano equation in the presence of torsion, spacetime metrics admitting a rank-2 generalized Killing–Yano tensor are investigated in five dimensions under the assumption that its eigenvector associated with the zero eigenvalue is a Killing vector field. It is shown that such metrics are classified into three types and the corresponding local expressions are given explicitly. It is also shown that they cover some classes of charged, rotating Kaluza–Klein black hole solutions of minimal supergravity and Abelian heterotic supergravity. (paper)

Quadratic algebras and noncommutative integration of Klein-Gordon equations in non-steckel Riemann spaces

International Nuclear Information System (INIS)

Varaksin, O.L.; Firstov, V.V.; Shapovalov, A.V.; Shirokov, I.V.

1995-01-01

The method of noncommutative integration of linear partial differential equations is used to solve the Klein-Gordon equations in Riemann space, in the case when the set of noncommutating symmetry operators of this equation for a quadratic algebra consists of one second-order operator and several first-order operators. Solutions that do not permit variable separation are presented

Periodic travelling and non-travelling wave solutions of the nonlinear Klein-Gordon equation with imaginary mass

International Nuclear Information System (INIS)

Tang Xiaoyan; Shukla, Padma Kant

2008-01-01

Exact solutions, including the periodic travelling and non-travelling wave solutions, are presented for the nonlinear Klein-Gordon equation with imaginary mass. Some arbitrary functions are permitted in the periodic non-travelling wave solutions, which contribute to various high dimensional nonlinear structures

Microcanonical algorithm of carged roteting dilatonic black holes from the viewpoint of the Kaluza-Klein theory

CERN Document Server

Fujisaki, H

2003-01-01

Microcanonical ensemble paradigm is described in proper reference to the thermal aspect of the extremal state for a dilute gas of charged rotating black holes coupled to a dilaton field on the basis of the boosted Kerr solution of the Kaluza-Klein theory.

Spherically symmetric solutions in abelian Kaluza-Klein theories

International Nuclear Information System (INIS)

Angus, I.G.

1986-01-01

We present the most general spherically symmetric solution to the field equations of the truncated five-dimensional Kaluza-Klein theory. We also detail some of the special forms of this solution. With the exception of the Gross-Perry-Sorkin monopole and the Schwarzschild solutions we find that most, and we conjecture all, of the solutions have naked curvature singularities. We then proceed to consider higher-dimensional theories with toroidal compactification and we exhibit a class of nonsingular monopole solutions which are the natural generalization of the Gross-Perry-Sorkin monopole to more than five dimensions. We also present some selected solutions including a solution pertaining to a model with a Ricci-flat, but not curvature-flat, internal manifold. All of these other solutions have naked curvature singularities. (orig.)

On the stationary Einstein-Maxwell-Klein-Gordon equations

International Nuclear Information System (INIS)

Gegenberg, J.D.

1981-05-01

The stationary Einstein-Maxwell-Klein-Gordon (EMKG) equations for interacting gravitational, electromagnetic and meson fields are examined. The theory is cast into the formalism of principal fiber bundles with a connection, wherein its relationship to current trends in theoretical physics is made manifest. The EMKG equations are shown to admit a Higgs-like mechanism for giving mass to the gauge field. A theorem specifying sufficient conditions for the stationarity of the spacetime metric to imply stationarity of the other fields is proved. By imposing additional constraints and symmetries, the EMKG equations are considerably simplified. An attempt is made to apply a solution-generation technique, and this meets with only partial success. Finally, a stationary but non-static solution is found, and the geometric and physical properties are discussed

The XRD Amorphous Component in John Klein Drill Fines at Yellowknife Bay, Gale Crater, Mars

Science.gov (United States)

Morris, Richard V.; Ming,, Douglas W.; Blake, David; Vaniman, David; Bish, David L; Chipera, Steve; Downs, Robert; Morrison, Shaunna; Gellert, Ralf; Campbell, Iain;

Stable isotope ratio analysis: A potential analytical tool for the authentication of South African lamb meat.

Science.gov (United States)

Erasmus, Sara Wilhelmina; Muller, Magdalena; van der Rijst, Marieta; Hoffman, Louwrens Christiaan

2016-02-01

Stable isotope ratios ((13)C/(12)C and (15)N/(14)N) of South African Dorper lambs from farms with different vegetation types were measured by isotope ratio mass spectrometry (IRMS), to evaluate it as a tool for the authentication of origin and feeding regime. Homogenised and defatted meat of the Longissimus lumborum (LL) muscle of lambs from seven different farms was assessed. The δ(13)C values were affected by the origin of the meat, mainly reflecting the diet. The Rûens and Free State farms had the lowest (p ⩽ 0.05) δ(15)N values, followed by the Northern Cape farms, with Hantam Karoo/Calvinia having the highest δ(15)N values. Discriminant analysis showed δ(13)C and δ(15)N differences as promising results for the use of IRMS as a reliable analytical tool for lamb meat authentication. The results suggest that diet, linked to origin, is an important factor to consider regarding region of origin classification for South African lamb. Copyright © 2015 Elsevier Ltd. All rights reserved.

Symmetric and arbitrarily high-order Birkhoff-Hermite time integrators and their long-time behaviour for solving nonlinear Klein-Gordon equations

Science.gov (United States)

Liu, Changying; Iserles, Arieh; Wu, Xinyuan

2018-03-01

The Klein-Gordon equation with nonlinear potential occurs in a wide range of application areas in science and engineering. Its computation represents a major challenge. The main theme of this paper is the construction of symmetric and arbitrarily high-order time integrators for the nonlinear Klein-Gordon equation by integrating Birkhoff-Hermite interpolation polynomials. To this end, under the assumption of periodic boundary conditions, we begin with the formulation of the nonlinear Klein-Gordon equation as an abstract second-order ordinary differential equation (ODE) and its operator-variation-of-constants formula. We then derive a symmetric and arbitrarily high-order Birkhoff-Hermite time integration formula for the nonlinear abstract ODE. Accordingly, the stability, convergence and long-time behaviour are rigorously analysed once the spatial differential operator is approximated by an appropriate positive semi-definite matrix, subject to suitable temporal and spatial smoothness. A remarkable characteristic of this new approach is that the requirement of temporal smoothness is reduced compared with the traditional numerical methods for PDEs in the literature. Numerical results demonstrate the advantage and efficiency of our time integrators in comparison with the existing numerical approaches.

Facts, theories and ideologies: Viola Klein and Sociology of Scientific Knowledge

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Eulalia Pérez Sedeño

2012-07-01

Full Text Available Several studies on history, philosophy and sociology of science have demonstrated that science is not autonomous and value-neutral and its selfless search of truth is an ideal theoretical myth far from the real practice of science, which is an aggregate of social practices. Viola Klein was a pioneer in studying science using the same instruments and categories utilized in any other social practice. The aim of this work is to highlight her contributions to Sociology of Scientific Knowledge at a moment when this discipline was, at the most, incipient.

Kleine-Levine syndrome in an adolescent female and response to modafinil

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Aggarwal Ashish

2011-01-01

Full Text Available Kleine-Levine Syndrome (KLS is a disorder characterized by a triad of periodic hypersomnia, hyperphagia, and hypersexuality. KLS, although more common in young males, it has also been seen in females. Treatment options available for its management include mood stabilisers like lithium, stimulants like amphetamines, antidepressants and other options including electroconvulsive therapy. Modafinil is one of the new stimulant medications approved for narcolepsy. Herein, we report a young female with KLS and showing favorable response to modafinil. More data is required to establish the effectiveness of modafinil in this syndrome.

[The difficult concept of "internal objects" (1934-1943). Its significance for the formation of the Klein group].

Science.gov (United States)

Hinshelwood, R D

1996-06-01

Although the concept of "inner objects" developed by Melanie Klein is hardly a major object of discussion today, it caused a furore in the ranks of the British Psychoanalytical Society in the thirties and forties. Notably the analysts from Vienna were unable to agree to the existence of inner objects engendered via processes of internalisation. The author traces the course of these discussions of a clinical problem and the confusion they caused, placing them at the same time in a specific historical context. He sees the controversy as the expression of conflicts and fears unsettling the British Psychoanalytical Society during that period, caused on the one hand by the necessary integration of the exiled Freud family and on the other by tensions within its own ranks leading ultimately to a division of the Society and the constitution of the Klein Group.

Approximate analytical solutions of Klein-Gordon equation with Hulthen potentials for nonzero angular momentum

International Nuclear Information System (INIS)

Chen Changyuan; Sun Dongsheng; Lu Falin

2007-01-01

Using the exponential function transformation approach along with an approximation for the centrifugal potential, the radial Klein-Gordon equation with the vector and scalar Hulthen potential is transformed to a hypergeometric differential equation. The approximate analytical solutions of bound states are attained for different l. The analytical energy equation and the unnormalized radial wave functions expressed in terms of hypergeometric polynomials are given

Topological symmetry breaking of self-interacting fractional Klein-Gordon field theories on toroidal spacetime

International Nuclear Information System (INIS)

Lim, S C; Teo, L P

2008-01-01

Quartic self-interacting fractional Klein-Gordon scalar massive and massless field theories on toroidal spacetime are studied. The effective potential and topologically generated mass are determined using zeta-function regularization technique. Renormalization of these quantities are derived. Conditions for symmetry breaking are obtained analytically. Simulations are carried out to illustrate regions or values of compactified dimensions where symmetry-breaking mechanisms appear

Particle creation effect on M4 X S7 Kaluza-Klein cosmologies

International Nuclear Information System (INIS)

Koikawa, T.; Maeda, K.

1984-01-01

The particle creation effect on the higher-dimensional Kaluza-Klein cosmologies with M 4 xS 7 topology is studied. This quantum effect is found to change the classical behavior of the internal and external scale factors drastically in the early stage of the expansion, so that the dimensional reduction seems to fail. However, at the later stage two scale factors get separated from each other and the internal scale factor approaches the final singularity just like the vacuum case. (orig.)

Patchiness in semi-arid dwarf shrublands: evidence from satellite ...

African Journals Online (AJOL)

... Plants; Remote sensing; Rhigozum obovatum Burch; Satellite-derived vegetation indices; Woody species; patchiness; semi-arid; dwarf shrubland; shrublands; co2; assimilation; karoo; south africa; ndvi; satellite imagery; geochemical mound; rhigozum obovatum; eriocephalus ericoides; pentzia incana; vegetation; botany

Acerca da comunicação: entre Freud (1895 e Klein (1946 On communication: between Freud (1895 and Klein (1946

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Daniel Delouya

2002-06-01

Full Text Available A identificação projetiva foi concebida como modalidade básica da comunicação inconsciente. O trabalho retoma esta primeira formulação para examinar o papel primordial da comunicação na construção da mente, segundo Klein e, de outro lado, do aparelho psíquico do Projeto para uma psicologia (1895, em que Freud reserva a comunicação para o lugar de origem do trilhamento mnêmico do desejo inconsciente.Projective identification was conceived as a prototype mode of unconscious communication. The review of its first formulation permits the investigation of the pivotal role of communication in the construction of the Kleinian mind and, on the other hand, of the psychic apparatus as depicted in Freud's Project (1895 where he assigned communication to the original starting point of the mnemic trajectory of the unconscious desire.

A study of the Higgs effect in the five-dimensional Kaluza-Klein theory

International Nuclear Information System (INIS)

Maheshwari, A.

1985-08-01

The complete expression of the five-dimensional Einstein-Hilbert action as an expansion in fields in the Appelquist-Chodos parametrization of the Kaluza-Klein metric has been given in this paper. It is explicitly shown that a unitary gauge can be fixed in which in each of the charge sectors the vector and the scalar fields are absorbed as Goldstone modes leaving behind the Pauli-Fierz Lagrangian for massive charged spin-2 field. (author)

Long-term subsidence, cooling, and exhumation history along the South Atlantic passive continental margin in NW-Namibia

Science.gov (United States)

Menges, Daniel; Glasmacher, Ulrich Anton; Salomon, Eric; Hackspacher, Peter Christian; Schneider, Gabi

2017-04-01

In northwestern Namibia the Kaoko Belt is one of the most important Precambrian crustal segments that have stored the subsidence, cooling, and exhumation history of Namibia since the Neoproterozoic. ZFT-ages, with ages between 292.7 (46.0) and 436.8 (45.9) Ma, are giving new insights on this early evolution. Paleozoic to Mesozoic sedimentary rocks of the Karoo Supergroup and the Lower Cretaceous volcanic rocks of the Etendeka sequence overlay the Proterozoic metamorphic and intrusive rocks (1). New apatite fission-track (AFT) ages range from 390.9 (17.9) Ma to 80.8 (6.0) Ma. Along the coast apatites of Proterozoic rock samples reveal the youngest ages. Further inland the ages increase significantly. In addition, rapid change of AFT-ages occurs on both sides of major thrust and shear zones. Using the oldest thermochronological data the revealed t-T paths indicate a long era of exhumation, starting at the end of the Pan-African Orogeny in the Neoproterozoic and continuing into the Permo-Carboniferous. The subsequent sedimentation of the Karoo Supergroup initiates a new era of subsidence until the end of Triassic (2).The subsequent period of denudation ends abruptly with the rapid deposition of the Etendeka basalts in the Early Cretaceous (3). The maximum thickness of the Etendeka volcanic suite has been estimated, using the apatite fission-track data, to about 3.2 (1.2) km. With the ongoing opening of the South Atlantic and the formation of the continental margin the Kaoko Belt went through a rapid cooling event starting 130 Ma and ending 80 Ma, at a mean rate of 0.034 km/Ma for the western, and 0.018 km/Ma for the northern and eastern Kaoko Belt. This cooling event was accompanied by a reactivation of major fault zones, like the Purros Mylonite Zone (4). Thereafter, stable conditions were established, with denudation rates generally lower than 0.010 km/Ma, until the Neogene, where a second cooling event led to increased exhumation rates around 0.042 km/Ma. The total

Application of Local Fractional Series Expansion Method to Solve Klein-Gordon Equations on Cantor Sets

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Ai-Min Yang

2014-01-01

Full Text Available We use the local fractional series expansion method to solve the Klein-Gordon equations on Cantor sets within the local fractional derivatives. The analytical solutions within the nondifferential terms are discussed. The obtained results show the simplicity and efficiency of the present technique with application to the problems of the liner differential equations on Cantor sets.

Nuclear spin Hall and Klein tunneling effects during oxidation with electric and magnetic field inductions in graphene.

Science.gov (United States)

Little, Reginald B; McClary, Felicia; Rice, Bria; Jackman, Corine; Mitchell, James W

2012-12-14

The recent observation of the explosive oxidation of graphene with enhancement for decreasing temperature and the requirements for synchronizing oxidants for collective oxidation-reduction (redox) reactions presented a chemical scenario for the thermal harvesting by the magnetic spin Hall Effect. More experimental data are presented to demonstrate such spin Hall Effect by determining the influence of spins of so-called spectator fermionic cations. Furthermore, the so-called spectator bosonic cations are discovered to cause a Klein tunneling effect during the redox reaction of graphene. The Na(+) and K(+), fermionic cations and the Mg(2+) and Ca(2+), bosonic cations were observed and compared under a variety of experimental conditions: adiabatic reactions with initial temperatures (18-22 °C); reactions toward infinite dilution; isothermal reactions under nonadiabatic conditions at low temperature of 18 °C; reactions under paramagnetic O(2) or diamagnetic N(2) atmospheres of different permeabilities; reactions in applied and no applied external magnetic field; and reactions toward excess concentrations of common and uncommon Na(+) and Mg(2+) cations. The observed reaction kinetics and dynamics under these various, diverse conditions are consistent with the spin Hall mechanism, energy harvesting and short time violation of Second Law of Thermodynamics for redox reactions of graphene by the Na(+)K(+) mixture and are consistent with the Klein tunnel mechanism for the redox reactions of graphene by the Mg(2+)Ca(2+) mixture. Mixed spin Hall and Klein tunnel mechanisms are discovered to slow and modulate explosive redox reactions. Such spin Hall Effect also gives explanation of recent tunneling of electrons through boron nitride.

Charge quantization without superheavy masses in a Kaluza--Klein description of electromagnetism

International Nuclear Information System (INIS)

Ross, D.K.

1987-01-01

A scalar matter field coupled to general relativity and electromagnetism in a five-dimensional Kaluza--Klein model is considered. The five-dimensional space is assumed to be a fiber bundle as in the usual description of a gauge theory and not a more general manifold. Properly taking this into account allows one to use a Lagrangian density for the scalar field which includes charge quantization but not the unphysical superheavy masses found by other authors. A natural, satisfactory explanation of why charge is quantized results

Scattering states of the Klein-Gordon equation with Coulomb-like scalar plus vector potentials in arbitrary dimension

International Nuclear Information System (INIS)

Chen Changyuan; Sun Dongsheng; Lu Falin

2004-01-01

Properties of scattering states of the Klein-Gordon equation with Coulomb-like scalar plus vector potentials are investigated in an arbitrary dimension. Exact results of normalized wave functions of scattering states in the 'k/2π scale' and formula of phase shifts are presented

Geometry of Kaluza-Klein theory. II. Field equations

International Nuclear Information System (INIS)

Maia, M.D.

1985-01-01

In the preceding paper a geometric formulation of Kaluza-Klein theory was presented with the basic assumption that the space-time is locally and isometrically embedded in the high-dimensional space which emerged at the big bang. In the present note the Gauss-Codazzi-Ricci equations which are the integrability equations for the embedding are interpreted as the dynamical equations for a low-energy observer. The second quadratic form which results from the embedding is interpreted as a fundamental spin-two massless field. The dynamics for an observer with high-energy probes is described as usual by the Einstein-Hilbert action defined in the high-dimensional space and dimensionally reduced by integration over the internal space. The behavior of fermion masses under different gravitational field strengths is implemented by use of the mass operator defined with the second-order Casimir operator of the embedding symmetry group

Towers and ladders: Infinite parameter symmetries in Kaluza-Klein theories

International Nuclear Information System (INIS)

Aulakh, C.S.

1984-05-01

We introduce a class of infinite dimensional algebras with a 'generalized loop structure' by considering the global symmetries of the four dimensional Lagrangian obtained by compactifying general relativity coupled to Yang-Mills in six dimensions down to M 4 xS 2 . The generalization to arbitrary dimensions is then obvious. We show by explicit construction that such algebras possess an infinite number of finite sub-algebras. Among which, for the six dimensional case, is so(1,3) realized on S 2 with vanishing Casimir invariants. This so(1,3) may be interpreted, in accord with a previous conjecture of Salam and Strathdee [Ann. Phys. 141, 316(1982)], as the 'ladder' symmetry for the Kaluza-Klein towers. (author)

Chern-Simons topological Lagrangians in odd dimensions and their Kaluza-Klein reduction

International Nuclear Information System (INIS)

Wu, Y.

1984-01-01

Clarifying the behavior of generic Chern-Simons secondary invariants under infinitesimal variation and finite gauge transformation, it is proved that they are eligible to be a candidate term in the Lagrangian in odd dimensions (2k-1 for gauge theories and 4k-1 for gravity). The coefficients in front of these terms may be quantized because of topological reasons. As a possible application, the dimensional reduction of such actions in Kaluza-Klein theory is discussed. The difficulty in defining the Chern-Simons action for topologically nontrivial field configurations is pointed out and resolved

Stationary solutions of the Maxwell-Dirac and the Klein-Gordon-Dirac equations

International Nuclear Information System (INIS)

Esteban, M.J.; Georgiev, V.; Sere, E.

1995-01-01

The Maxwell-Dirac system describes the interaction of an electron with its own electromagnetic field. We prove the existence of soliton-like solutions of Maxwell-Dirac in (3+1)-Minkowski space-time. The solutions obtained are regular, stationary in time, and localized in space. They are found by a variational method, as critical points of an energy functional. This functional is strongly indefinite and presents a lack of compactness. We also find soliton-like solutions for the Klein-Gordon-Dirac system, arising in the Yukawa model. (author). 32 refs

Age, sex and social influences on adult survival in the cooperatively breeding Karoo Scrub-robin

Science.gov (United States)

Lloyd, Penn; Martin, Thomas E.; Taylor, Andrew; Braae, Anne; Altwegg, Res

2016-01-01

Among cooperatively breeding species, helpers are hypothesised to increase the survival of breeders by reducing breeder workload in offspring care and increased group vigilance against predators. Furthermore, parental nepotism or other benefits of group living may provide a survival benefit to young that delay dispersal to help. We tested these hypotheses in the Karoo Scrub-robin (Cercotrichas coryphaeus), a long-lived, and facultative cooperatively breeding species in which male helpers make substantial contributions to the care of young. We found that annual breeder survival in the presence of helpers did not differ detectably from breeders without helpers or breeders that lost helpers. Furthermore, helpers did not gain a survival benefit from deferred breeding; apparent survival did not differ detectably between male helpers and male breeders followed from one year old. These results are consistent with other studies suggesting a lack of adult survival benefits among species where breeders do not substantially reduce workloads when helpers are present. They are also consistent with the hypothesis that males that delay dispersal make the ‘best of a bad job’ by helping on their natal territory to gain indirect fitness benefits when they are unable to obtain a territory vacancy nearby.

Post-breeding migration routes of marine turtles from Bonaire and Klein Bonaire, Caribbean Netherlands

OpenAIRE

Becking, L.E.; Christianen, M.J.A.; Nava, M.I.; Miller, N.; Willis, S.; Dam, Van, R.P.

2016-01-01

The management of small rookeries is key to conserving the regional genetic diversity of marine turtle populations and requires knowledge on population connectivity between breeding and foraging areas. To elucidate the geographic scope of the populations of marine turtles breeding at Bonaire and Klein Bonaire (Caribbean Netherlands) we examined the post-breeding migratory behavior of 5 female loggerheads Caretta caretta, 4 female green turtles Chelonia mydas, and 2 male and 13 female hawksbil...

Schwinger pair creation of Kaluza-Klein particles: Pair creation without tunneling

International Nuclear Information System (INIS)

Friedmann, Tamar; Verlinde, Herman

2005-01-01

We study Schwinger pair creation of charged Kaluza-Klein (KK) particles from a static KK electric field. We find that the gravitational backreaction of the electric field on the geometry--which is incorporated via the electric KK-Melvin solution--prevents the electrostatic potential from overcoming the rest mass of the KK particles, thus impeding the tunneling mechanism which is often thought of as responsible for the pair creation. However, we find that pair creation still occurs with a finite rate formally similar to the classic Schwinger result, but via an apparently different mechanism, involving a combination of the Unruh effect and vacuum polarization due to the E-field

Recharge quantification with radiocarbon: Independent corroboration in three Karoo aquifer studies in Botswana

International Nuclear Information System (INIS)

Verhagen, B.Th.; Bredenkamp, D.B.; Janse van Rensburg, H.; Farr, J.L.

1999-01-01

Environmental isotope data from a 'snapshot' sampling hold out the promise of producing acceptable estimates of ground water recharge for resource management purposes. In three major ground water developments in Botswana, estimates of recharge to the Karoo aquifers in the Kalahari, were based on residence times derived from radiocarbon data. In the assessment, three factors needed to be considered: 1) the model leading to acceptable values of residence times 2) the initial, or recharge, radiocarbon value and 3) appropriate values of aquifer porosity. In the three studies, porosity had been measured on numerous drill cores obtained from the principal fractured sandstone aquifers. The resulting isotope-based recharge values correspond reasonably with independent recharge assessments using the equal volume method to analyse long-term rest level observations in two cases; in the third, recharge was independently assessed on the basis of chloride balance in both unsaturated and saturated zones. It is concluded that a) the isotope snapshot approach can give acceptable values for recharge in the development of ground water resources, providing rational management information early in the life of a ground water supply scheme; b) the exponential model and an initial radiocarbon values of 85% atmospheric are realistic in this environment and c) the total porosity appears to be the appropriate parameter in the calculation of recharge. This also provides an insight into the behaviour of the aquifers. (author)

Geometry of Kaluza-Klein theory. I. Basic setting

International Nuclear Information System (INIS)

Maia, M.D.

1985-01-01

Kaluza-Klein space theory is derived from the hypothesis that the four-dimensional space-time is locally and isometrically embedded in a high-dimensional space which presumably originated at the big bang. For mathematical simplicity the high-dimensional space is taken to be a flat, Minkowski space with 14 dimensions assumed to be the ground state of the theory. The resulting metric is more general than the usual zero-mode metric ansatz but it reduces to the latter in the low-energy sector of the theory. The compactification of the internal space results from the existence of the second quadratic form of the embedded V 4 . A simple model of spherical compact space is considered as a working example, where the spontaneous compactification is a hyperbolic function of the strength of the gravitational field. The symmetry group of the embedding is a combined symmetry which breaks into P 4 x SO(10) in the flat limit of the space-time

Codes on the Klein quartic, ideals, and decoding

DEFF Research Database (Denmark)

Hansen, Johan P.

1987-01-01

descriptions as left ideals in the group-algebra GF(2^{3})[G]. This description allows for easy decoding. For instance, in the case of the single error correcting code of length21and dimension16with minimal distance3. decoding is obtained by multiplication with an idempotent in the group algebra.......A sequence of codes with particular symmetries and with large rates compared to their minimal distances is constructed over the field GF(2^{3}). In the sequence there is, for instance, a code of length 21 and dimension10with minimal distance9, and a code of length21and dimension16with minimal...... distance3. The codes are constructed from algebraic geometry using the dictionary between coding theory and algebraic curves over finite fields established by Goppa. The curve used in the present work is the Klein quartic. This curve has the maximal number of rational points over GF(2^{3})allowed by Serre...

The fissioning universe: Topological inflation and Kaluza-Klein cosmologies

International Nuclear Information System (INIS)

Kaku, Michio; Lykken, J.

1986-01-01

We propose a Kaluza-Klein cosmology by reversing the usual scenario: instead of starting with a flat 4+N dimensional universe in which N of the dimensions curl up into a compact manifold, we start with a compact 3+N dimensional manifold in which 3 of the dimensions are allowed to peel off and expand into the known universe. We reverse the usual ''spontaneous compactification'' scenario begin with a closed manifold Msup(3+N) which undergoes ''spontaneous fissioning'' into a product manifold M 3 xMsup(N). Remarkably, the 3-dimensional universe M 3 can undergo a rapid de Sitter expansion large enough to solve the horizon and flatness problem. We call this ''topological inflation'', which we propose as an alternative to the usual GUT inflation. The inflationary phase automatically terminates into a big bang phase. (orig.)

Vegetation geographical patterns as a key to the past, with emphasis on the dry vegetation types of South Africa

Directory of Open Access Journals (Sweden)

M. J. A. Werger

1983-11-01

Full Text Available Southern Africa is characterized by a highly diversified vegetational cover with extremes as contrasting as desert, tropical forest, alpine grassland, or mediterranean type scrub, and many other types in between. This vegetational pattern is strongly correlated to the climatological pattern. It is therefore likely that past changes in climate can still be partly traced in the vegetational pattern, particularly in geographical anomalies, and that study of these patterns provides complementary evidence to palynological research. The following anomalies in the vegetational pattern are briefly discussed: 1. island-wise occurrence of Afro-montane vegetation on mesic, sheltered sites in the southern Sudano- Zambezian Region, in particular in the Highveld grassland/False Karoo transition area; 2. similar westward occurrence of Sudano-Zambezian scrub patches in the Karoo-Namib Region near the Orange/Vaal confluence; 3. scattered occurrence of Sudano-Zambezian woody species in a matrix of Karoo-Namib vegetation in the marginal Karoo-Namib Region; 4. island-wise occurrence of frost-tolerant, dry, karroid dwarf shrub vegetation of predominantly C,-plants on isolated peaks in the winter rainfall area of Namaqualand; 5. peculiar patchy distribution of some succulents in wide areas of climatically rather homogeneous, succulent dwarf shrub vegetation of predominantly CAM-plants in the escarpment area of Namaqualand. a pattern reminiscent of that in many Cape fynbos species. Interpretation of these patterns logically leads to the conclusion that these result from a previously wetter, a previously cooler, or a previously wetter and cooler climate, respectively, over the parts of southern Africa under discussion. This conclusion is compared with published palynological views.

Lacan leitor de Melanie Klein: O caso Dick em questão

OpenAIRE

Lucero, Ariana; Vorcaro, Angela Maria Resende

2017-01-01

RESUMO - O artigo apresenta a leitura que Jacques Lacan faz do caso Dick, de Melanie Klein. Para tanto, a discussão com o flósofo Jean Hyppolite é retomada com o objetivo de explicitarmos como os mecanismos de Ausstossung [expulsão], Verneinung [negação] e Bejahung [afrmação], descritos por Freud em 1925, podem contribuir para a compreensão da constituição psíquicasob uma perspectiva lacaniana. Em seguida, expomos o caso, tanto para apreendermos clinicamente o que foi exposto na teoria, quant...

Well-posedness for the Cauchy problem of the Klein-Gordon-Zakharov system in 2D

OpenAIRE

Kinoshita, Shinya

2016-01-01

This paper is concerned with the Cauchy problem of $2$D Klein-Gordon-Zakharov system with very low regularity initial data. We prove the bilinear estimates which are crucial to get the local in time well-posedness. The estimates are established by the Fourier restriction norm method. We utilize the bilinear Strichartz estimates and the nonlinear version of the classical Loomis-Whitney inequality which was applied to Zakharov system.

Of towers and ladders: Infinite parameter symmetries in Kaluza-Klein theories

International Nuclear Information System (INIS)

Aulakh, C.S.

1984-01-01

We introduce a class of infinite dimensional algebras with a 'generalized loop structure' by considering the global symmetries of the four-dimensional lagrangian obtained by compactifying general relativity coupled to Yang-Mills in six-dimensions down to M 4 x S 2 . The generalization to arbitrary dimensions is then obvious. We show by explicit construction that such algebras possess an infinite number of finite sub-algebras among which, for the six-dimensional case, is so (1, 3), realized on S 2 with vanishing Casimir invariants. This so (1, 3) may be interpreted, in accordance with a previous conjecture of Salam and Strathdee, as the 'ladder' symmetry for the Kaluza-Klein towers. (orig.)

Book Review: The Shock Doctrine: The Rise of Disaster Capitalism written by Naomi Klein

OpenAIRE

Looney, Robert

2007-01-01

Book review by Dr. Robert Looney of the book The Shock Doctrine: The Rise of Disaster Capitalism written by Naomi Klein. By pure chance, two significant books on capitalism were published within weeks of one another in the early fall of 2007. The first (The Age of Turbulence: Adventures in a New World), by the consummate insider, Alan Greenspan, examiines the inner workings of the capitalist system from the perspective of one who was perhaps as responsible as anyone for its spectacular su...

Three-dimensional Einstein-Klein-Gordon system in characteristic numerical relativity

International Nuclear Information System (INIS)

Barreto, W.; Silva, A. da; Lehner, L.; Gomez, R.; Rosales, L.; Winicour, J.

2005-01-01

We incorporate a massless scalar field into a three-dimensional code for the characteristic evolution of the gravitational field. The extended three-dimensional code for the Einstein-Klein-Gordon system is calibrated to be second-order convergent. It provides an accurate calculation of the gravitational and scalar radiation at infinity. As an application, we simulate the fully nonlinear evolution of an asymmetric scalar pulse of ingoing radiation propagating toward an interior Schwarzschild black hole and compute the backscattered scalar and gravitational outgoing radiation patterns. The amplitudes of the scalar and gravitational outgoing radiation modes exhibit the predicted power law scaling with respect to the amplitude of the initial data. For the scattering of an axisymmetric scalar field, the final ring down matches the complex frequency calculated perturbatively for the l=2 quasinormal mode

Dew formation and activity of biological crusts

NARCIS (Netherlands)

Veste, M.; Heusinkveld, B.G.; Berkowicz, S.M.; Breckle, S.W.; Littmann, T.; Jacobs, A.F.G.

2008-01-01

Biological soil crusts are prominent in many drylands and can be found in diverse parts of the globe including the Atacama desert, Chile, the Namib desert, Namibia, the Succulent-Karoo desert, South Africa, and the Negev desert, Israel. Because precipitation can be negligible in deserts ¿ the

Genetic programming applied to RFI mitigation in radio astronomy

Science.gov (United States)

Staats, K.

2016-12-01

Genetic Programming is a type of machine learning that employs a stochastic search of a solutions space, genetic operators, a fitness function, and multiple generations of evolved programs to resolve a user-defined task, such as the classification of data. At the time of this research, the application of machine learning to radio astronomy was relatively new, with a limited number of publications on the subject. Genetic Programming had never been applied, and as such, was a novel approach to this challenging arena. Foundational to this body of research, the application Karoo GP was developed in the programming language Python following the fundamentals of tree-based Genetic Programming described in "A Field Guide to Genetic Programming" by Poli, et al. Karoo GP was tasked with the classification of data points as signal or radio frequency interference (RFI) generated by instruments and machinery which makes challenging astronomers' ability to discern the desired targets. The training data was derived from the output of an observation run of the KAT-7 radio telescope array built by the South African Square Kilometre Array (SKA-SA). Karoo GP, kNN, and SVM were comparatively employed, the outcome of which provided noteworthy correlations between input parameters, the complexity of the evolved hypotheses, and performance of raw data versus engineered features. This dissertation includes description of novel approaches to GP, such as upper and lower limits to the size of syntax trees, an auto-scaling multiclass classifier, and a Numpy array element manager. In addition to the research conducted at the SKA-SA, it is described how Karoo GP was applied to fine-tuning parameters of a weather prediction model at the South African Astronomical Observatory (SAAO), to glitch classification at the Laser Interferometer Gravitational-wave Observatory (LIGO), and to astro-particle physics at The Ohio State University.

Mode solutions for a Klein-Gordon field in anti-de Sitter spacetime with dynamical boundary conditions of Wentzell type

Science.gov (United States)

Dappiaggi, Claudio; Ferreira, Hugo R. C.; Juárez-Aubry, Benito A.

2018-04-01

We study a real, massive Klein-Gordon field in the Poincaré fundamental domain of the (d +1 )-dimensional anti-de Sitter (AdS) spacetime, subject to a particular choice of dynamical boundary conditions of generalized Wentzell type, whereby the boundary data solves a nonhomogeneous, boundary Klein-Gordon equation, with the source term fixed by the normal derivative of the scalar field at the boundary. This naturally defines a field in the conformal boundary of the Poincaré fundamental domain of AdS. We completely solve the equations for the bulk and boundary fields and investigate the existence of bound state solutions, motivated by the analogous problem with Robin boundary conditions, which are recovered as a limiting case. Finally, we argue that both Robin and generalized Wentzell boundary conditions are distinguished in the sense that they are invariant under the action of the isometry group of the AdS conformal boundary, a condition which ensures in addition that the total flux of energy across the boundary vanishes.

Melanie Klein in Buenos Aires: beginnings and developments.

Science.gov (United States)

Etchegoyen, R Horacio; Zysman, Samuel

2005-06-01

In the first decades of the 20th century, Freud was known and quoted in Latin America by an elite of enlightened minds. In the 1940s a convergence took place in Buenos Aires of European exiles with local pioneers, and thus the Argentine Psychoanalytical Association was founded in 1942. Since then psychoanalysis has grown steadily and has spread into hospitals and universities, influencing culture at large. The socioeconomic situation of that time permitted this phenomenon to develop, to the astonishment of observers. In this paper the authors study the strong influence of Kleinian thought during the first 30 years of this development. The original works of local thinkers constitute the intellectual capital that sustains the idea of an 'Argentine psychoanalytic school'. During the 1970s, both society and psychoanalysis endured deep and complex changes. Lacan's teachings gained support and Klein's influence began to decline. At present the Buenos Aires Kleinians keep working, while their relationship with Lacanians and other schools is calmer. Respectful discussions became thus possible, oriented to strictly scientific differences.

A Study of the Cold Gas and Stellar Populations of the Antlia Cluster with KAT-7 and WISE

NARCIS (Netherlands)

Hess, Kelley; Carignan, C.; Jarrett, T.; Goedhart, S.; Passmoor, S. S.; Wilcots, E. M.

We present neutral hydrogen (HI) observations of the Antlia Galaxy Cluster from the Karoo Array Telescope (KAT-7), a MeerKAT/SKA pathfinder array in South Africa, and describe some of the data reduction challenges overcome by the science commissioning team. Antlia is the third most nearby, massive

Author Details

African Journals Online (AJOL)

Jenkins, LS. Vol 104, No 11 (2014) - Articles Appropriateness of computed tomography and magnetic resonance imaging scans in the Eden and Central Karoo districts of the Western Cape Province, South Africa Abstract PDF. ISSN: 0256-95749. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

The use of social Stegodyphus spider retreats as nest-lining by pale ...

African Journals Online (AJOL)

The pale chanting-goshawk (Melierax canorus) incorporates silk nests (hereafter 'retreats') of the social spider Stegodyphus dumicola (Araneae: Eresidae) in the construction of the nest-lining of their own nests. This study investigates whether pale chanting-goshawks in the Little Karoo, South Africa, show a preference for ...

Moving discrete breathers in a Klein-Gordon chain with an impurity

International Nuclear Information System (INIS)

Cuevas, J; Palmero, F; Archilla, J F R; Romero, F R

2002-01-01

We analyse the influence of an impurity in the evolution of moving discrete breathers in a Klein-Gordon chain with non-weak nonlinearity. Three different types of behaviour can be observed when moving breathers interact with the impurity: they pass through the impurity continuing their direction of movement; they are reflected by the impurity; they are trapped by the impurity, giving rise to chaotic breathers, as their Fourier power spectra show. Resonance with a breather centred at the impurity site is conjectured to be a necessary condition for the appearance of the trapping phenomenon. This paper establishes a difference between the resonance condition of the non-weak nonlinearity approach and the resonance condition with the linear impurity mode in the case of weak nonlinearity

Reflections on Klein's radical notion of phantasy and its implications for analytic practice.

Science.gov (United States)

Blass, Rachel B

2017-06-01

Analysts may incorporate many of Melanie Klein's important contributions (e.g., on preoedipal dynamics, envy, and projective identification) without transforming their basic analytic approach. In this paper I argue that adopting the Kleinian notion of unconscious phantasy is transformative. While it is grounded in Freud's thinking and draws out something essential to his work, this notion of phantasy introduces a radical change that defines Kleinian thinking and practice and significantly impacts the analyst's basic clinical approach. This impact and its technical implications in the analytic situation are illustrated and discussed. Copyright © 2017 Institute of Psychoanalysis.

Simultaneous analysis of 70 pesticides using HPlc/MS/MS: a comparison of the multiresidue method of Klein and Alder and the QuEChERS method.

Science.gov (United States)

Riedel, Melanie; Speer, Karl; Stuke, Sven; Schmeer, Karl

2010-01-01

Since 2003, two new multipesticide residue methods for screening crops for a large number of pesticides, developed by Klein and Alder and Anastassiades et al. (Quick, Easy, Cheap, Effective, Rugged, and Safe; QuEChERS), have been published. Our intention was to compare these two important methods on the basis of their extraction efficiency, reproducibility, ruggedness, ease of use, and speed. In total, 70 pesticides belonging to numerous different substance classes were analyzed at two concentration levels by applying both methods, using five different representative matrixes. In the case of the QuEChERS method, the results of the three sample preparation steps (crude extract, extract after SPE, and extract after SPE and acidification) were compared with each other and with the results obtained with the Klein and Alder method. The extraction efficiencies of the QuEChERS method were far higher, and the sample preparation was much quicker when the last two steps were omitted. In most cases, the extraction efficiencies after the first step were approximately 100%. With extraction efficiencies of mostly less than 70%, the Klein and Alder method did not compare favorably. Some analytes caused problems during evaluation, mostly due to matrix influences.

Approximate Solution of Nonlinear Klein-Gordon Equation Using Sobolev Gradients

Directory of Open Access Journals (Sweden)

Nauman Raza

2016-01-01

Full Text Available The nonlinear Klein-Gordon equation (KGE models many nonlinear phenomena. In this paper, we propose a scheme for numerical approximation of solutions of the one-dimensional nonlinear KGE. A common approach to find a solution of a nonlinear system is to first linearize the equations by successive substitution or the Newton iteration method and then solve a linear least squares problem. Here, we show that it can be advantageous to form a sum of squared residuals of the nonlinear problem and then find a zero of the gradient. Our scheme is based on the Sobolev gradient method for solving a nonlinear least square problem directly. The numerical results are compared with Lattice Boltzmann Method (LBM. The L2, L∞, and Root-Mean-Square (RMS values indicate better accuracy of the proposed method with less computational effort.

Statistical Entropy of the Kaluza－Klein Black Hole from the Horizon Conformal Field Theory

Institute of Scientific and Technical Information of China (English)

JING Ji-Liang; YAN Mu-Lin

2001-01-01

The statistical entropy of the Kaluza-Klein black hole is studied by counting the black hole states which form an algebra of diffeomorphism at Killing horizon with a central charge. It is shown that the entropy yielded by the standard Cardy formula agrees with the Bekenstein-Hawking entropy only if we take period T of function u as the periodicity of the Euclidean black hole. On the other hand, the first-order quantum correction to the entropy is proportional to the logarithm of the Bekenstein-Hawking entropy with a factor -1/2.

Superstatistics of the Klein-Gordon equation in deformed formalism for modified Dirac delta distribution

Science.gov (United States)

Sargolzaeipor, S.; Hassanabadi, H.; Chung, W. S.

2018-04-01

The Klein-Gordon equation is extended in the presence of an Aharonov-Bohm magnetic field for the Cornell potential and the corresponding wave functions as well as the spectra are obtained. After introducing the superstatistics in the statistical mechanics, we first derived the effective Boltzmann factor in the deformed formalism with modified Dirac delta distribution. We then use the concepts of the superstatistics to calculate the thermodynamics properties of the system. The well-known results are recovered by the vanishing of deformation parameter and some graphs are plotted for the clarity of our results.

Quantum cybernetics: a new perspective for Nelson's stochastic theory, nonlocality, and the Klein-Gordon equation

Science.gov (United States)

Grössing, Gerhard

2002-04-01

The Klein-Gordon equation is shown to be equivalent to coupled partial differential equations for a sub-quantum Brownian movement of a “particle”, which is both passively affected by, and actively affecting, a diffusion process of its generally nonlocal environment. This indicates circularly causal, or “cybernetic”, relationships between “particles” and their surroundings. Moreover, in the relativistic domain, the original stochastic theory of Nelson is shown to hold as a limiting case only, i.e., for a vanishing quantum potential.

Extra force and extra mass from non-compact Kaluza-Klein theory in a cosmological model

International Nuclear Information System (INIS)

MadrizAguilar, J.E.; Bellini, M.

2005-01-01

Using the Hamilton-Jacobi formalism, we study extra force and extra mass in a recently introduced non-compact Kaluza-Klein cosmological model. We examine the inertial 4D mass m 0 of the inflaton field on a 4D FRW bulk in two examples. We find that m 0 has a geometrical origin and antigravitational effects on a non-inertial 4D bulk should be a consequence of the motion of the fifth coordinate with respect to the 4D bulk. (orig.)

Author Details

African Journals Online (AJOL)

Rahlao, Sebataolo. Vol 33, No 2 (2016) - Articles Vegetation dynamics after experimental fire disturbance in the arid Succulent Karoo, South Africa Abstract. ISSN: 1022-0119. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

Physical impact of grazing by sheep on the dynamics of Nama ...

African Journals Online (AJOL)

UFS

Physical impact of sheep grazing on arid Karoo subshrub/grass rangeland,. South Africa ... sustainability of rangeland resources, soil and vegetation responses to various grazing systems (Teague &. Dowhower .... The only significant decrease (F3,4 = 18.14, P <0.01) in basal cover of the total herbaceous layer for the 1995 ...

Precambrian-Cambrian provenance of Matinde Formation, Karoo Supergroup, northwestern Mozambique, constrained from detrital zircon U-Pb age and Lu-Hf isotope data

Science.gov (United States)

Bicca, Marcos Müller; Jelinek, Andrea Ritter; Philipp, Ruy Paulo; de Carvalho Lana, Cristiano; Alkmim, Ana Ramalho

2018-02-01

The Permian-Triassic time interval was a period of high sedimentation rates in the intracontinental Karoo rift basin of northwestern Mozambique, reflecting high exhumation rates in the surrounding high ground Precambrian-Cambrian basement and juxtaposed nappes. U-Pb LA-MC-ICPMS dating and Lu-Hf isotopic analysis of detrital zircons from the Late Permian-Early Triassic Matinde Formation of the Karoo Supergroup is used as a reliable proxy to map denudation patterns of source regions. Data allow discrimination of U-Pb age populations of ca. 1250-900 Ma, a secondary population between ca. 900-700 and a major contribution of ages around ca. 700-490 Ma. Zircon grains of the Mesoproterozoic age population present Mesoproterozoic (1000-1500 Ma) to Paleoproterozoic (1800-2300 Ma) Hf TDM ages, with positive (0 to +11) and negative εHf values (-3 to -15), respectively. The younger U-Pb age population also presents two different groups of zircon grains according to Lu-Hf isotopes. The first group comprise Paleoproterozoic (1800-2300 Ma) ages, with highly negative εHf values, between -10 and -22, and the second group exhibits Mesoproterozoic ages (1200-1500 Ma), with increased juvenile εHf values (ca. 0 to -5). These Hf isotopes reinforce the presence of unexposed ancient crust in this region. The oldest U-Pb age population resembles the late stages of Grenville Orogeny and the Rodinia Supercontinent geotectonic activity mostly represented by magmatic rocks, which are widely present in the basement of northern Mozambique. The juvenile Hf-isotope signature with an older age component is associated to rocks generated from subduction processes with crust assimilation by continental arcs, which we correlate to rocks of the Nampula Complex, south and east of the Moatize-Minjova Basin. The U-Pb ages between 900 and 700 Ma were correlated to the calc-alkaline magmatism registered in the Guro Suite, related to the breakup phase of Rodinia, and mark the western limit of the Moatize

A graphene Zener-Klein transistor cooled by a hyperbolic substrate

Science.gov (United States)

Yang, Wei; Berthou, Simon; Lu, Xiaobo; Wilmart, Quentin; Denis, Anne; Rosticher, Michael; Taniguchi, Takashi; Watanabe, Kenji; Fève, Gwendal; Berroir, Jean-Marc; Zhang, Guangyu; Voisin, Christophe; Baudin, Emmanuel; Plaçais, Bernard

2018-01-01

The engineering of cooling mechanisms is a bottleneck in nanoelectronics. Thermal exchanges in diffusive graphene are mostly driven by defect-assisted acoustic phonon scattering, but the case of high-mobility graphene on hexagonal boron nitride (hBN) is radically different, with a prominent contribution of remote phonons from the substrate. Bilayer graphene on a hBN transistor with a local gate is driven in a regime where almost perfect current saturation is achieved by compensation of the decrease in the carrier density and Zener-Klein tunnelling (ZKT) at high bias. Using noise thermometry, we show that the ZKT triggers a new cooling pathway due to the emission of hyperbolic phonon polaritons in hBN by out-of-equilibrium electron-hole pairs beyond the super-Planckian regime. The combination of ZKT transport and hyperbolic phonon polariton cooling renders graphene on BN transistors a valuable nanotechnology for power devices and RF electronics.

Exact Solution of Klein-Gordon and Dirac Equations with Snyder-de Sitter Algebra

Science.gov (United States)

Merad, M.; Hadj Moussa, M.

2018-01-01

In this paper, we present the exact solution of the (1+1)-dimensional relativistic Klein-Gordon and Dirac equations with linear vector and scalar potentials in the framework of deformed Snyder-de Sitter model. We introduce some changes of variables, we show that a one-dimensional linear potential for the relativistic system in a space deformed can be equivalent to the trigonometric Rosen-Morse potential in a regular space. In both cases, we determine explicitly the energy eigenvalues and their corresponding eigenfunctions expressed in terms of Romonovski polynomials. The limiting cases are analyzed for α 1 and α 2 → 0 and are compared with those of literature.

Author Details

African Journals Online (AJOL)

van der Merwe, Helga. Vol 33, No 2 (2016) - Articles Vegetation dynamics after experimental fire disturbance in the arid Succulent Karoo, South Africa Abstract. ISSN: 1022-0119. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

Distribution and protection of endemic or threatened rodents ...

African Journals Online (AJOL)

highest in the south-western parts of the country, and hotspots of endemism cOincide with those of species rich- ness. However, Red ... species richness hotspot in the Succulent Karoo contains no existing reserves, whereas all Red Data Book spe- ... conserve all aspects of biodiversity, but of historical ad hoc decisions ...

Distribution and protection of endemic or threatened rodents ...

African Journals Online (AJOL)

Species richness of the target species is highest in the south-western parts of the country, and hotspots of endemism coincide with those of species richness. However, Red Data Book species hotspots are confined to the north-eastern parts of the country. One species richness hotspol in the Succulent Karoo contains no ...

Camdeboo-Mountain Zebra National Park Corridor: Opportunities for conservation and socio-economic development

Science.gov (United States)

Matthew Norval

2015-01-01

The Wilderness Foundation, in partnership with South African National Parks has initiated a two year project in the Karoo; The Mountain Zebra-Camdeboo Corridor Project. Through either voluntary Contractual National Park or Protected Environment agreements, the project aims to work with, rather than displace, current conservation-compatible land-use practices such as...

Unstable Mode Solutions to the Klein-Gordon Equation in Kerr-anti-de Sitter Spacetimes

Science.gov (United States)

Dold, Dominic

2017-03-01

For any cosmological constant {Λ = -3/ℓ2 r+2 > |a|ℓ}. We obtain an analogous result for Neumann boundary conditions if {5/4 < α < 9/4}. Moreover, in the Dirichlet case, one can prove that, for any Kerr-AdS spacetime violating the Hawking-Reall bound, there exists an open family of masses {α} such that the corresponding Klein-Gordon equation permits exponentially growing mode solutions. Our result adopts methods of Shlapentokh-Rothman developed in (Commun. Math. Phys. 329:859-891, 2014) and provides the first rigorous construction of a superradiant instability for negative cosmological constant.

The rotating dyonic black holes of Kaluza-Klein theory

International Nuclear Information System (INIS)

Rasheed, D.

1995-01-01

The most general electrically and magnetically charged rotating black hole solutions of 5 dimensional Kaluza-Klein theory are given in an explicit form. Various classical quantities associated with the black holes are derived. In particular, one finds the very surprising result that the gyromagnetic and gyroelectric ratios can become arbitrarily large. The thermodynamic quantities of the black holes are calculated and a Smarr-type formula is obtained leading to a generalized first law of black hole thermodynamics. The properties of the extreme solutions are investigated and it is shown how they naturally separate into two classes. The extreme solutions in one class are found to have two unusual properties: (i) Their event horizons have zero angular velocity and yet they have non-zero ADM angular momentum. (ii) In certain circumstances it is possible to add angular momentum to these extreme solutions without changing the mass or charges and yet still maintain an extreme solution. Regarding the extreme black holes as elementary particles, their stability is discussed and it is found that they are stable provided they have sufficient angular momentum. (orig.)

Quadrupole formula for Kaluza-Klein modes in the braneworld

International Nuclear Information System (INIS)

Kinoshita, Shunichiro; Kudoh, Hideaki; Sendouda, Yuuiti; Sato, Katsuhiko

2005-01-01

The quadrupole formula in four-dimensional Einstein gravity is a useful tool to describe gravitational wave radiation. We derive the quadrupole formula for the Kaluza-Klein (KK) modes in the Randall-Sundrum braneworld model. The quadrupole formula provides a transparent representation of the exterior weak gravitational field induced by localized sources. We find that a general isolated dynamical source gives rise to the 1/r 2 correction to the leading 1/r gravitational field. We apply the formula to an evaluation of the effective energy carried by the KK modes from the viewpoint of an observer on the brane. Contrary to the ordinary gravitational waves (zero mode), the flux of the induced KK modes by the non-spherical part of the quadrupole moment vanishes at infinity and only the spherical part contributes to the flux. Since the effect of the KK modes appears in the linear order of the metric perturbations, the effective energy flux observed on the brane is not always positive, but can become negative depending on the motion of the localized sources

One perspective on the Freud-Klein controversies 1941-45.

Science.gov (United States)

Schafer, R

1994-04-01

Comments on the complex relations obtaining between, on the one hand, tradition, innovations and existential perspective and, on the other, presuppositions about method, evidence and truth are prefaced by a review of the helpful and hindering attitudes and conduct of the three parties to these controversial discussions, the third group being the indigenous ('independent') British group. This group directed the process into productive channels against great odds. The subsequent history of psychoanalysis shows, in addition to increased organisational stability and tolerance in times of crisis, an evolving enrichment and refinement of theory and practice in all three groups. Those following Melanie Klein have developed further their own kind of ego-psychological emphasis, while those following Anna Freud and 'the Viennese' around her have developed a more inclusive theoretical and clinical perspective, one that makes more salient the influence of the very first years of life and early infantile aggression as well as accepting a broadening of the idea of transference to include child analysis. This history supports the view that pluralism in psychoanalysis has been of much benefit.

Global existence and uniform stabilization of a generalized dissipative Klein-Gordon equation type with boundary damping

International Nuclear Information System (INIS)

Zhang Zaiyun; Miao Xiujin; Chen Yuezhong; Liu Zhenhai

2011-01-01

In this paper, we prove the existence, uniqueness, and uniform stability of strong and weak solutions of the nonlinear generalized Klein-Gordon equation (1.1) 1 (see Sec. I) in bounded domains with nonlinear damped boundary conditions given by (1.1) 3 (see Sec. I) with some restrictions on function f(u), h(∇u), g(u t ), and b(x), we prove the existence and uniqueness by means of nonlinear semigroup method and obtain the uniform stabilization by using the multiplier technique.

Author Details

African Journals Online (AJOL)

Hein, Liesel. Vol 33, No 2 (2016) - Articles Vegetation dynamics after experimental fire disturbance in the arid Succulent Karoo, South Africa Abstract. ISSN: 1727-9380. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

Improved recovery from Gulf of Mexico reservoirs. Volume I (of 4): Task 1, conduct research on mud-rich submarine fans. Final report, February 14, 1995--October 13, 1996

Energy Technology Data Exchange (ETDEWEB)

Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.

1997-01-13

The objective for this portion of the research involved conducting field studies and laboratory investigations to develop and refine models for mud-rich submarine fan architectures used by seismic analysis and reservoir engineers. These research aspects have been presented in two papers as follows: (1) Bouma, A.H., {open_quotes}Review of Fine-Grained Submarine Fans and Turbidite Systems{close_quotes}; (2) Kirkova, J.T. and Lorenzo, J.M., {open_quotes}Synthetic Seismic Modeling of Measured Submarine Fans Sections, Case Study of the Tanqua Complex, Karoo, South Africa{close_quotes} The {open_quotes}Review of Fine-Grained Submarine Fans and Turbidite Systems{close_quotes} by Arnold Bouma discusses research targeted toward stimulating an increase in oil and gas recovery by developing new and improved geological understanding. The {open_quotes}Synthetic Seismic Modeling of Measured Submarine Fan Sections, Case Study of the Tanqua Complex, Karoo, South Africa{close_quotes} by J.T. Kirkova and J.M. Lorenso discusses the limitations of verticle resolution and how this affects the interpretation and characterization of submarine fan complexes.

South African Journal of Animal Science - Vol 44, No 1 (2014)

African Journals Online (AJOL)

The Tankwa Karoo National Park feral goat population: A unique genetic resource · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. A Kotzé, JP Grobler, E van Marle-Köster, T Jonker, DL Dalton, 43-48. http://dx.doi.org/10.4314/sajas.v44i1.6 ...

Range expansion of the hadeda ibis Bostrychia hagedash in ...

African Journals Online (AJOL)

The southern African range of the habeda ibis Bostrychia hagedash has expanded from 530 900 km 2 in 1910 to 1 323 300 km2 in 1985. Major range expansions have occurred in the fynbos biome of the south-western Cape, the Karoo, the grasslands of the eastern Cape, the Orange Free State and the Transvaal highveld.

Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

Energy Technology Data Exchange (ETDEWEB)

Deng, Xue-Mei [Chinese Academy of Sciences, Purple Mountain Observatory, Nanjing (China); Xie, Yi [Nanjing University, School of Astronomy and Space Science, Nanjing (China); Shanghai Key Laboratory of Space Navigation and Position Techniques, Shanghai (China); Nanjing University, Ministry of Education, Key Laboratory of Modern Astronomy and Astrophysics, Nanjing (China)

2015-11-15

As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of Cassini to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun. (orig.)

Klein and Lacan meet 21st century schizoid man: fairy stories for the modern era.

Science.gov (United States)

Charles, Marilyn

2014-09-01

Melanie Klein invited us into the phenomenology of the schizoid dilemma through her depictions of the paranoid-schizoid position. By inserting his recursive arrows, Bion extended this conceptualization, showing us the folly of believing that we can ever entirely move beyond the frightening fantasies and realities of social exclusion and isolation. The 21st century has brought, along with the explosion of technology, an expulsion from the social order of many children who have found refuge from isolation and humiliation in the more accessible and less terrifying world of media and technological invention. What may look like narcissism can mask a terrible underlying schizoid failure to enter into the human race. This is the realm of fantasy run amok, where desire becomes alien and alienated such that one is haunted and hunted down by its very possibility. In this universe, conceptualizations from Klein, Bion, and Lacan help us to locate the individual who has become caught in a massive psychic retreat such that there is no subject because there are no objects. To illustrate, I describe my work with a young man who is living in a terrible "zombie zone" where people are not real and therefore are incomprehensible and terribly dangerous. The poignancy of his dilemma is heartbreaking. Perhaps that is one lesson we can still take from our old fairy tales: when one's heart can be broken by another's plight, then comes the possibility of a healing, an entry through that piercing of what had been impenetrable.

Geochemical characteristics of Antarctic magmatism connected with Karoo-Maud and Kerguelen mantle plumes

Science.gov (United States)

Sushchevskaya, Nadezhda; Krymsky, Robert; Belyatsky, Boris; Antonov, Anton; Migdisova, Natalya

2013-04-01

dykes of the Schirmacher Oasis and basalts and dolerites of the Queen Maud Land (180 Ma) are identical in petrology and geochemistry terms and supposedly could be interpreted as the manifestation of the Karoo-Maud plume activity in Antarctica [Sushchevskaya et al., 2012]. The spatial distribution of the dikes indicates the eastward spreading of the plume material from DML to the Schirmacher Oasis within at least 10 Ma (up to ~35 Ma, taking into account the uncertainty of age determination). On the other hand, the considerable duration and multistage character of plume magmatism related to the activity of the Karoo-Maud plume in Antarctica and Africa [Leat et al., 2007; Luttinen et al., 2002] may indicate that the Mesozoic dikes of the oasis correspond to a single stage of plume magmatism. On the basis of obtained isotopic data it has been determined two magmatic melt evolution trends for basalts from: Queen Maud Land - Kerguelen Archipelago - Afanasy Nikitin Rise (Indian Ocean) and Jetty - Schirmacher oasises which mantle sources are quite different. Thus the Jetty - Schirmacher oasises magmatic melt sources are characterized by prevalence of the matter of moderately enriched or primitive chondritic mantle source and lithospheric mantle of Proterozoic ages but the substances of depleted mantle source similar to MORB-type and ancient mantle are absent. New data obtained on Nd, Sr, Pb isotopic and lithophile elements compositions of the alkaline-ultrabasic rocks from the Jetty oasis and Gaussberg volcano completed imagine of the Kerguelen-plume evolution. It has been confirmed unique character of the alkaline lamproiites of the Gaussberg volcano enrichments. Highly radiogenic Sr and Pb isotope ratios of these lamproiites reflect melting of the ancient sublithospheric depleted mantle which was stored from the Archean till nowadays unaffected by metasomatic-enrichment processes. During modern melting of this mantle part there is input of additional substances (crustal fluid

Dirac equation in a de Sitter expansion for massive neutrinos from modern Kaluza-Klein theory

International Nuclear Information System (INIS)

Sánchez, Pablo Alejandro; Anabitarte, Mariano; Bellini, Mauricio

2012-01-01

Using the modern Kaluza-Klein theory of gravity (or the Induced Matter theory), we study the Dirac equation for massive neutrinos on a de Sitter background metric from a 5D Riemann-flat (and hence Ricci-flat) extended de Sitter metric, on which is defined the vacuum for test massless 1/2-spin neutral fields minimally coupled to gravity and free of any other interactions. We obtain that the effective 4D masses of the neutrinos can only take three possible values, which are related to the (static) foliation of the fifth and noncompact extra dimension.

Klein, Debra L. – Yorùbá Bàtá Goes Global

OpenAIRE

Vallier, Gilles-Félix

2012-01-01

Yorùbá Bàtá Goes Global, l’ethnographie de Debra Klein fait la chronique de l’émergence d’un « mouvement culturel yorùbá », une industrie de la culture centrée sur Bàtá, une tradition de danses masquées et rythmes de percussions (egúngún agbégijó). De par sa nature même, le Bàtá yorùbá a trait à la collaboration et l’innovation. Influencé autrefois par l’islam, Bàtá est désormais formalisé par les collaborations entretenues aussi bien entre des percussionnistes locaux, l’État fédéral nigérian...

All the Four-Dimensional Static, Spherically Symmetric Solutions of Abelian Kaluza-Klein Theory

International Nuclear Information System (INIS)

Cvetic, M.; Youm, D.

1995-01-01

We present the explicit form for all the four-dimensional, static, spherically symmetric solutions in (4+n)-d Abelian Kaluza-Klein theory by performing a subset of SO(2,n) transformations corresponding to four SO(1,1) boosts on the Schwarzschild solution, supplemented by SO(n)/SO(n-2) transformations. The solutions are parametrized by the mass M, Taub-NUT charge a, and n electric rvec Q and n magnetic rvec P charges. Nonextreme black holes (with zero Taub-NUT charge) have either the Reissner-Nordstroem or Schwarzschild global space-time. Supersymmetric extreme black holes have a null or naked singularity, while nonsupersymmetric extreme ones have a global space-time of extreme Reissner-Nordstroem black holes. copyright 1995 The American Physical Society

Remarks on a five-dimensional Kaluza-Klein theory of the massive Dirac monopole

International Nuclear Information System (INIS)

Cotaescu, Ion I.

2005-01-01

The Gross-Perry-Sorkin spacetime, formed by the Euclidean Taub-Newman-Unti-Tamburino space with the time trivially added, is the appropriate background of the Dirac magnetic monopole without an explicit mass term. We show that there exists a very simple five-dimensional metric of spacetimes carrying massive magnetic monopoles that is an exact solution of the vacuum Einstein equations. Moreover, the same isometry properties as the original Euclidean Taub-Newman-Unti-Tamburino space are preserved. This leads to an Abelian Kaluza-Klein theory whose metric appears as a combination between the Gross-Perry-Sorkin and Schwarzschild ones. The asymptotic motion of the scalar charged test particles is discussed, now by accounting for the mixing between the gravitational and magnetic effects

Zeta-function regularization approach to finite temperature effects in Kaluza-Klein space-times

International Nuclear Information System (INIS)

Bytsenko, A.A.; Vanzo, L.; Zerbini, S.

1992-01-01

In the framework of heat-kernel approach to zeta-function regularization, in this paper the one-loop effective potential at finite temperature for scalar and spinor fields on Kaluza-Klein space-time of the form M p x M c n , where M p is p-dimensional Minkowski space-time is evaluated. In particular, when the compact manifold is M c n = H n /Γ, the Selberg tracer formula associated with discrete torsion-free group Γ of the n-dimensional Lobachevsky space H n is used. An explicit representation for the thermodynamic potential valid for arbitrary temperature is found. As a result a complete high temperature expansion is presented and the roles of zero modes and topological contributions is discussed

TeV gravity and Kaluza-Klein excitations in e{sup +}e{sup {minus}} and e{sup {minus}}e{sup {minus}} collisions

Energy Technology Data Exchange (ETDEWEB)

Rizzo, T.G.

2000-01-24

The authors review the capability of e{sup +}e{sup {minus}} and e{sup {minus}}e{sup {minus}} colliders to detect the virtual exchange of Kaluza-Klein towers of gravitons within the large extra dimension scenario of Arkani-Hamed, Dimopoulos and Dvali and in the localized gravity model of Randall and Sundrum with non-factorizable geometry.

Clay minerals as palaeoenvironment indicators exemplified on a Karoo sequence from the Bothaville area, South Africa

International Nuclear Information System (INIS)

Buehmann, C.; Buehmann, D.

1990-01-01

The whole-rock and clay mineral composition of 74 samples from a 184 m borehole core from the Ecca Group and Dwyka Formation from the vicinity of Bothaville, 100 km southwest of Johannesburg, South Africa, has been determined by means of X-ray diffractometry. The objective was to establish the salinity and pH of the water of the original environments of deposition. The sediment investigated was subjected to a low degree of diagenesis. Clay mineral associations display characteristic variations while distinctive vertical trends in kaolinite occurrence have been established. Mineralogical trends are ascribed to fundamental changes, which must have existed in the pore fluid composition during deposition (palaeoenvironment setting) which have been maintained through the early stages of diagenesis. Conditions were alkaline-marine during the Dwyka and in the lower section of the Vryheid Formation, as indicated by the dominance of 2:1 layer silicates. From the middle section of the Vryheid Formation the entire brackish water mixing range is recorded mineralogically by kaolinite contents which increase progressively at the cost of 2:1 layer silicates. Acid-freshwater conditions, characterised by the dominance of kaolinite are interpreted for the upper section of the Vryheid Formation. 26 refs., 6 figs., 2 tabs

Relativistic particle in a box: Klein-Gordon versus Dirac equations

Science.gov (United States)

Alberto, Pedro; Das, Saurya; Vagenas, Elias C.

2018-03-01

The problem of a particle in a box is probably the simplest problem in quantum mechanics which allows for significant insight into the nature of quantum systems and thus is a cornerstone in the teaching of quantum mechanics. In relativistic quantum mechanics this problem allows also to highlight the implications of special relativity for quantum physics, namely the effect that spin has on the quantised energy spectra. To illustrate this point, we solve the problem of a spin zero relativistic particle in a one- and three-dimensional box using the Klein-Gordon equation in the Feshbach-Villars formalism. We compare the solutions and the energy spectra obtained with the corresponding ones from the Dirac equation for a spin one-half relativistic particle. We note the similarities and differences, in particular the spin effects in the relativistic energy spectrum. As expected, the non-relativistic limit is the same for both kinds of particles, since, for a particle in a box, the spin contribution to the energy is a relativistic effect.

Contact doping, Klein tunneling, and asymmetry of shot noise in suspended graphene

Science.gov (United States)

Laitinen, Antti; Paraoanu, G. S.; Oksanen, Mika; Craciun, Monica F.; Russo, Saverio; Sonin, Edouard; Hakonen, Pertti

2016-01-01

The inherent asymmetry of the electric transport in graphene is attributed to Klein tunneling across barriers defined by p n interfaces between positively and negatively charged regions. By combining conductance and shot noise experiments, we determine the main characteristics of the tunneling barrier (height and slope) in a high-quality suspended sample with Au/Cr/Au contacts. We observe an asymmetric resistance Rodd=100 -70 Ω across the Dirac point of the suspended graphene at carrier density | nG|=(0.3 -4 ) × 1011cm-2 , while the Fano factor displays a nonmonotonic asymmetry in the range Fodd˜0.03 -0.1. Our findings agree with analytical calculations based on the Dirac equation with a trapezoidal barrier. Comparison between the model and the data yields the barrier height for tunneling, an estimate of the thickness of the p n interface d graphene.

Exact solution of the Klein-Gordon equation for the PT-symmetric generalized Woods-Saxon potential by the Nikiforov-Uvarov method

International Nuclear Information System (INIS)

Ikhdair, S.M.; Sever, R.

2007-01-01

The exact solution of the one-dimensional Klein-Gordon equation of the PT-symmetric generalized Woods-Saxon potential is obtained. The exact energy eigenvalues and wavefunctions are derived analytically by using the Nikiforov and Uvarov method. In addition, the positive and negative exact bound states of the s-states are also investigated for different types of complex generalized Woods-Saxon potentials. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Checklist of the birds of Aruba, Curaçao and Bonaire, South Caribbean

NARCIS (Netherlands)

Prins, T.G.; Reuter, J.H.; Debrot, A.O.; Wattel, J.; Nijman, V.

2009-01-01

We present an updated checklist of the birds of the islands of Aruba, Curaçao and Bonaire, and the islets of Klein Curaçao and Klein Bonaire, southern Caribbean, and compare this with earlier checklists (K.H. Voous, Stud. Fauna Curaçao Carib. Isl. 7: 1-260, 1957; Ardea 53: 205-234, 1965; Birds of

Smooth manifolds for certain dynamical systems and periodic solitons for nonlinear Klein-Gordon equations on R2

International Nuclear Information System (INIS)

Vuillermot, P.A.

1988-01-01

We present and discuss three new theorems concerning the existence of smooth manifolds associated with certain infinite-dimensional dynamical systems defined from nonlinear Klein-Gordon equations of the form u tt (x, t) = u xx (x, t)-g(u(x, t)), where g: R → R is analytic and where (x, t) ε R 2 . In particular, we prove the nonexistence of small amplitude soliton bound state solutions in the classical Φ 4 -theory, a fact recently brought about by the perturbative analysis of Kruskal and Segur [fr

Experimental verification of the relativistic fine-structure term of the Klein-Gordon equation in pionic titanium atoms

International Nuclear Information System (INIS)

Delker, L.; Dugan, G.; Wu, C.S.; Lu, D.C.; Caffrey, A.J.; Cheng, Y.T.; Lee, Y.K.

1979-01-01

A newly designed, large-aperture and high-resolution bent-crystal spectrometer has been used to observe high-intensity sources of pionic x rays. The pionic x-ray source was a target of natural titanium which was placed adjacent to a copper pion-production target in the external beam of the Nevis synchrocyclotron. The energy difference between the 5g → 4f and 5f → 4d transitions in pionic titanium was measured to be 87.6 +- 1.8 eV. Comparison with the prediction of the Klein-Gordon equation is made

EPR & Klein Paradoxes in Complex Hamiltonian Dynamics and Krein Space Quantization

Science.gov (United States)

Payandeh, Farrin

2015-07-01

Negative energy states are applied in Krein space quantization approach to achieve a naturally renormalized theory. For example, this theory by taking the full set of Dirac solutions, could be able to remove the propagator Green function's divergences and automatically without any normal ordering, to vanish the expected value for vacuum state energy. However, since it is a purely mathematical theory, the results are under debate and some efforts are devoted to include more physics in the concept. Whereas Krein quantization is a pure mathematical approach, complex quantum Hamiltonian dynamics is based on strong foundations of Hamilton-Jacobi (H-J) equations and therefore on classical dynamics. Based on complex quantum Hamilton-Jacobi theory, complex spacetime is a natural consequence of including quantum effects in the relativistic mechanics, and is a bridge connecting the causality in special relativity and the non-locality in quantum mechanics, i.e. extending special relativity to the complex domain leads to relativistic quantum mechanics. So that, considering both relativistic and quantum effects, the Klein-Gordon equation could be derived as a special form of the Hamilton-Jacobi equation. Characterizing the complex time involved in an entangled energy state and writing the general form of energy considering quantum potential, two sets of positive and negative energies will be realized. The new states enable us to study the spacetime in a relativistic entangled “space-time” state leading to 12 extra wave functions than the four solutions of Dirac equation for a free particle. Arguing the entanglement of particle and antiparticle leads to a contradiction with experiments. So, in order to correct the results, along with a previous investigation [1], we realize particles and antiparticles as physical entities with positive energy instead of considering antiparticles with negative energy. As an application of modified descriptions for entangled (space

Gauge fields with respect to d = (3+1) in the Kaluza-Klein theories and in the spin-charge-family theory

Energy Technology Data Exchange (ETDEWEB)

Lukman, Dragan; Mankoc Borstnik, Norma Susana [University of Ljubljana, Department of Physics, FMF, Ljubljana (Slovenia)

2017-04-15

It is shown that in the spin-charge-family theory (Mankoc Borstnik in arXiv:1607.01618v2, 2016, Phys Rev D 91:065004. arxiv:1409.7791, 2015, J Mod Phys 6:2244. doi:10.4236/jmp.2015.615230. arXiv: 1409.4981, 2015, J Mod Phys 4:823. doi:10.4236/jmp.2013.46113. arxiv:1312.1542, 2013, arxiv:1409.4981, 2014) as well as in all the Kaluza-Klein like theories (Blagojevic in Gravitation and gauge symmetries, IoP Publishing, Bristol, 2002, An introduction to Kaluza-Klein theories, World Scientific, Singapore, 1983), vielbeins and spin connections manifest in d = (3+1) space equivalent vector gauge fields, when space with d ≥ 5 has a large enough symmetry. The authors demonstrate this equivalence in spaces with the symmetry of the metric tensor in the space out of d = (3+1)-g{sup στ} = η{sup στ} f{sup 2} - for any scalar function f of the coordinates x{sup σ}, where x{sup σ} denotes the coordinates of space out of d = (3+1). Also the connection between vielbeins and scalar gauge fields in d = (3+1) (offering the explanation for the Higgs scalar) is discussed. (orig.)

Optimization of the polarized Klein tunneling currents in a sub-lattice: pseudo-spin filters and latticetronics in graphene ribbons.

Science.gov (United States)

López, Luis I A; Yaro, Simeón Moisés; Champi, A; Ujevic, Sebastian; Mendoza, Michel

2014-02-12

We found that with an increase of the potential barrier applied to metallic graphene ribbons, the Klein tunneling current decreases until it is totally destroyed and the pseudo-spin polarization increases until it reaches its maximum value when the current is zero. This inverse relation disfavors the generation of polarized currents in a sub-lattice. In this work we discuss the pseudo-spin control (polarization and inversion) of the Klein tunneling currents, as well as the optimization of these polarized currents in a sub-lattice, using potential barriers in metallic graphene ribbons. Using density of states maps, conductance results, and pseudo-spin polarization information (all of them as a function of the energy V and width of the barrier L), we found (V, L) intervals in which the polarized currents in a given sub-lattice are maximized. We also built parallel and series configurations with these barriers in order to further optimize the polarized currents. A systematic study of these maps and barrier configurations shows that the parallel configurations are good candidates for optimization of the polarized tunneling currents through the sub-lattice. Furthermore, we discuss the possibility of using an electrostatic potential as (i) a pseudo-spin filter or (ii) a pseudo-spin inversion manipulator, i.e. a possible latticetronic of electronic currents through metallic graphene ribbons. The results of this work can be extended to graphene nanostructures.

Hadamard States for the Klein-Gordon Equation on Lorentzian Manifolds of Bounded Geometry

Science.gov (United States)

Gérard, Christian; Oulghazi, Omar; Wrochna, Michał

2017-06-01

We consider the Klein-Gordon equation on a class of Lorentzian manifolds with Cauchy surface of bounded geometry, which is shown to include examples such as exterior Kerr, Kerr-de Sitter spacetime and the maximal globally hyperbolic extension of the Kerr outer region. In this setup, we give an approximate diagonalization and a microlocal decomposition of the Cauchy evolution using a time-dependent version of the pseudodifferential calculus on Riemannian manifolds of bounded geometry. We apply this result to construct all pure regular Hadamard states (and associated Feynman inverses), where regular refers to the state's two-point function having Cauchy data given by pseudodifferential operators. This allows us to conclude that there is a one-parameter family of elliptic pseudodifferential operators that encodes both the choice of (pure, regular) Hadamard state and the underlying spacetime metric.

La jurisdicción del Tribunal Europeo de Derechos Humanos en casos de extradición. A propósito del caso Klein c. Rusia

Directory of Open Access Journals (Sweden)

Jan Schneider

2010-12-01

Full Text Available Analizamos la decisión del Tribunal Europeo de Derechos Humanos –TEDH– en el caso Klein c. Rusia de un ciudadano israelí requerido en extradición por Colombia para la ejecución de una sentencia por entrenamiento de grupos paramilitares. La decisión es presentada en el marco más amplio de la jurisprudencia del TEDH en casos de extradición desde Estados europeos a terceros Estados donde existe el riesgo de violación de los derechos humanos. Desarrollamos los principios que el TEDH aplica en estos casos y verificamos su aplicación en el caso Klein c. Rusia, tomando en cuenta también la opinión separada de los jueces minoritarios. En las conclusiones presentamos una perspectiva sobre cómo evitar la impunidad de perpetradores de violaciones de derechos humanos que no pueden ser extraditados por razones humanitarias.

Kaluza-Klein gluon + jets associated production at the Large Hadron Collider

CERN Document Server

Iyer, A.M.; Manglani, N.; Sridhar, K.

2016-08-10

The Kaluza-Klein excitations of gluons offer the exciting possibility of probing bulk Randall-Sundrum (RS) models. In these bulk models either a custodial symmetry or a deformation of the metric away from AdS is invoked in order to deal with electroweak precision tests. Addressing both these models, we suggest a new channel in which to study the production of KK-gluons ($g_{KK}$): one where it is produced in association with one or more hard jets. The cross-section for the $g_{KK}+$ jets channel is significant because of several contributing sub-processes. In particular, the 1-jet and the 2-jet associated processes are important because at these orders in QCD the $qg$ and the $gg$ initial states respectively come into play. We have performed a hadron-level simulation of the signal and present strategies to effectively extract the signal from what could potentially be a huge background. We present results for the kinematic reach of the LHC Run-II for different $g_{KK}$ masses in bulk-RS models.

Kaluza-Klein cosmological model in f(R, T) gravity with Λ(T)

Science.gov (United States)

Sahoo, P. K.; Mishra, B.; Tripathy, S. K.

2016-04-01

A class of Kaluza-Klein cosmological models in $f(R,T)$ theory of gravity have been investigated. In the work, we have considered the functional $f(R,T)$ to be in the form $f(R,T)=f(R)+f(T)$ with $f(R)=\\lambda R$ and $f(T)=\\lambda T$. Such a choice of the functional $f(R,T)$ leads to an evolving effective cosmological constant $\\Lambda$ which depends on the stress energy tensor. The source of the matter field is taken to be a perfect cosmic fluid. The exact solutions of the field equations are obtained by considering a constant deceleration parameter which leads two different aspects of the volumetric expansion namely a power law and an exponential volumetric expansion. Keeping an eye on the accelerating nature of the universe in the present epoch, the dynamics and physical behaviour of the models have been discussed. From statefinder diagnostic pair we found that the model with exponential volumetric expansion behaves more like a $\\Lambda$CDM model.

Superconformal symmetry in the Kaluza-Klein spectrum of warped AdS(3)

Energy Technology Data Exchange (ETDEWEB)

Schmude, Johannes; Vasilakis, Orestis [Department of Physics, Universidad de Oviedo, Avda. Calvo Sotelo 18, 33007, Oviedo (Spain)

2016-10-18

We study the Kaluza-Klein spectrum of warped AdS{sub 3} compactifications of type IIB with five-form flux which are dual to N=(0,2) SCFTs in two dimensions. We prove that the spectra of fluctuations of both the spin 2 sector of the graviton and the axio-dilaton are bounded. At the bound the modes have the correct quantum numbers to be chiral primaries and descendants thereof respectively. Moreover, we prove that the same modes give rise to superpartners in the dilatino spectrum. Our results show that a subset of the mesonic chiral ring of the dual SCFT is isomorphic to the first Kohn-Rossi cohomology groups. As an example, we consider the compactification of four-dimensional Y{sup p,q} theories on Riemann surfaces for the case of the universal twist. We conclude by studying fluctuations of the three-form, where we are able to identify Betti multiplets after imposing some mild assumptions.

A geological and hydrogeochemical investigation of the uranium potential of an area between the Orange and Kuruman Rivers, northwestern Cape Province. V.1

International Nuclear Information System (INIS)

Levin, M.

1980-04-01

An extensive geological, hydrological and hydrochemical study was conducted to determine the uranium potential of an area which includes the greater part of the Gordonia District and part of the bordering Kuruman District. The area is situated between 21 and 22 degrees east, the Kuruman River in the north and the Orange River in the south. All berohole information germane to the area, such as Government and private drill records have been studied. As a result of this study maps of the area have been compiled, showing surface and pre-Karoo geology, the pre-Karoo and pre-Kalahari topography and the thickness of the Karoo and post-Karoo cover. Contour maps of water levels were compiled from which a regional east-west flow pattern was deduced, indicating a large groundwater basin which could be divided into four smaller basins. Hydrochemical studies substantiate the inferred flow pattern of the groundwater. Of prime importance in this investigation was the study of the distribution of uranium in the groundwater of the area and its association with the various lithologies encountered. Radiometric borehole logging of all accessible boreholes in the most promising areas delineated by this study confirmed the presence of uranium mineralisation in the depositional basins (in particular the Dwyka Tillite Formation) west of the granite-gneiss ridge. Uranium mineralisation in surficial deposits was also discovered as a result of the reassessment of radiometric airborne data obtained previously. It is concluded that potential economic uranium deposits may exist in the Dwyka Tillite Formation northwest of Upington and in the surficial diatomaceous earth deposits on the farm Rus-en-Vrede [af

Unconscious phantasy as a structural principle and organizer of mental life: The evolution of a concept from Freud to Klein and some of her successors.

Science.gov (United States)

Weiss, Heinz

2017-06-01

Starting with Freud's discovery of unconscious phantasy as a means of accessing his patients' internal world, the author discusses the evolution of the concept in the work of Melanie Klein and some of her successors. Whereas Freud sees phantasy as a wish fulfilling imagination, dominated by primary process functioning and kept apart from reality testing, Klein understands phantasies as a structural function and organizer of mental life. From their very beginnings they involve object relations and gradually evolve from primitive body-near experiences to images and symbolic representations. With her concept of projective identification in particular, Klein anticipates the communicative function of unconscious phantasies. They are at the basis of processes of symbolization, but may also be put into the service of complex defensive operations. The author traces the further evolution of the concept from the contributions of S. Isaacs, the theories of thinking proposed by W.R. Bion and R. Money-Kyrle, Hanna Segal's ideas on symbolization and reparation all the way to the latest approaches by R. Britton, J. Steiner and others, including the understanding of transference and counter-transference as a 'total situation'. Points of contact with Freud are to be found particularly in connection with his concept of 'primal phantasies'. In the author's view, the idea of the transmission and communicative potential of unconscious phantasies enabled these authors to overcome the solipsistic origins of drive theory in favour of a notion in which unconscious phantasies both set down the coordinates of the inner world and form and reflect the matrix of inter-subjective relations. Copyright © 2017 Institute of Psychoanalysis.

Prograding coastal facies associations in the Vryheid formation (Permian) at Effingham quarries near Durban, South Africa

Science.gov (United States)

Tavener-Smith, R.

1982-05-01

This paper describes and interprets a flat-lying, sandstone—siltstone sequence 70 m thick in three disused quarries. The beds comprise the lowest part of the Vryheid Formation (middle Ecca) in the Durban vicinity. The sequence is conveniently divisible into two parts: the Lower Division constitutes a prograding beach barrier association, while the upper one represents a back barrier lagoonal complex. Fourteen sedimentary facies are described and interpreted to represent a range of depositional environments including open water shelf silts, sandy shoreface and littoral deposits, organic-rich muds and peats of lagoonal origin, a tidal inlet, washover fans and a fluvial channel sand. Among the conclusions reached are that the local middle Ecca coastline extended in a northwest to southeast direction and that progradation was towards the southwest; that the coastline was microtidal and that stormy conditions were common with prevalent palaeowinds from the northwest. The absence of invertebrate body fossils in these strata is attributed to penecontemporaneous solution of shelly remains. This is the first time that a coastal sequence has been identified on the southeast margin of the Main Karoo Basin of South Africa

EPR and Klein Paradoxes in Complex Hamiltonian Dynamics and Krein Space Quantization

International Nuclear Information System (INIS)

Payandeh, Farrin

2015-01-01

Negative energy states are applied in Krein space quantization approach to achieve a naturally renormalized theory. For example, this theory by taking the full set of Dirac solutions, could be able to remove the propagator Green function's divergences and automatically without any normal ordering, to vanish the expected value for vacuum state energy. However, since it is a purely mathematical theory, the results are under debate and some efforts are devoted to include more physics in the concept. Whereas Krein quantization is a pure mathematical approach, complex quantum Hamiltonian dynamics is based on strong foundations of Hamilton-Jacobi (H-J) equations and therefore on classical dynamics. Based on complex quantum Hamilton-Jacobi theory, complex spacetime is a natural consequence of including quantum effects in the relativistic mechanics, and is a bridge connecting the causality in special relativity and the non-locality in quantum mechanics, i.e. extending special relativity to the complex domain leads to relativistic quantum mechanics. So that, considering both relativistic and quantum effects, the Klein-Gordon equation could be derived as a special form of the Hamilton-Jacobi equation. Characterizing the complex time involved in an entangled energy state and writing the general form of energy considering quantum potential, two sets of positive and negative energies will be realized. The new states enable us to study the spacetime in a relativistic entangled “space-time” state leading to 12 extra wave functions than the four solutions of Dirac equation for a free particle. Arguing the entanglement of particle and antiparticle leads to a contradiction with experiments. So, in order to correct the results, along with a previous investigation [1], we realize particles and antiparticles as physical entities with positive energy instead of considering antiparticles with negative energy. As an application of modified descriptions for entangled (space

Cosmological bounds on large extra dimensions from nonthermal production of Kaluza-Klein modes

International Nuclear Information System (INIS)

Allahverdi, Rouzbeh; Bird, Chris; Groot Nibbelink, Stefan; Pospelov, Maxim

2004-01-01

The existing cosmological constraints on theories with large extra dimensions rely on the thermal production of the Kaluza-Klein (KK) modes of gravitons and radions in the early Universe. Successful inflation and reheating, as well as baryogenesis, typically requires the existence of a TeV-scale field in the bulk, most notably the inflaton. The nonthermal production of KK modes with masses of order 100 GeV accompanying the inflaton decay sets the lower bounds on the fundamental scale M * . For a 1-TeV inflaton, the late decay of these modes distorts the successful predictions of big bang nucleosynthesis unless M * >35, 13, 7, 5, and 3 TeV for two, three, four, five, and six extra dimensions, respectively. This improves the existing bounds from cosmology on M * for four, five, and six extra dimensions. Even more stringent bounds are derived for a heavier inflaton

Finite temperature Casimir effect for a massless fractional Klein-Gordon field with fractional Neumann conditions

International Nuclear Information System (INIS)

Eab, C. H.; Lim, S. C.; Teo, L. P.

2007-01-01

This paper studies the Casimir effect due to fractional massless Klein-Gordon field confined to parallel plates. A new kind of boundary condition called fractional Neumann condition which involves vanishing fractional derivatives of the field is introduced. The fractional Neumann condition allows the interpolation of Dirichlet and Neumann conditions imposed on the two plates. There exists a transition value in the difference between the orders of the fractional Neumann conditions for which the Casimir force changes from attractive to repulsive. Low and high temperature limits of Casimir energy and pressure are obtained. For sufficiently high temperature, these quantities are dominated by terms independent of the boundary conditions. Finally, validity of the temperature inversion symmetry for various boundary conditions is discussed

Familial Kleine-Levin Syndrome: A Specific Entity?

Science.gov (United States)

Nguyen, Quang Tuan Remy; Groos, Elisabeth; Leclair-Visonneau, Laurène; Monaca-Charley, Christelle; Rico, Tom; Farber, Neal; Mignot, Emmanuel; Arnulf, Isabelle

2016-08-01

Kleine-Levin syndrome (KLS) is a rare, mostly sporadic disorder, characterized by intermittent episodes of hypersomnia plus cognitive and behavior disorders. Although its cause is unknown, multiplex families have been described. We contrasted the clinical and biological features of familial versus sporadic KLS. Two samples of patients with KLS from the United States and France (n = 260) were studied using clinical interviews and human leukocyte antigen (HLA) genotyping. A multiplex family contained two or more first- or second-degree affected relatives (familial cases). Twenty-one patients from 10 multiplex families (siblings: n = 12, including two pairs of monozygotic twins; parent-child: n = 4; cousins: n = 2; uncle-nephews: n = 3) and 239 patients with sporadic KLS were identified, yielding to 4% multiplex families and 8% familial cases. The simplex and multiplex families did not differ for autoimmune, neurological, and psychiatric disorders. Age, sex ratio, ethnicity, HLA typing, karyotyping, disease course, frequency, and duration of KLS episodes did not differ between groups. Episodes were less frequent in familial versus sporadic KLS (2.3 ± 1.8/y versus 3.8 ± 3.7/y, P = 0.004). Menses triggered more frequently KLS onset in the nine girls with familial KLS (relative risk, RR = 4.12, P = 0.03), but not subsequent episodes. Familial cases had less disinhibited speech (RR = 3.44, P = 0.049), less combined hypophagia/hyperphagia (RR = 4.38, P = 0.006), more abrupt termination of episodes (RR = 1.45, P = 0.04) and less postepisode insomnia (RR = 2.16, P = 0.008). There was similar HLA DQB1 distribution in familial versus sporadic cases and no abnormal karyotypes. Familial KLS is mostly present in the same generation, and is clinically similar to but slightly less severe than sporadic KLS. © 2016 Associated Professional Sleep Societies, LLC.

eLEARNING - EINE CHANCE FÜR KLEINE UND MITTLERE UNTERNEHMEN

Directory of Open Access Journals (Sweden)

Ileana Hamburg

2005-12-01

Full Text Available eLearning wird durch seine Flexibilität und Zugänglichkeit als bedeutendes Instrument für die Implementierung lebenslangen Lernens (LLL angesehen. Es kann für kleine und mittelgroße Unternehmen (KMU einen Katalysator des Wandels sein und bietet damit die Chance zur Verbesserung der wirtschaftlichen Leistungsfähigkeit. Darüber hinaus kann eLearning dazu dienen, die Integration von KMU in den europäischen Markt zu fördern. Bis jetzt wird eLearning im Rahmen der beruflichen Aus- und Weiterbildung jedoch nahezu ausschließlich in Großunternehmen genutzt, während es in KMU allenfalls eine marginale Rolle spielt. Im ersten Kapitel dieses Artikels wird auf den Perspektivenwechsel in der beruflichen Aus- und Weiterbildung eingegangen. Im Anschluss daran werden die zentralen Elemente von eLearning vorgestellt (Kap. 2. Die mit eLearning verbundenen Chancen und Herausforderungen für KMU diskutiert (Kap. 3. Abschließend wird auf Erfahrungen mit eLearning in der Praxis am Beispiel von drei EU-finanzierten Projekten eingegangen. Das Hauptaugenmerk liegt dabei auf dem laufenden Projekt ARIEL -Analysing and Reporting the Implementation of Electronic Learning in Europe -, das vom Institut Arbeit und Technik, Gelsenkirchen, (IAT koordiniert wird.

A South African study of consumers' perceptions of food labels and its relevance to their purchasing behaviour / R. Klein

OpenAIRE

Klein, Riana

2005-01-01

BACKGROUND AND MOTIVATION: This study had been motivated by the lack of existing data on South African consumers' perceptions of food labels and its relevance to purchasing behaviour. In order to gather this information it is important to understand consumers and their purchasing behaviour so that these could be translated into food label characteristics to implement consumer-oriented label development (Sijtsema et al., 2002:565). Consumers' purchasing behaviour is influenc...

The sedimentology and uranium mineralisation of the DR-3 deposit, Laingsburg district

International Nuclear Information System (INIS)

Le Roux, J.P.

1982-08-01

As part of its research program in the Karoo, NUCOR carried out a sedimentological investigation of the DR-3 deposit, discovered by JCI. It is located on the farm Drie Vaderlandsche Rietvalleyen, 40 km north of Laingsburg, in an unnamed sandstone package of the Abrahamskraal Formation. The orebody lies in an area affected by southward-dipping monoclines, which possibly originated because of basement faults during subsidence of the Karoo trough. These monoclines may be have locally altered the courses of rivers flowing from the source areas to the south-west. The S1-sandstone which hosts the uranium was probably deposited in a braided river environment of the Donjek type. The vector mean azimuth is towards 075 degrees for S1 and 062 degrees for the studied sequence as a whole, but towards the east there is a marked change in the palaeocurrent direction. On a more regional scale, preliminary investigations indicate the braided river system was at least 5 km wide. Uranium mineralisation on DR-3 is concentrated within a major east-west-trending channel, with the best-developed ore at the junctions of this channel with tributaries from the south. This is probably due to plant material settling out in the areas of reduced current velocities where opposing streams meet

Geon-type solutions of the non-linear Heisenberg-Klein-Gordon equation

International Nuclear Information System (INIS)

Mielke, E.W.; Scherzer, R.

1980-10-01

As a model for a ''unitary'' field theory of extended particles we consider the non-linear Klein-Gordon equation - associated with a ''squared'' Heisenberg-Pauli-Weyl non-linear spinor equation - coupled to strong gravity. Using a stationary spherical ansatz for the complex scalar field as well as for the background metric generated via Einstein's field equation, we are able to study the effects of the scalar self-interaction as well as of the classical tensor forces. By numerical integration we obtain a continuous spectrum of localized, gravitational solitons resembling the geons previously constructed for the Einstein-Maxwell system by Wheeler. A self-generated curvature potential originating from the curved background partially confines the Schroedinger type wave functions within the ''scalar geon''. For zero angular momentum states and normalized scalar charge the spectrum for the total gravitational energy of these solitons exhibits a branching with respect to the number of nodes appearing in the radial part of the scalar field. Preliminary studies for higher values of the corresponding ''principal quantum number'' reveal that a kind of fine splitting of the energy levels occurs, which may indicate a rich, particle-like structure of these ''quantized geons''. (author)

Kaluza-Klein-Carmeli Metric from Quaternion-Clifford Space, Lorentz' Force, and Some Observables

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Christianto V.

2008-04-01

Full Text Available It was known for quite long time that a quaternion space can be generalized to a Clifford space, and vice versa; but how to find its neat link with more convenient metric form in the General Relativity theory, has not been explored extensively. We begin with a representation of group with non-zero quaternions to derive closed FLRW metric [1], and from there obtains Carmeli metric, which can be extended further to become 5D and 6D metric (which we propose to call Kaluza-Klein-Carmeli metric. Thereafter we discuss some plausible implications of this metric, beyond describing a galaxy’s spiraling motion and redshift data as these have been done by Carmeli and Hartnett [4, 5, 6]. In subsequent section we explain Podkletnov’s rotating disc experiment. We also note possible implications to quantum gravity. Further observations are of course recommended in order to refute or verify this proposition.

Some observations on hallucination: clinical application of some developments of Melanie Klein's work.

Science.gov (United States)

Taylor, D

1983-01-01

The analysis of a psychotic patient is used to illustrate the importance of certain developments of Melanie Klein's work. The case presentation focuses upon the formal qualities of the patient's communications, many of which were amalgamations of profoundly incompatible elements, particularly a subtle destructiveness which parasitized seemingly impartial reports about her state of mind. These communications embodied important object relationships. The patient used her communications to conjure up psychic disintegration. As a result of her involvement in 'chuntering' her preoccupations would become increasingly violent, cruel and sexualized. The patient's equivocal communications generate confusion. This is central to the patient's experience of self-destruction as persecution. A number of ideas are advanced concerning the origins of the patient's hallucinations. These include her relish at the introduction of sensory distortions. Questions are raised about the nature of certain types of hallucination, the origins and intractability of concrete thinking, about verbalization and about the typology of psychotic patients.

Hunting the ghosts of a 'strictly quantum field': the Klein-Gordon equation

International Nuclear Information System (INIS)

Bertozzi, Eugenio

2010-01-01

This paper aims to identify and tackle some problems related to teaching quantum field theory (QFT) at university level. In particular, problems arising from the canonical quantization are addressed by focusing on the Klein-Gordon equation (KGE). After a brief description of the status of the KGE in teaching as it emerges from an analysis of a selected sample of university textbooks, an analysis of the applications of the KGE in contexts different from the QFT is presented. The results of the analysis show that, while in the real case the solutions of the equation can be easily interpreted from a physical point of view, in the complex case the coherence with relativistic quantum mechanics and the electrodynamics framework brings to light interpretative problems related to the classical complex KG field. The comparison between the classical cases investigated and the QFT framework, where the equation finds a coherent particle interpretation, leads to share Ryder's statement asserting that the KG field is a 'strictly quantum field'. Implications of the results in terms of remarks about the canonical procedure currently utilized for teaching are underlined.

SPECT in the Kleine-Levin syndrome, a possible diagnostic and prognostic aid?

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Patrick Emanuel Vigren

2014-09-01

Full Text Available INTRODUCTION: Kleine-Levin syndrome (KLS is a rare syndrome of periodic hypersomnia and behavioral and cognitive symptoms based on clinical criteria. In the setting of differential diagnosis of hypersomnia disorders, an objective diagnostic aid is desirable. A promising modality is single photon emission computed tomography (SPECT. As intraepisodal investigations are difficult to perform, an interepisodal investigation would be very helpful. Another aim of the study was to correlate SPECT findings to prognosis. METHODS AND MATERIAL: 24 KLS-patients were categorized as severe or non-severe based on clinical characteristics. The clinical characteristics were analyzed in relation to SPECT-examinations performed between hypersomnia periods (interepisodal or after remission, as a clinical routine investigation.RESULTS: 48% of the KLS-patients have hypoperfusion in the temporal or fronto-temporal regions. In patients that have undergone remission, 56% show that pattern. There were no specific findings related to prognosis.DISCUSSION/CONCLUSION: SPECT might be a diagnostic aid, in a setting of hypersomnia experience. With a sensitivity of 48%, interepisodal SPECT alone cannot be used for diagnosing KLS.

The Euclidean scalar Green function in the five-dimensional Kaluza-Klein magnetic monopole space-time

International Nuclear Information System (INIS)

Bezerra de Mello, E.R.

2006-01-01

In this paper we present, in a integral form, the Euclidean Green function associated with a massless scalar field in the five-dimensional Kaluza-Klein magnetic monopole superposed to a global monopole, admitting a nontrivial coupling between the field with the geometry. This Green function is expressed as the sum of two contributions: the first one related with uncharged component of the field, is similar to the Green function associated with a scalar field in a four-dimensional global monopole space-time. The second contains the information of all the other components. Using this Green function it is possible to study the vacuum polarization effects on this space-time. Explicitly we calculate the renormalized vacuum expectation value * (x)Φ(x)> Ren , which by its turn is also expressed as the sum of two contributions

The role of tourist icons for a destination: the case of the closure of the Outeniqua Choo Choo train in the Eden District Municipality in the Western Cape Province, South Africa

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T Ramukumba

2014-01-01

Full Text Available Attractions are a major component of the tourism industry and often exert considerable influence over individual travel priorities. Attractions are one of the main motivators for tourist trips and are the core of the tourism product. Without attractions the destination would not need other tourism sectors and services. The uniqueness of attractions becomes an issue of greater significance in travel motivation for the visitors as they seek these unique tourism experiences around the world. The main aim of this paper was to look at the impact the closure of the Outeniqua Choo Choo train had to the tourism industry of the Eden District Municipality (EDM better known as the Garden Route and Klein Karoo region in the tourism industry. The train was considered to be an iconic attraction due to the unique experiences it offered to the tourists. The research used questionnaires as a survey technique to collect primary data and the questionnaires were emailed to all the tourism businesses that were registered at the Eden District Municipality (EDM database during the time of the train operations. One hundred and fifty questionnaires were distributed to the businesses and only one hundred and twenty were received back and none of them were spoilt and this represent 80% response rate. The study found that across the different businesses in the tourism industry of the Eden District Municipality, majority of them did benefited from the train operation and they would like to see the train revived back to operation. The strategies they would like to see being used to revive the train operations are municipal fund raising and private business raising funds themselves.

Using geospatial data analysis and qualitative economic intelligence to inform local economic development in small towns: a case study of Graaff-Reinet, South Africa

CSIR Research Space (South Africa)

Spocter, M

2011-01-01

Full Text Available hold collections of photographic memorabilia, firearms, artworks and fossils. These museums trace the story of the Karoo and the town from pre-history right up to the present day (Graaff- Reinet Chamber of Commerce, 2010). A number of well...

Kleine-Levin Syndrome in an 8-Year-Old Girl with Autistic Disorder: Does Autism Account a Primary or Secondary Cause?

Science.gov (United States)

Hakim Shoushtari, Mitra; Ghalebandi, Mirfarhad; Tavasoli, Azita; Pourshams, Maryam

2015-01-01

Objective Kleine-Levin syndrome (KLS) is a rare disorder with an unknown etiology. Autism spectrum disorder is characterized by various degrees of impairment in social communication, repetitive behavior and restricted interests. Only four patients of KLS with autistic spectrum disorder (ASD) have been reported so far. This report presents an 8-year-old girl with history of autistic disorder and epilepsy that superimposed KLS. Because of the rarity of KLS and related studies did not address whether autism accounts for a primary or secondary cause, the area required attention further studies.

Testing the Nature of Kaluza-Klein Excitations at Future Lepton Colliders

International Nuclear Information System (INIS)

Rizzo, Thomas G.

1999-01-01

With one extra dimension, current high precision electroweak data constrain the masses of the first Kaluza-Klein excitations of the Standard Model gauge fields to lie above ≅ 4 TeV. States with masses not much larger than this should be observable at the LHC. However, even for first excitation masses close to this lower bound, the second set of excitations will be too heavy to be produced thus eliminating the possibility of realizing the cleanest signature for KK scenarios. Previous studies of heavy $Z'$ and $W'$ production in this mass range at the LHC have demonstrated that very little information can be obtained about their couplings to the conventional fermions given the limited available statistics and imply that the LHC cannot distinguish an ordinary $Z'$ from the degenerate pair of the first KK excitations of the γ and Z. In this paper we discuss the capability of lepton colliders with center of mass energies significantly below the excitation mass to resolve this ambiguity. In addition, we examine how direct measurements obtained on and near the top of the first excitation peak at lepton colliders can confirm these results. For more than one extra dimension we demonstrate that it is likely that the first KK excitation is too massive to be produced at the LHC

Management of a Karoo fractured-rock aquifer system – Kalkveld ...

African Journals Online (AJOL)

2005-01-21

Jan 21, 2005 ... Institute for Groundwater Studies, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa .... resembles flow in a porous medium and therefore obeys ... that of the theoretical media usually presented in the literature ..... boundaries such as quaternary catchments, river systems and.

Impact of elephant on two woody trees, Boscia oleoides and Pappea capensis, in an arid thicket-Nama Karoo mosaic, Greater Addo Elephant National Park

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Marietjie Landman

2014-11-01

Full Text Available Despite extensive evidence of the influences of elephant on woody trees in savannah habitats, effects on trees in the succulent thickets of the Eastern Cape are relatively poorly described. Our study investigates the role and intensity of elephant impacts on Pappea capensis and the relatively rare Boscia oleoides in an arid thicket-Nama Karoo mosaic habitat of the Greater Addo Elephant National Park. We show that roughly 19% of the B. oleoides and nearly half of the P. capensis individuals recorded showed signs of elephant impact. Elephant often toppled our study trees, and where these individuals were uprooted, mortalities occurred: B. oleoides ~ 44% of the impacted trees (4 individuals; P. capensis ~ 22% of the impacted trees (29 individuals. Conservation implications: Whilst this study is restricted by limited spatial and temporal replication, P. capensis mortalities caused by elephant occurred at a rate exceeding that of other processes. Our results provide insight into the severity of the measured changes and the need to reduce the impacts. However, it would be critically important to establish the specific driver of elephant–tree interactions before any management intervention is implemented.

Os lugares do vazio: impressões antagônigas nos espaços de Georges Perec e Yves Klein

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Manlio de Medeiros Speranzini

2013-12-01

Full Text Available Este trabalho toma o livro Un homme qui dort, de Georges Perec, e o texto “La spécialisation de la sensibilité à l’état matière première en sensibilité picturale stabilisée”, do artista Yves Klein, para explorar as maneiras como esses autores, um pela escrita e o outro pela intervenção em uma galeria de arte, sensibilizam os espaços para revelar o vazio. As ideias de Georges Didi-Huberman, presentes no livro O que vemos, o que nos olha, servem para esclarecer a natureza antagônica do vazio que as duas obras suscitam.

Le discours publicitaire – un discours non-constituant - investigation de l’iconotexte dans la publicité pour le parfum Beauty créé par Calvin Klein -

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GAFENCU I. Tiberiu

2012-12-01

Full Text Available The advertising discourse is a non-constituent discourse. In what follows we shall present an analysis of the advertisement for the Calvin Klein perfume called “Beauty”. Our investigation is focused on the way in which the iconical component and the textual one convey the message of the advertising process by engaging in a reciprocal movement of response, thus completing each other.

Role of Aeolian Dust in Shaping Landscapes and Soils of Arid and Semi-Arid South Africa

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Joseph R. McAuliffe

2018-05-01

Full Text Available The deposition of fine aeolian sediment profoundly influences the morphology of several different landscapes of the arid and semi-arid western portion of South Africa. Such landscapes and features include: (1 regularly-spaced mounds known as heuweltjies of the succulent Karoo region, (2 barren stone pavements in the more arid regions, and (3 hillslopes with smooth, curvilinear slope profiles that are mantled with coarse, stony colluvium. Investigations of each of these are presented, together with comparisons of similar features found within arid and semi-arid portions of Western North America. Recent findings suggest that the formation of the distinct, regularly-spaced heuweltjies involves a linked set of biological and physical processes. These include nutrient accumulation by termites and the production of dense vegetation patches, which, in turn, serve as a trap for aeolian sediments. Dust deposition is also responsible for the formation of stone pavements as demonstrated by research conducted principally in the Mojave Desert region of the United States. Mineralogical and geochronological studies have demonstrated that the stone clasts remain on the surface as fine aeolian sediments are translocated downward beneath the clasts resulting in a silt-rich soil horizon directly beneath the clasts. Pavements examined in South Africa have the same morphological features that can only be explained by the same process. The formation of soils on hillslopes mantled with stony colluvium are commonly viewed as having formed through the in-situ weathering of the stony colluvium. However, like pavements, mantles of coarse, stony colluvium are effective dust traps that provide the long-term stability required for advanced development of thick, fine-grained soils. This process contributes to the evolution of smooth, vegetated, curvilinear slope profiles. In each of these examples, the accumulation of dust has a profound influence, not only in soil formation

Initial review and analysis of the direct environmental impacts of CSP in the northern Cape, South Africa

Science.gov (United States)

Rudman, Justine; Gauché, Paul; Esler, Karen J.

2016-05-01

The Integrated Resource Plan (IRP) of 2010 and the IRP Update provide the most recent guidance to the electricity generation future of South Africa (SA) and both plans include an increased proportion of renewable energy generation capacity. Given that SA has abundant renewable energy resource potential, this inclusion is welcome. Only 600 MW of the capacity allocated to concentrating solar power (CSP) has been committed to projects in the Northern Cape and represents roughly a fifth of the capacity that has been included in the IRP. Although CSP is particularly new in the electricity generation system of the country, the abundant solar resources of the region with annual DNI values of above 2900 kWh/m2 across the arid Savannah and Nama-Karoo biomes offer a promising future for the development of CSP in South Africa. These areas have largely been left untouched by technological development activities and thus renewable energy projects present a variety of possible direct and indirect environmental, social and economic impacts. Environmental Impact Assessments do focus on local impacts, but given that ecological processes often extend to regional- and landscape scales, understanding this scaled context is important to the alignment of development- and conservation priorities. Given the capacities allocated to CSP for the future of SA's electricity generation system, impacts on land, air, water and biodiversity which are associated with CSP are expected to increase in distribution and the understanding thereof deems valuable already from this early point in CSP's future in SA. We provide a review of direct impacts of CSP on the natural environment and an overview of the anticipated specific significance thereof in the Northern Cape.

The remedial conservation and support jacketing of the Massospondylus carinatus neotype

OpenAIRE

Graham, M; Choiniere, JN; Jirah, S; Barrett, PM

2018-01-01

0000-0002-1852-9709 Massopondylus carinatus Owen, 1854 is a non-sauropodan sauropodomorph (‘prosauropod’) dinosaur whose remains are abundant in the Upper Karoo Supergroup sediments of southern Africa (e.g. Owen, 1854; Seeley, 1895; Cooper, 1981; Gow, 1990; Gow et al., 1990; Sues et al., 2004; Barrett and Yates, 2006; Reisz et al., 2005). It occurs at numerous localities in the Upper Elliot and Clarens formations of South Africa and Lesotho, as well as in the Forest Sandstone Formation of ...

Semiclassical Klein-Kramers and Smoluchowski equations for the Brownian motion of a particle in an external potential

International Nuclear Information System (INIS)

Coffey, W T; Kalmykov, Yu P; Titov, S V; Mulligan, B P

2007-01-01

The quantum Brownian motion of a particle in an external potential V(x) is treated using the master equation for the Wigner distribution function W(x, p, t) in phase space (x, p). A heuristic method of determination of diffusion coefficients in the master equation is proposed. The time evolution equation so obtained contains explicit quantum correction terms up to o(ℎ 4 ) and in the classical limit, ℎ → 0, reduces to the Klein-Kramers equation. For a quantum oscillator, the method yields an evolution equation for W(x, p, t) coinciding with that of Agarwal (1971 Phys. Rev. A 4 739). In the non-inertial regime, by applying the Brinkman expansion of the momentum distribution in Weber functions (Brinkman 1956 Physica 22 29), the corresponding semiclassical Smoluchowski equation is derived. (fast track communication)

Waardenburg syndrome type 3 (Klein-Waardenburg syndrome) segregating with a heterozygous deletion in the paired box domain of PAX3: a simple variant or a true syndrome?

Science.gov (United States)

Tekin, M; Bodurtha, J N; Nance, W E; Pandya, A

2001-10-01

Klein-Waardenburg syndrome or Waardenburg syndrome type 3 (WS-III; MIM 148820) is characterized by the presence of musculoskeletal abnormalities in association with clinical features of Waardenburg syndrome type 1 (WS-I). Since the description of the first patient in 1947 (D. Klein, Arch Klaus Stift Vererb Forsch 1947: 22: 336-342), a few cases have been reported. Only occasional families have demonstrated autosomal-dominant inheritance of WS-III. In a previous report, a missense mutation in the paired domain of the PAX3 gene has been described in a family with dominant segregation of WS-III. In this report, we present a second family (mother and son) with typical clinical findings of WS-III segregating with a heterozygous 13-bp deletion in the paired domain of the PAX3 gene. Although homozygosity or compound heterozygosity has also been documented in patients with severe limb involvement, a consistent genotype-phenotype correlation for limb abnormalities associated with heterozygous PAX3 mutations has not previously been apparent. Heterozygous mutations could either reflect a unique dominant-negative effect or possibly the contribution of other unlinked genetic modifiers in determining the phenotype.

Long-term landscape evolution of the South Atlantic passive continental margin along the Kaoko- and Damara Belts, NW-Namibia

Science.gov (United States)

Menges, Daniel; Glasmacher, Ulrich Anton; Hackspacher, Peter; Schneider, Gabriele; Salomon, Eric

2015-04-01

The Kaoko Belt in northwestern Namibia originates in the collision of the Rio de la Plata and Kongo Craton during the Pan-African Orogeny in the Neoproterozoic (1) and represents the northern arm of the Damara Orogen. NW-Namibias continental crust mainly consists of the NE-SW striking intracontinental branch of the Pan-African Damara mobile belt, which separates the Congo from the Kalahari craton. The Damara Orogen is divided into several tectonostratigraphic zones that are bounded by steeply dipping, ductile shear zones. These regional lineaments can be traced at least 150 km offshore (2). The lithostratigraphic units consist of Proterozoic and Cambrian metamorphosed rocks (534 (7) Ma - 481 (25) Ma (3) as well as Mesozoic sedimentary and igneous rocks. From Permo-Carboniferous to Mid Jurassic northern Namibia was affected by deep erosion of the Damara Orogen, Permo-Triassic collisional processes along the southern margin of Gondwana and eastern margin of Africa (4), and the deposition of the Nama Group sediments and the Karoo megasequence (5). Between the Otjihorongo and the Omaruru Lineament-Waterberg Thrust early Mesozoic tectonic activity is recorded by coarse clastic sediments deposited within NE trending half-graben structures. The Early Jurassic Karoo flood basalt lavas erupted rapidly at 183±1 Ma (6). The Early Cretaceous Paraná-Etendeka flood basalts (132±1 Ma) and mafic dike swarms mark the rift stage of the opening of the South Atlantic (7). Early Cretaceous alkaline intrusions (137-124 Ma) occur preferentially along Mesozoic half-graben structures and are called the Damaraland Igneous Province (8). Late Cretaceous alkaline intrusions and kimberlite pipes occur in northern Namibia. Post Early Paleocene siliciclastic sedimentation in Namibia was largely restricted to a 150 km wide zone (9) and is represented by the Tsondab Sandstone Formation (~ 300 m thickness). The oldest part has an age of early Paleocene and the upper part span from middle Miocene

Surmounting the Cartesian Cut Through Philosophy, Physics, Logic, Cybernetics, and Geometry: Self-reference, Torsion, the Klein Bottle, the Time Operator, Multivalued Logics and Quantum Mechanics

Science.gov (United States)

Rapoport, Diego L.

2011-01-01

In this transdisciplinary article which stems from philosophical considerations (that depart from phenomenology—after Merleau-Ponty, Heidegger and Rosen—and Hegelian dialectics), we develop a conception based on topological (the Moebius surface and the Klein bottle) and geometrical considerations (based on torsion and non-orientability of manifolds), and multivalued logics which we develop into a unified world conception that surmounts the Cartesian cut and Aristotelian logic. The role of torsion appears in a self-referential construction of space and time, which will be further related to the commutator of the True and False operators of matrix logic, still with a quantum superposed state related to a Moebius surface, and as the physical field at the basis of Spencer-Brown's primitive distinction in the protologic of the calculus of distinction. In this setting, paradox, self-reference, depth, time and space, higher-order non-dual logic, perception, spin and a time operator, the Klein bottle, hypernumbers due to Musès which include non-trivial square roots of ±1 and in particular non-trivial nilpotents, quantum field operators, the transformation of cognition to spin for two-state quantum systems, are found to be keenly interwoven in a world conception compatible with the philosophical approach taken for basis of this article. The Klein bottle is found not only to be the topological in-formation for self-reference and paradox whose logical counterpart in the calculus of indications are the paradoxical imaginary time waves, but also a classical-quantum transformer (Hadamard's gate in quantum computation) which is indispensable to be able to obtain a complete multivalued logical system, and still to generate the matrix extension of classical connective Boolean logic. We further find that the multivalued logic that stems from considering the paradoxical equation in the calculus of distinctions, and in particular, the imaginary solutions to this equation

Factors influencing specialist outreach and support services to rural populations in the Eden and Central Karoo districts of the Western Cape.

Science.gov (United States)

Schoevers, Johan; Jenkins, Louis

2015-04-21

Access to health care often depends on where one lives. Rural populations have significantly poorer health outcomes than their urban counterparts. Specialist outreach to rural communities is one way of improving access to care. A multifaceted style of outreach improves access and health outcomes, whilst a shifted outpatients style only improves access. In principle, stakeholders agree that specialist outreach and support (O&S) to rural populations is necessary. In practice, however, factors influence whether or not O&S reaches its goals, affecting sustainability.Aim and setting: Our aim was to better understand factors associated with the success or failure of specialist O&S to rural populations in the Eden and Central Karoo districts in the Western Cape. An anonymous parallel three-stage Delphi process was followed to obtain consensus in a specialist and district hospital panel. Twenty eight specialist and 31 district hospital experts were invited, with response rates of 60.7%-71.4% and 58.1%-74.2% respectively across the three rounds. Relationships, communication and planning were found to be factors feeding into a service delivery versus capacity building tension, which affects the efficiency of O&S. The success of the O&S programme is dependent on a site-specific model that is acceptable to both the outreaching specialists and the hosting district hospital. Good communication, constructive feedback and improved planning may improve relationships and efficiency, which might lead to a more sustainable and mutually beneficial O&S system.

Widespread hypermetabolism in symptomatic and asymptomatic episodes in Kleine-Levin syndrome.

Directory of Open Access Journals (Sweden)

Yves Dauvilliers

Full Text Available BACKGROUND: No reliable biomarkers are identified in KLS. However, few functional neuroimaging studies suggested hypoactivity in thalamic and hypothalamic regions during symptomatic episodes. Here, we investigated relative changes in regional brain metabolism in Kleine-Levin syndrome (KLS during symptomatic episodes and asymptomatic periods, as compared to healthy controls. METHODS: Four drug-free male patients with typical KLS and 15 healthy controls were included. 18-F-fluorodeoxy glucose positron emission tomography (PET was obtained in baseline condition in all participants, and during symptomatic episodes in KLS patients. All participants were asked to remain fully awake during the whole PET procedure. RESULTS: Between state-comparisons in KLS disclosed higher metabolism in paracentral, precentral, and postcentral areas, supplementary motor area, medial frontal gyrus, thalamus and putamen during symptomatic episodes, and decreased metabolism in occipital and temporal gyri. As compared to healthy control subjects, KLS patients in the asymptomatic phase consistently exhibited significant hypermetabolism in a wide cortical network including frontal and temporal cortices, posterior cingulate and precuneus, with no detected hypometabolism. In symptomatic KLS episodes, hypermetabolism was additionally found in orbital frontal and supplementary motor areas, insula and inferior parietal areas, and right caudate nucleus, and hypometabolism in the middle occipital gyrus and inferior parietal areas. CONCLUSION: Our results demonstrated significant hypermetabolism and few hypometabolism in specific but widespread brain regions in drug-free KLS patients at baseline and during symptomatic episodes, highlighting the behavioral state-dependent nature of changes in regional brain activity in KLS.

Safeguarding biodiversity and ecosystem services in the Little Karoo, South Africa

CSIR Research Space (South Africa)

Egoh, Benis N

2010-02-01

Full Text Available of conservation interventions. The benefits of such integration are purported to include improvements in the justification and resources available for these interventions. Nevertheless, additional costs and potential trade-offs remain poorly understood...

Representations of nurses and individuals in psychological distress in the photographic exhibit USAnatomy, by Steven Klein.

Science.gov (United States)

Carvalho, Evanilda Souza de Santana; Araújo, Edna Maria de; Santos, Silvone Santa Bárbara da Silva; Santos, Alexandro Gesner Gomes Dos

2016-06-01

Objectives To analyze the representations of the nurse and individual in mental suffering portrayed in the photographic work by Steven Klein, in the USAnatomy exhibit held at the Museum of Sculpture (Museu da escultura) in São Paulo, in 2011. Methods Qualitative study carried out in 2012. Three photographs were submitted to iconographic analysis. The interpretation of the findings was based on theoretical frameworks of Foucault and Bourdieu on power relations. Results The nurse is represented as a sensual, insensitive person, with the power to control and torture while the person in psychological distress is represented as dirty, imprisoned and subjected to an asymmetrical relationship of power with the nurse. Final considerations Relationships of submission and symbolic dominance, in which the person in psychological distress has their body molded by discipline imposed by the nurse. Stereotypes of the image of the nurse oppose the ideology of the profession, which is to ensure the integrity of those being cared for.

Municipal Boundary Demarcation in South Africa: Processes and ...

African Journals Online (AJOL)

User

A multiple method research approach was adopted for the collection of data through ... the water in the Klein Letaba River dried up and Crystalfontein Farm 57 was ... provides for the restitution of land rights to those dispossessed, supported by an ..... traditional land administration system to make decisions over land ...

Spin- and valley-polarized one-way Klein tunneling in photonic topological insulators.

Science.gov (United States)

Ni, Xiang; Purtseladze, David; Smirnova, Daria A; Slobozhanyuk, Alexey; Alù, Andrea; Khanikaev, Alexander B

2018-05-01

Recent advances in condensed matter physics have shown that the spin degree of freedom of electrons can be efficiently exploited in the emergent field of spintronics, offering unique opportunities for efficient data transfer, computing, and storage ( 1 - 3 ). These concepts have been inspiring analogous approaches in photonics, where the manipulation of an artificially engineered pseudospin degree of freedom can be enabled by synthetic gauge fields acting on light ( 4 - 6 ). The ability to control these degrees of freedom significantly expands the landscape of available optical responses, which may revolutionize optical computing and the basic means of controlling light in photonic devices across the entire electromagnetic spectrum. We demonstrate a new class of photonic systems, described by effective Hamiltonians in which competing synthetic gauge fields, engineered in pseudospin, chirality/sublattice, and valley subspaces, result in bandgap opening at one of the valleys, whereas the other valley exhibits Dirac-like conical dispersion. We show that this effective response has marked implications on photon transport, among which are as follows: (i) a robust pseudospin- and valley-polarized one-way Klein tunneling and (ii) topological edge states that coexist within the Dirac continuum for opposite valley and pseudospin polarizations. These phenomena offer new ways to control light in photonics, in particular, for on-chip optical isolation, filtering, and wave-division multiplexing by selective action on their pseudospin and valley degrees of freedom.

Mutations in the paired domain of the human PAX3 gene cause Klein-Waardenburg syndrome (WS-III) as well as Waardenburg syndrome type I (WS-I).

OpenAIRE

Hoth, C F; Milunsky, A; Lipsky, N; Sheffer, R; Clarren, S K; Baldwin, C T

1993-01-01

Waardenburg syndrome type I (WS-I) is an autosomal dominant disorder characterized by sensorineural hearing loss, dystopia canthorum, pigmentary disturbances, and other developmental defects. Klein-Waardenburg syndrome (WS-III) is a disorder with many of the same characteristics as WS-I and includes musculoskeletal abnormalities. We have recently reported the identification and characterization of one of the first gene defects, in the human PAX3 gene, which causes WS-I. PAX3 is a DNA-binding ...

Kaluza-Klein Multidimensional Models with Ricci-Flat Internal Spaces: The Absence of the KK Particles

Directory of Open Access Journals (Sweden)

Alexey Chopovsky

2013-01-01

Full Text Available We consider a multidimensional Kaluza-Klein (KK model with a Ricci-flat internal space, for example, a Calabi-Yau manifold. We perturb this background metrics by a system of gravitating masses, for example, astrophysical objects such as our Sun. We suppose that these masses are pressureless in the external space but they have relativistic pressure in the internal space. We show that metric perturbations do not depend on coordinates of the internal space and gravitating masses should be uniformly smeared over the internal space. This means, first, that KK modes corresponding to the metric fluctuations are absent and, second, particles should be only in the ground quantum state with respect to the internal space. In our opinion, these results look very unnatural. According to statistical physics, any nonzero temperature should result in fluctuations, that is, in KK modes. We also get formulae for the metric correction terms which enable us to calculate the gravitational tests: the deflection of light, the time-delay of the radar echoes, and the perihelion advance.

Low-capacity wind power systems. Technology, legal aspects, economic efficiency; Kleine Windenergieanlagen. Technik - Recht - Wirtschaftlichkeit

Energy Technology Data Exchange (ETDEWEB)

Eggersgluess, Walter [Landwirtschaftskammer Schleswig-Holstein, Rendsburg (Germany); Eckel, Henning; Hartmann, Stefan [Kuratorium fuer Technik und Bauwesen in der Landwirtschaft e.V. (KTBL), Darmstadt (Germany)

2012-07-01

In what conditions will investments in a low-capacity wind power plant be profitable? This leaflet intends to provide a decision aid for farmers and other land owners interested in thes subject. It outlines the technology of low-capacity wind power systems, goes into site selection, expected yields and legal boundary conditions. The most important economic data are defined, and the economic efficiency of wind power plants of 7.5 to 25 kW is discussed. The text is supplemented by useful internet links. [German] Unter welchen Bedingungen rechnet sich die Investition in eine kleine Windenergieanlage? Das Heft hilft Landwirten sowie allen anderen investitionswilligen Grundstueckseigentuemern fuer sich Antworten auf diese Fragen zu finden und die richtigen Entscheidungen zu treffen. Es gibt einen Ueberblick ueber die Technik kleiner Windenergieanlagen, beschreibt was den richtigen Standort auszeichnet, mit welchen Energieertraegen gerechnet werden kann und welchen rechtlichen Rahmenbedingungen Bau und Betrieb der Anlagen unterliegen. Die wichtigsten wirtschaftlichen Kenngroessen werden definiert und die Wirtschaftlichkeit kleiner Windenergieanlagen anhand von Beispielanlagen im Leistungsbereich von 7,5 bis 25 kW diskutiert. Nuetzliche Internetadressen zum Thema Windenergie runden das Informationsangebot ab.

Spaces of positive and negative frequency solutions of field equations in curved space--times. I. The Klein--Gordon equation in stationary space--times

International Nuclear Information System (INIS)

Moreno, C.

1977-01-01

In stationary space--times V/sub n/ x R with compact space-section manifold without boundary V/sub n/, the Klein--Gordon equation is solved by the one-parameter group of unitary operators generated by the energy operator i -1 T -1 in the Sobolev spaces H/sup l/(V/sub n/) x H/sup l/(V/sub n/). The canonical symplectic and complex structures of the associated dynamical system are calculated. The existence and the uniqueness of the Lichnerowicz kernel are established. The Hilbert spaces of positive and negative frequency-part solutions defined by means of this kernel are constructed

A generalized auxiliary equation method and its application to nonlinear Klein-Gordon and generalized nonlinear Camassa-Holm equations

International Nuclear Information System (INIS)

Yomba, Emmanuel

2008-01-01

With the aid of symbolic computation, a generalized auxiliary equation method is proposed to construct more general exact solutions to two types of NLPDEs. First, we present new family of solutions to a nonlinear Klein-Gordon equation, by using this auxiliary equation method including a new first-order nonlinear ODE with six-degree nonlinear term proposed by Sirendaoreji. Then, we apply an indirect F-function method very close to the F-expansion method to solve the generalized Camassa-Holm equation with fully nonlinear dispersion and fully nonlinear convection C(l,n,p). Taking advantage of the new first-order nonlinear ODE with six degree nonlinear term, this indirect F-function method is used to map the solutions of C(l,n,p) equations to those of that nonlinear ODE. As a result, we can successfully obtain in a unified way, many exact solutions

Writeshops: An effective tool to enable African academics to publish

CSIR Research Space (South Africa)

Vincent, K

2012-08-01

Full Text Available -1 Writeshops: An effective tool to enable African academics to publish Vincent*, K., T. Cull, (Kulima Integrated Development Solutions, South Africa) E. Archer van Garderen, (CSIR, South Africa) and A. Awiti, (Aga Khan University, Kenya) * Corresponding... Seipt, Lisa Schipper and Richard J. T. Klein for their commitment to writeshops, and for various discussions on improving the accessibility of developing country researchers to the peer-reviewed literature. ...

The sleep architecture of Saudi Arabian patients with Kleine-Levin syndrome

Science.gov (United States)

Al Shareef, Saad M.; Almeneessier, Aljohara S.; Hammad, Omeima; Smith, Richard M.; BaHammam, Ahmed S.

2018-01-01

Objectives: To establish baseline sleep architecture during an acute attack of Kleine-Levin syndrome (KLS) in a cohort of Saudi Arabian KLS patients and compare these characteristics with other published cohorts. Methods: This was a retrospective cohort study of the polysomnographic characteristics of 10 typical symptomatic Saudi Arabian KLS patients attending the University Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia between 2002 and 2015. Data were captured by nocturnal polysomnography during an acute attack of hypersomnia and compared with other published cohorts identified via a systematic literature search. Results: Self-reported time asleep during episodes (11.1±6.7 hours) and recorded total sleep time (TST) (322.5±108.7 minutes) were generally shorter than other published cohorts. Sleep efficiency was poor at 75.0%±25.1%, with low relative amounts of rapid eye movement (REM) sleep (16.5±5.9% of TST) and deep non-REM sleep (stage N3; 10.5±6.0% of TST) and high relative amounts of non-REM sleep (stage N1; 7.0±4.3% of TST). The sleep architecture of Saudi Arabian KLS patients was similar to other published cohorts. Conclusions: Sleep architecture of our cohort was relatively normal and broadly similar to other published studies, the main features being low sleep efficiency and low relative amounts of REM and stage N3 sleep. Time-course polysomnography studies with functional imaging may be useful to further establish the exact pathophysiology of this disease. PMID:29332107

Evolutionary history of a keystone pollinator parallels the biome occupancy of angiosperms in the Greater Cape Floristic Region.

Science.gov (United States)

de Jager, Marinus L; Ellis, Allan G

2017-02-01

The Greater Cape Floristic Region (GCFR) in South Africa has been extensively investigated for its phenomenal angiosperm diversity. A key emergent pattern is the occurrence of older plant lineages in the southern Fynbos biome and younger lineages in the northern Succulent Karoo biome. We know practically nothing, however, about the evolutionary history of the animals that pollinate this often highly-specialized flora. In this study, we explore the evolutionary history of an important GCFR fly pollinator, Megapalpus capensis, and ask whether it exhibits broadly congruent genetic structuring and timing of diversification to flowering plants within these biomes. We find that the oldest M. capensis lineages originated in Fynbos during the Miocene, while younger Succulent Karoo lineages diverged in the Pliocene and correspond to the proposed age of this recent biome. A strong signature of population expansion is also recovered for flies in this arid biome, consistent with recent colonization. Our first investigation into the evolutionary history of GCFR pollinators thus supports a recent origin of the SK biome, as inferred from angiosperm phylogenies, and suggests that plants and pollinators may have co-diverged within this remarkable area. Copyright © 2016 Elsevier Inc. All rights reserved.

Temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with a soft on-site potential.

Science.gov (United States)

Yang, Linlin; Li, Nianbei; Li, Baowen

2014-12-01

The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.

Temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with a soft on-site potential

Science.gov (United States)

Yang, Linlin; Li, Nianbei; Li, Baowen

2014-12-01

The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.

Spin- and valley-polarized one-way Klein tunneling in photonic topological insulators

Science.gov (United States)

Slobozhanyuk, Alexey

2018-01-01

Recent advances in condensed matter physics have shown that the spin degree of freedom of electrons can be efficiently exploited in the emergent field of spintronics, offering unique opportunities for efficient data transfer, computing, and storage (1–3). These concepts have been inspiring analogous approaches in photonics, where the manipulation of an artificially engineered pseudospin degree of freedom can be enabled by synthetic gauge fields acting on light (4–6). The ability to control these degrees of freedom significantly expands the landscape of available optical responses, which may revolutionize optical computing and the basic means of controlling light in photonic devices across the entire electromagnetic spectrum. We demonstrate a new class of photonic systems, described by effective Hamiltonians in which competing synthetic gauge fields, engineered in pseudospin, chirality/sublattice, and valley subspaces, result in bandgap opening at one of the valleys, whereas the other valley exhibits Dirac-like conical dispersion. We show that this effective response has marked implications on photon transport, among which are as follows: (i) a robust pseudospin- and valley-polarized one-way Klein tunneling and (ii) topological edge states that coexist within the Dirac continuum for opposite valley and pseudospin polarizations. These phenomena offer new ways to control light in photonics, in particular, for on-chip optical isolation, filtering, and wave-division multiplexing by selective action on their pseudospin and valley degrees of freedom. PMID:29756032

Grain size statistics and depositional pattern of the Ecca Group sandstones, Karoo Supergroup in the Eastern Cape Province, South Africa

Directory of Open Access Journals (Sweden)

Baiyegunhi Christopher

2017-11-01

Full Text Available Grain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition of detrital sediments. In this study, detailed grain-size analysis was carried out on thirty-five sandstone samples from the Ecca Group in the Eastern Cape Province of South Africa. Grain-size statistical parameters, bivariate analysis, linear discriminate functions, Passega diagrams and log-probability curves were used to reveal the depositional processes, sedimentation mechanisms, hydrodynamic energy conditions and to discriminate different depositional environments. The grain-size parameters show that most of the sandstones are very fine to fine grained, moderately well sorted, mostly near-symmetrical and mesokurtic in nature. The abundance of very fine to fine grained sandstones indicate the dominance of low energy environment. The bivariate plots show that the samples are mostly grouped, except for the Prince Albert samples that show scattered trend, which is due to the either mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under shallow marine environments for samples from the Prince Albert, Collingham and Ripon Formations, while those samples from the Fort Brown Formation are lacustrine or deltaic deposits. The C-M plots indicated that the sediments were deposited mainly by suspension and saltation, and graded suspension. Visher diagrams show that saltation is the major process of transportation, followed by suspension.

Grain size statistics and depositional pattern of the Ecca Group sandstones, Karoo Supergroup in the Eastern Cape Province, South Africa

Science.gov (United States)

Baiyegunhi, Christopher; Liu, Kuiwu; Gwavava, Oswald

2017-11-01

Grain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition of detrital sediments. In this study, detailed grain-size analysis was carried out on thirty-five sandstone samples from the Ecca Group in the Eastern Cape Province of South Africa. Grain-size statistical parameters, bivariate analysis, linear discriminate functions, Passega diagrams and log-probability curves were used to reveal the depositional processes, sedimentation mechanisms, hydrodynamic energy conditions and to discriminate different depositional environments. The grain-size parameters show that most of the sandstones are very fine to fine grained, moderately well sorted, mostly near-symmetrical and mesokurtic in nature. The abundance of very fine to fine grained sandstones indicate the dominance of low energy environment. The bivariate plots show that the samples are mostly grouped, except for the Prince Albert samples that show scattered trend, which is due to the either mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under shallow marine environments for samples from the Prince Albert, Collingham and Ripon Formations, while those samples from the Fort Brown Formation are lacustrine or deltaic deposits. The C-M plots indicated that the sediments were deposited mainly by suspension and saltation, and graded suspension. Visher diagrams show that saltation is the major process of transportation, followed by suspension.

[Kleine-Levin syndrome: state of the art].

Science.gov (United States)

Arnulf, I; Lecendreux, M; Franco, P; Dauvilliers, Y

2008-01-01

Kleine-Levin syndrome is a rare neurological disorder (1-2 cases per million inhabitants) primarily affecting young subjects. It is characterized by relapsing-remitting episodes of hypersomnia in association with cognitive and behavioral disturbances. Case-reports, small series, meta-analysis and a recent large, prospective trio study are consistent with a homogeneous, genuine disease entity. Patients are mostly male (68-78%) and adolescents (81%), with mean onset at 15 years (range 4-82 years). The first episode is triggered by an infection in 72% of patients. Patients experience an average of 7-19 episodes of 10-13 days each, relapsing every 3.5 months. Episodes recur more quickly in patients with childhood onset. The median disease course is 8-14 years, with longer course in men, in patients with hypersexuality, and when onset is after age 20. During episodes, all patients have hypersomnia (with sleep lasting 15-21 heures per day), cognitive impairment (apathy, confusion, slowness, amnesia) and a specific feeling of derealization (dreamy state, altered perception). Less frequently, patients experience hyperphagia (66%), hypersexuality (53%, principally men) and depressed mood (53%, predominantly women). Patients are remarkably similar to controls between episodes regarding sleep, vigilance, mood, and eating attitude, but have increased body mass index. Structural brain imaging, evaluation of the cerebrospinal fluid and serological inflammatory markers are unremarkable. EEG slowing is notable in 70% of cases during episodes, without epileptic activity. Sleep structure varies from harmonious hypersomnia to hypo-arousal with low sleep efficiency. The brain scintigraphy may show hypoperfusion, mostly focused on the thalamic, hypothalamic and fronto-temporal areas, especially when contrasted to images obtained between episodes. Newly identified factors include increased birth and developmental problems, Jewish heritage, genetics (5% multiplex families, suggesting

Axisymmetric black holes allowing for separation of variables in the Klein-Gordon and Hamilton-Jacobi equations

Science.gov (United States)

Konoplya, R. A.; Stuchlík, Z.; Zhidenko, A.

2018-04-01

We determine the class of axisymmetric and asymptotically flat black-hole spacetimes for which the test Klein-Gordon and Hamilton-Jacobi equations allow for the separation of variables. The known Kerr, Kerr-Newman, Kerr-Sen and some other black-hole metrics in various theories of gravity are within the class of spacetimes described here. It is shown that although the black-hole metric in the Einstein-dilaton-Gauss-Bonnet theory does not allow for the separation of variables (at least in the considered coordinates), for a number of applications it can be effectively approximated by a metric within the above class. This gives us some hope that the class of spacetimes described here may be not only generic for the known solutions allowing for the separation of variables, but also a good approximation for a broader class of metrics, which does not admit such separation. Finally, the generic form of the axisymmetric metric is expanded in the radial direction in terms of the continued fractions and the connection with other black-hole parametrizations is discussed.

Modelling the distribution of tritium in groundwater across South Africa to assess the vulnerability and sustainability of groundwater resources in response to climate change

Science.gov (United States)

van Rooyen, Jared; Miller, Jodie; Watson, Andrew; Butler, Mike

2017-04-01

Groundwater is critical for sustaining human populations, especially in semi-arid to arid areas, where surface water availability is low. Shallow groundwater is usually abstracted for this purpose because it is the easiest to access and assumed to be renewable and regularly recharged by precipitation. Renewable, regularly recharged groundwater is also called modern groundwater, ie groundwater that has recently been in contact with the atmosphere. Tritium can be used to determine whether or not a groundwater resource is modern because the half-life of tritium is only 12.36 years and tritium is dominantly produced in the upper atmosphere and not in the rock mass. For this reason, groundwater with detectable tritium activities likely has a residence age of less than 50 years. In this study, tritium activities in 277 boreholes distributed across South Africa were used to develop a national model for tritium activity in groundwater in order to establish the extent of modern groundwater across South Africa. The tritium model was combined with modelled depth to water using 3079 measured static water levels obtained from the National Groundwater Archive and validated against a separate set of 40 tritium activities along the west coast of South Africa. The model showed good agreement with the distribution of rainfall which has been previously documented across the globe (Gleeson et al., 2015), although the arid Karoo basin in south west South Africa shows higher than expected tritium levels given the very low regional precipitation levels. To assess the vulnerability of groundwater to degradation in quality and quantity, the tritium model was incorporated into a multi-criteria evaluation (MCE) model which incorporated other indicators of groundwater stress including mean annual precipitation, mean annual surface temperature, electrical conductivity (as a proxy for groundwater salinization), potential evaporation, population density and cultivated land usage. The MCE model

Palaeochannels and uranium mineralisation in the main Karoo basin of South Africa

International Nuclear Information System (INIS)

Le Roux, J.P.

1985-01-01

The reconnaissance work made it clear that a better understanding of sedimentological controls over uranium mineralization could only be attained through detailed studies of specific prospects, preferably those where adequate drilling data were available. A research program was therefore launched with the following principal aims in mind: 1) to reconstruct the sedimentological environments as accurately as possible; 2) to establish the influence of depositional sub-environments on uranium mineralization; 3) to examine the possibility of finding extensions to known ore bodies, based on the local relationship between uranium mineralization and sedimentation patterns; 4) to formulate models of ore genesis which may aid in the delineation of new target areas for uranium exploration

Kaluza-Klein models: Can we construct a viable example?

International Nuclear Information System (INIS)

Eingorn, Maxim; Zhuk, Alexander

2011-01-01

In Kaluza-Klein models with toroidal compactification of the extra dimensions, we investigate soliton solutions of Einstein equation. The nonrelativistic gravitational potential of these solitons exactly coincides with the Newtonian one. We obtain the formulas for perihelion shift, deflection of light, time delay of radar echoes and post-Newtonian (PPN) parameters. Using the constraint on PPN parameter γ, we find that the solitonic parameter k should be very big: |k|≥2.3x10 4 . We define a soliton solution which corresponds to a pointlike mass source. In this case the soliton parameter k=2, which is clearly contrary to this restriction. A similar problem with the observations takes place for static spherically symmetric perfect fluid with the dustlike equation of state in all dimensions. The common for both of these models is the same (dustlike) equations of state in our three dimensions and in the extra dimensions. All dimensions are treated at equal footing. This is the crucial point. To be in agreement with observations, it is necessary to break the symmetry (in terms of equations of state) between the external/our and internal spaces. It takes place for black strings which are particular examples of solitons with k→∞. For such k, black strings are in concordance with the observations. Moreover, we show that they are the only solitons which are at the same level of agreement with the observations as in general relativity. Black strings can be treated as perfect fluid with dustlike equation of state p 0 =0 in the external/our space and very specific equation of state p 1 =-(1/2)ε in the internal space. The latter equation is due to negative tension in the extra dimension. We also demonstrate that dimension 3 for the external space is a special one. Only in this case we get the latter equation of state. We show that the black string equations of state satisfy the necessary condition of the internal space stabilization. Therefore, black strings are good

South-South Migration and Remittances

OpenAIRE

Ratha, Dilip; Shaw, William

2007-01-01

South-South Migration and Remittances reports on preliminary results from an ongoing effort to improve data on bilateral migration stocks. It sets out some working hypotheses on the determinants and socioeconomic implications of South-South migration. Contrary to popular perception that migration is mostly a South-North phenomenon, South-South migration is large. Available data from nation...

Scale challenges of the MeerKAT Radio Telescope

CERN Multimedia

CERN. Geneva; Ratcliffe, Simon

2017-01-01

A discussion on the MeerKAT Radio Telescope, currently nearing completion in the Karoo desert region of South Africa. This talk covers a quick introduction to radio astronomy data processing and the scale challenges inherent therein. The solutions to the challenges posed will be discussed, including coverage of our MESOS based execution framework and the role of the various data storage regimes in our processing and analysis pipelines. The final third will highlight our multiple uses of CEPH, including our self-build hardware, 20PB science archive. About the speakers Simon Ratcliffe has a background in astrophysics and computer science, and is currently the technical lead for scientific computing at SKA South Africa. In this role he oversees the architecture and technical direction of the science processor for the MeerKAT radio telescope. Thomas Bennett has a masters degree in electronic engineering and is currently a developer in the scientific computing as SKA South Africa. In this role he overs...

The elusive concept of 'internal objects' (1934-1943). Its role in the formation of the Klein Group.

Science.gov (United States)

Hinshelwood, R D

1997-10-01

The author traces a debate about the concept of 'internal objects' that took place between 1937 and 1943 at a time when a group of British analysts was forming around Melanie Klein. The debate is set within a complex of personal, group and organisational dynamics, which the paper makes a start on unravelling. The history of the British Psycho-Analytical Society at this time exemplifies Bion's notion of group schism. The events in the Society's history demonstrate defensive aspects of the interaction between the opposed groups, which support members against various anxieties. These include the stress of the work of analysis, but also in this instance the particular anxieties deriving from the collapse of psychoanalysis in Europe, the state of war of the country as a whole, and the death of Freud shortly after he came to London. This psychoanalytic anxiety/defence model clarifies some aspects of the debate about internal objects, and demonstrates the way in which these various anxieties and defences become organised around a scientific debate in a scientific society.

Impact of Prosopis (mesquite) invasion and clearing on vegetation ...

African Journals Online (AJOL)

We evaluated the impact of Prosopis invasion and clearing on vegetation species composition and diversity (alien and indigenous species richness and cover) in Nama-Karoo rangeland on two sheep farms in the Beaufort ... Keywords: invasive plants – exotic, Nama-Karoo, plant community ecology, rehabilitation, semi-arid ...

The solitary wave solution of coupled Klein-Gordon-Zakharov equations via two different numerical methods

Science.gov (United States)

Dehghan, Mehdi; Nikpour, Ahmad

2013-09-01

In this research, we propose two different methods to solve the coupled Klein-Gordon-Zakharov (KGZ) equations: the Differential Quadrature (DQ) and Globally Radial Basis Functions (GRBFs) methods. In the DQ method, the derivative value of a function with respect to a point is directly approximated by a linear combination of all functional values in the global domain. The principal work in this method is the determination of weight coefficients. We use two ways for obtaining these coefficients: cosine expansion (CDQ) and radial basis functions (RBFs-DQ), the former is a mesh-based method and the latter categorizes in the set of meshless methods. Unlike the DQ method, the GRBF method directly substitutes the expression of the function approximation by RBFs into the partial differential equation. The main problem in the GRBFs method is ill-conditioning of the interpolation matrix. Avoiding this problem, we study the bases introduced in Pazouki and Schaback (2011) [44]. Some examples are presented to compare the accuracy and easy implementation of the proposed methods. In numerical examples, we concentrate on Inverse Multiquadric (IMQ) and second-order Thin Plate Spline (TPS) radial basis functions. The variable shape parameter (exponentially and random) strategies are applied in the IMQ function and the results are compared with the constant shape parameter.

Weak-field limit of Kaluza-Klein models with spherically symmetric static scalar field. Observational constraints

Energy Technology Data Exchange (ETDEWEB)

Zhuk, Alexander [The International Center of Future Science of the Jilin University, Changchun City (China); Odessa National University, Astronomical Observatory, Odessa (Ukraine); Chopovsky, Alexey; Fakhr, Seyed Hossein [Odessa National University, Astronomical Observatory, Odessa (Ukraine); Shulga, Valerii [The International Center of Future Science of the Jilin University, Changchun City (China); Institut of Radio Astronomy of National Academy of Sciences of Ukraine, Kharkov (Ukraine); Wei, Han [The International Center of Future Science of the Jilin University, Changchun City (China)

2017-11-15

In a multidimensional Kaluza-Klein model with Ricci-flat internal space, we study the gravitational field in the weak-field limit. This field is created by two coupled sources. First, this is a point-like massive body which has a dust-like equation of state in the external space and an arbitrary parameter Ω of equation of state in the internal space. The second source is a static spherically symmetric massive scalar field centered at the origin where the point-like massive body is. The found perturbed metric coefficients are used to calculate the parameterized post-Newtonian (PPN) parameter γ. We define under which conditions γ can be very close to unity in accordance with the relativistic gravitational tests in the solar system. This can take place for both massive or massless scalar fields. For example, to have γ ∼ 1 in the solar system, the mass of scalar field should be μ >or similar 5.05 x 10{sup -49} g ∝ 2.83 x 10{sup -16} eV. In all cases, we arrive at the same conclusion that to be in agreement with the relativistic gravitational tests, the gravitating mass should have tension: Ω = -1/2. (orig.)

Patterns of distribution and current protection status of the Carnivora ...

African Journals Online (AJOL)

Endemism in Chiroptera is low, however, with only two endemic species in the fynbos and Karoo biomes. The Carnivora display less biome specificity and endemism than the Chiroptera. Whereas the north-eastern savannas have the highest species richness, the transition between the Nama-Karoo and grassland biomes ...

Methodology for obtaining a solution for the three-dimensional Boltzmann transport equation and an expression for the calculation of the total doses considering Compton scattering simulated by Klein-Nishina

International Nuclear Information System (INIS)

Rodriguez, Barbara A.; Borges, Volnei; Vilhena, Marco Tullio

2005-01-01

In this work we would like to obtain a formulation of an analytic method for the solution of the three dimensional transport equation considering Compton scattering and an expression for total doses due to gamma radiation, where the deposited energy by the free electron will be considered. For that, we will work with two equations: the first one for the photon transport, considering the Klein-Nishina kernel and energy multigroup model, and the second one considering the free electron with the screened Rutherford scattering. (author)

The grazing index method of range condition assessment | du Toit ...

African Journals Online (AJOL)

Owing to the difficulty of examining succession theory in the Karoo, it is suggested the ecological index method (EIM), be replaced by the grazing index method (GIM), through the introduction of grazing index values (GIV) for Karoo plant species. The GIM may provide more acceptable range condition scores and more ...

Professor Wheeler and the crack of doom: Closed cosmologies in the 5-d Kaluza-Klein theory

International Nuclear Information System (INIS)

Matzner, R.A.; Mezzacappa, A.

1986-01-01

We study the classical and the quantum structures of certain 5-d Kaluza-Klein cosmologies. These models were chosen because their 4-d restriction is a closed, radiation-dominated, homogeneous, isotropic cosmology in the usual sense. The extra (field) dimension is taken to be a circle. In these models the solution starts from a 5-d curvature singularity with infinite circumference for the circle and zero volume for the 3-space. It evolves in finite proper time to a solution with zero dimension for the extra field direction. In the 5-vacuum case this is not a curvature singularity, but is a singularity of the congruence describing the physics, and in particular, the solution cannot causally be extended to the future of this point. In the 5-vacuum case this event coincides with the maximum of expansion of the 5-space. In the 5-dust cases, this point is a real 5-d curvature singularity. By adjustment it can be made to occur before or after the maximum of 3-expansion. The solution stops at that instant, but the 4-cosmology reveals no pathology up to the crack of doom. The quantum behavior is identical in these respects to the classical one

Flavor changing neutral current constraints from Kaluza-Klein gluons and quark mass matrices in the Randall-Sundrum I framework

International Nuclear Information System (INIS)

Chang, W.-F.; Ng, John N.; Wu, Jackson M. S.

2009-01-01

We continue our previous study on what are the allowed forms of quark mass matrices in the Randall-Sundrum framework that can reproduce the experimentally observed quark mass spectrum and the pattern of Cabibbo-Kobayashi-Maskawa mixing. We study the constraints the ΔF=2 processes in the neutral meson sector placed on the admissible forms found there, and we found only the asymmetrical type of quark mass matrices arising from anarchical Yukawa structures remain viable at the few TeV scale reachable at the LHC. We study also the decay of the first Kaluza-Klein (KK) excitation of the gluon. We give the decay branching ratios of the first KK gluon into quark pairs, and we point out that measurements of the decay width and just one of the quark spins in the dominant tt decays can be used to extract the effective coupling of the first KK gluon to top quarks for both chiralities. This provides a further probe into the flavor structure of the Randall-Sundrum framework.

Putting fossils on the map: Applying a geographical information system to heritage resources

Directory of Open Access Journals (Sweden)

Merrill van der Walt

2015-11-01

Full Text Available A geographical information system (GIS database was compiled of Permo-Triassic tetrapod fossils from the Karoo Supergoup in South African museum collections. This database is the first of its kind and has great time applicability for understanding tetrapod biodiversity change though time more than 200 million years ago. Because the museum catalogues all differed in recorded information and were not compliant with field capture requirements, this information had to be standardised to a format that could be utilised for archival and research application. Our paper focuses on the processes involved in building the GIS project, capturing metadata on fossil collections and formulating future best practices. The result is a multi-layered GIS database of the tetrapod fossil record of the Beaufort Group of South Africa for use as an accurate research tool in palaeo- and geoscience research with applications for ecology, ecosystems, stratigraphy and basin development.

Titanates of the lindsleyite-mathiasite (LIMA) group reveal isotope disequilibrium associated with metasomatism in the mantle beneath Kimberley (South Africa)

Science.gov (United States)

Giuliani, Andrea; Woodhead, Jon D.; Phillips, David; Maas, Roland; Davies, Gareth R.; Griffin, William L.

2018-01-01

Radiogenic isotope variations unrelated to radiogenic ingrowth are common between minerals found in metasomatised mantle xenoliths entrained in kimberlite, basalts and related magmas. As the metasomatic minerals are assumed to have been in isotopic equilibrium originally, such variations are typically attributed to contamination by the magma host and/or interaction with mantle fluids during or before xenolith transport to surface. However, the increasing evidence of metasomatism by multiple, compositionally distinct fluids permeating the lithospheric mantle, coeval with specific magmatic events, suggests that isotopic disequilibrium might be a consequence of discrete, though complex, metasomatic events. Here we provide clear evidence of elemental and Sr isotope heterogeneity between coeval Ti-rich LIMA (lindsleyite-mathiasite) minerals at the time of their formation in the mantle. LIMA minerals occur in close textural association with clinopyroxene and phlogopite in low-temperature (∼800-900 °C), strongly metasomatised mantle xenoliths from the ∼84 Ma Bultfontein kimberlite (South Africa). Previous U/Pb dating of the LIMA phases was used to argue that each xenolith recorded a single event of LIMA crystallisation at ∼180-190 Ma, coeval with the emplacement of Karoo magmas. SEM imaging reveals that up to four types of LIMA phases coexist in each xenolith, and occasionally in a single LIMA grain. Major element and in situ Sr isotope analyses of the different LIMA types show that each phase has a distinct elemental composition and initial 87Sr/86Sr ratio (e.g., 0.7068-0.7086 and 0.7115-0.7129 for two LIMA types in a single xenolith; 0.7053-0.7131 across the entire sample suite). These combined age and isotopic constraints require that multiple fluids metasomatised these rocks at broadly the same time (i.e. within a few thousands to millions of years), and produced similar mineralogical features. Elemental and isotopic variations between different LIMA types

A novel SUSY energy bound-states treatment of the Klein-Gordon equation with PT-symmetric and q-deformed parameter Hulthén potential

Science.gov (United States)

Aktas, M.

2018-01-01

In this study, we focus on investigating the exact relativistic bound-state spectra for supersymmetric, PT-supersymmetric and non-Hermitian versions of the q-deformed parameter Hulthén potential. The Hamiltonian hierarchy mechanism, namely the factorization method, is adopted within the framework of SUSYQM. This algebraic approach is used in solving the Klein-Gordon equation with the potential cases. The results obtained analytically by executing the straightforward calculations are in consistent forms for certain values of q. Achieving the results may have a particular interest for such applications. That is, they can be involved in determining the quantum structural properties of molecules for ro-vibrational states, and optical spectra characteristics of semiconductor devices with regard to the lattice dynamics. They are also employed to construct the broken or unbroken case of the supersymmetric particle model concerning the interaction between the elementary particles.

Graviton production by two photon and electron-photon processes in Kaluza-Klein theories with large extra dimensions

International Nuclear Information System (INIS)

Atwood, David; Bar-Shalom, Shaouly; Soni, Amarjit

2000-01-01

We consider the production of gravitons via two photon and electron-photon fusion in Kaluza-Klein theories which allow TeV scale gravitational interactions. We show that at electron-positron colliders, the processes l + l - →l + l - +graviton, with l=e, μ, can lead to a new signal of low energy gravity of the form l + l - →l + l - +missing energy which is well above the standard model background. For example, with two extra dimensions, at the Next Linear Collider with a center of mass energy of 500 or 1000 GeV, hundreds to thousands such l + l - +graviton events may be produced if the scale of the gravitational interactions, M D , is around a few TeV. At a gamma-electron collider, more stringent bounds may be placed on M D via the related reaction e - γ→e - G. For instance, if a 1 TeV e + e - collider is converted to an electron-photon collider, a bound of ∼10(14) TeV may be placed on the scale M D if the number of extra dimensions δ=2, while a bound of ∼4(5) TeV may be placed if δ=4, with unpolarized (right polarized) electron beams. (c) 2000 The American Physical Society

Experimental climate warming decreases photosynthetic efficiency of lichens in an arid South African ecosystem.

Science.gov (United States)

Maphangwa, Khumbudzo Walter; Musil, Charles F; Raitt, Lincoln; Zedda, Luciana

2012-05-01

Elevated temperatures and diminished precipitation amounts accompanying climate warming in arid ecosystems are expected to have adverse effects on the photosynthesis of lichen species sensitive to elevated temperature and/or water limitation. This premise was tested by artificially elevating temperatures (increase 2.1-3.8°C) and reducing the amounts of fog and dew precipitation (decrease 30.1-31.9%), in an approximation of future climate warming scenarios, using transparent hexagonal open-top warming chambers placed around natural populations of four lichen species (Xanthoparmelia austroafricana, X. hyporhytida , Xanthoparmelia. sp., Xanthomaculina hottentotta) at a dry inland site and two lichen species (Teloschistes capensis and Ramalina sp.) at a humid coastal site in the arid South African Succulent Karoo Biome. Effective photosynthetic quantum yields ([Formula: see text]) were measured hourly throughout the day at monthly intervals in pre-hydrated lichens present in the open-top warming chambers and in controls which comprised demarcated plots of equivalent open-top warming chamber dimensions constructed from 5-cm-diameter mesh steel fencing. The cumulative effects of the elevated temperatures and diminished precipitation amounts in the open-top warming chambers resulted in significant decreases in lichen [Formula: see text]. The decreases were more pronounced in lichens from the dry inland site (decline 34.1-46.1%) than in those from the humid coastal site (decline 11.3-13.7%), most frequent and prominent in lichens at both sites during the dry summer season, and generally of greatest magnitude at or after the solar noon in all seasons. Based on these results, we conclude that climate warming interacting with reduced precipitation will negatively affect carbon balances in endemic lichens by increasing desiccation damage and reducing photosynthetic activity time, leading to increased incidences of mortality.

A response to Rudolf Klein: a battle may have been won but perhaps not the war.

Science.gov (United States)

Hunter, David J

2013-08-01

The British National Health Service (NHS) is undergoing possibly the most far-reaching set of changes in its sixty-five-year history. While some commentators (like Rudolf Klein) insist that little of substance is likely to change, others consider that the politics of reform may prove quite different on this occasion. The coalition government is committed to restructuring the welfare state and public services and to rolling back the state. The NHS as a popular monopoly public service runs counter to its neoliberal ideology. While (for now) remaining committed to a publicly funded system of health care that is largely free at point of use, the government wishes to encourage much greater diversity in the provision of care, including a much larger role for the for-profit private sector. Despite significant opposition to its proposals, few concessions have been forthcoming, and the legislation that passed onto the statute book in March 2012 remained essentially unchanged. Notwithstanding the lack of convincing evidence, the government is wedded to encouraging greater competition and choice. Thosewho believe the changes will amount to far less than its architects hope for are being too complacent and overlooking the strength of the government's ideological convictions. These threaten to dismantle the NHS and replace it with a more costly, fragmented, and less effective system of care that is driven by profit in place of the public interest.

Episodic Jurassic to Lower Cretaceous intraplate compression in Central Patagonia during Gondwana breakup

Science.gov (United States)

Navarrete, César; Gianni, Guido; Echaurren, Andrés; Kingler, Federico Lince; Folguera, Andrés

2016-12-01

From Lower Jurassic to Lower Cretaceous, several intraplate compression events affected discrete sectors of Central Patagonia, under a general context of crustal extension associated with Gondwana breakup. This was demonstrated by means of 2D and 3D seismic and borehole data, which show partial inversion of Lower and Middle Jurassic extensional structures of the Chubut and Cañadón Asfalto basins, during the earliest stages of breakup. A comparison with surrounding areas in Patagonia, where similar Jurassic intraplate compression was described, allowed the discrimination of three discrete pulses of subtle compression (C1: ∼188-185 Ma; C2: ∼170-163; C3: ∼157-136? Ma). Interestingly, episodic intraplate compressional events are closely followed by high flux magmatic events linked to the westward expansion of the Karoo-Ferrar thermal anomaly, which impacted on the lithosphere of southwest Gondwana in Lower Jurassic. In addition, we determined the approximate direction of the main compressive strain (σ1) compatible with other Jurassic intraplate belts of South America. These observations led us to propose a linkage between a thermo mechanically weakened continental crust due to LIPs activity, changes in plate motions and ridge-push forces generated by the opening of the Weddell Sea, in order to explain intraplate shortening, interrupted while Karoo LIPs magmatic invigoration took place.

Aspects of uranium mineralization in the Beaufort West Karoo

Energy Technology Data Exchange (ETDEWEB)

Pretorius, L E

1977-01-01

The distribution and controlling factors of uranium mineralization in the sedimentary rocks of the Lower Beaufort Group have been investigated in the Beaufort West area between 22/sup 0/O' and 24/sup 0/O'E longitude and 32/sup 0/O' and 32/sup 0/45'S latitude. The mineralization is classified as 'primary' or 'secondary', depending on the time of emplacement and not on the oxidation state of the uranium minerals present. Petrographic and geochemical aspects of primary uranium deposition point to a syngenetic origin. Reconstruction of the paleodepositional environment suggests that the primary mineralization is restricted to paleo-pools or -meander cut-offs where stagnant reducing conditions existed. From geological mapping done to the south of Beaufort West it appears that this uranium mineralization is located in an 'intermediate' paleo-depositional zone between the true fluvial and delta front environments. The indications of secondary uranium distribution and epigenetic concentration in 'rolls' within the area were studied along with various other aspects of such mineralization. The permeability of the arenaceous rocks in the area seems to be too low to host large uranium deposits of this kind. Detail geochemical soil sampling suggests that Zn, P, Co and As could be used as pathfinder elements for uranium. Although regional anomalies were investigated no meaningful pattern could be developed.

Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea.

Science.gov (United States)

Cisneros, Juan Carlos; Abdala, Fernando; Atayman-Güven, Saniye; Rubidge, Bruce S; Şengörc, A M Celâl; Schultz, Cesar L

2012-01-31

The medial Permian (~270-260 Ma: Guadalupian) was a time of important tetrapod faunal changes, in particular reflecting a turnover from pelycosaurian- to therapsid-grade synapsids. Until now, most knowledge on tetrapod distribution during the medial Permian has come from fossils found in the South African Karoo and the Russian Platform, whereas other areas of Pangaea are still poorly known. We present evidence for the presence of a terrestrial carnivorous vertebrate from the Middle Permian of South America based on a complete skull. Pampaphoneus biccai gen. et sp. nov. was a dinocephalian "mammal-like reptile" member of the Anteosauridae, an early therapsid predator clade known only from the Middle Permian of Russia, Kazakhstan, China, and South Africa. The genus is characterized, among other features, by postorbital bosses, short, bulbous postcanines, and strongly recurved canines. Phylogenetic analysis indicates that the Brazilian dinocephalian occupies a middle position within the Anteosauridae, reinforcing the model of a global distribution for therapsids as early as the Guadalupian. The close phylogenetic relationship of the Brazilian species to dinocephalians from South Africa and the Russian Platform suggests a closer faunistic relationship between South America and eastern Europe than previously thought, lending support to a Pangaea B-type continental reconstruction.

Biomass assessment of microbial surface communities by means of hyperspectral remote sensing data.

Science.gov (United States)

Rodríguez-Caballero, Emilio; Paul, Max; Tamm, Alexandra; Caesar, Jennifer; Büdel, Burkhard; Escribano, Paula; Hill, Joachim; Weber, Bettina

2017-05-15

Dryland vegetation developed morphological and physiological strategies to cope with drought. However, as aridity increases, vascular plant coverage gets sparse and microbially-dominated surface communities (MSC), comprising cyanobacteria, algae, lichens and bryophytes together with heterotropic bacteria, archaea and fungi, gain relevance. Nevertheless, the relevance of MSC net primary productivity has only rarely been considered in ecosystem scale studies, and detailed information on their contribution to the total photosynthetic biomass reservoir is largely missing. In this study, we mapped the spatial distribution of two different MSC (biological soil crusts and quartz fields hosting hypolithic crusts) at two different sites within the South African Succulent Karoo (Soebatsfontein and Knersvlakte). Then we characterized both types of MSC in terms of chlorophyll content, and combining these data with the biocrust and quartz field maps, we estimated total biomass values of MSCs and their spatial patterns within the two different ecosystems. Our results revealed that MSC are important vegetation components of the South African Karoo biome, revealing clear differences between the two sites. At Soebatsfontein, MSC occurred as biological soil crusts (biocrusts), which covered about one third of the landscape reaching an overall biomass value of ~480gha -1 of chlorophyll a+b at the landscape scale. In the Knersvlakte, which is characterized by harsher environmental conditions (i.e. higher solar radiation and potential evapotranspiration), MSC occurred as biocrusts, but also formed hypolithic crusts growing on the lower soil-immersed parts of translucent quartz pebbles. Whereas chlorophyll concentrations of biocrusts and hypolithic crusts where insignificantly lower in the Knersvlakte, the overall MSC biomass reservoir was by far larger with ~780gha -1 of chlorophyll a+b. Thus, the complementary microbially-dominated surface communities promoted biomass formation within

Quantum mechanics of Klein-Gordon-type fields and quantum cosmology

International Nuclear Information System (INIS)

Mostafazadeh, Ali

2004-01-01

With a view to address some of the basic problems of quantum cosmology, we formulate the quantum mechanics of the solutions of a Klein-Gordon-type field equation: (∂ t 2 +D)ψ(t)=0, where t is an element of R and D is a positive-definite operator acting in a Hilbert space H-tilde. In particular, we determine all the positive-definite inner products on the space H of the solutions of such an equation and establish their physical equivalence. This specifies the Hilbert space structure of H uniquely. We use a simple realization of the latter to construct the observables of the theory explicitly. The field equation does not fix the choice of a Hamiltonian operator unless it is supplemented by an underlying classical system and a quantization scheme supported by a correspondence principle. In general, there are infinitely many choices for the Hamiltonian each leading to a different notion of time-evolution in H. Among these is a particular choice that generates t-translations in H and identifies t with time whenever D is t-independent. For a t-dependent D, we show that regardless of the choice of the inner product the t-translations do not correspond to unitary evolutions in H, and t cannot be identified with time. We apply these ideas to develop a formulation of quantum cosmology based on the Wheeler-DeWitt equation for a Friedman-Robertson-Walker model coupled to a real scalar field with an arbitrary positive confining potential. In particular, we offer a complete solution of the Hilbert space problem, construct the observables, use a position-like observable to introduce the wave functions of the universe (which differ from the Wheeler-DeWitt fields), reformulate the corresponding quantum theory in terms of the latter, reduce the problem of the identification of time to the determination of a Hamiltonian operator acting in L 2 R+L 2 R, show that the factor-ordering problem is irrelevant for the kinematics of the quantum theory, and propose a formulation of the

Quantum mechanics of Klein-Gordon-type fields and quantum cosmology

Science.gov (United States)

Mostafazadeh, Ali

2004-01-01

With a view to address some of the basic problems of quantum cosmology, we formulate the quantum mechanics of the solutions of a Klein-Gordon-type field equation: (∂t2+D)ψ(t)=0, where t∈R and D is a positive-definite operator acting in a Hilbert space H~. In particular, we determine all the positive-definite inner products on the space H of the solutions of such an equation and establish their physical equivalence. This specifies the Hilbert space structure of H uniquely. We use a simple realization of the latter to construct the observables of the theory explicitly. The field equation does not fix the choice of a Hamiltonian operator unless it is supplemented by an underlying classical system and a quantization scheme supported by a correspondence principle. In general, there are infinitely many choices for the Hamiltonian each leading to a different notion of time-evolution in H. Among these is a particular choice that generates t-translations in H and identifies t with time whenever D is t-independent. For a t-dependent D, we show that regardless of the choice of the inner product the t-translations do not correspond to unitary evolutions in H, and t cannot be identified with time. We apply these ideas to develop a formulation of quantum cosmology based on the Wheeler-DeWitt equation for a Friedman-Robertson-Walker model coupled to a real scalar field with an arbitrary positive confining potential. In particular, we offer a complete solution of the Hilbert space problem, construct the observables, use a position-like observable to introduce the wave functions of the universe (which differ from the Wheeler-DeWitt fields), reformulate the corresponding quantum theory in terms of the latter, reduce the problem of the identification of time to the determination of a Hamiltonian operator acting in L2(R)⊕L2(R), show that the factor-ordering problem is irrelevant for the kinematics of the quantum theory, and propose a formulation of the dynamics. Our method is

[A transference from somewhere else: reevaluation of the controversies between Melanie Klein and Anna Freud (of noise and silence)].

Science.gov (United States)

Prado de Oliveira, L E

1995-01-01

Starting from The Freud-Klein Controversies, the author explores the historical reality of these controversies and their transformations into myth which give them the appearance of titanic fights. The verification of the different periods, the description of the variations in themes and style of intervention of the principal actors of these debates show aspects of the way a psychoanalytic institute works and of the theoretical elaboration in psychoanalysis: these appear very different from what the myth suggests. The major function of myth is, as Freud noted and Strachey reminds us, to hide very trite, even shameful realities. History and myth, theoritical effort and institutional life are all organized from and around transference, a major axis of psychoanalytic thought. When we organize our psychoanalytic lives in societies, we have the pride or the vanity of participating in a great historical movement. This goes back to the work of transference in institutional life that involves primal objects in the crudeness of their sexuality. Such is the constraining strength of transference. Being fully conscious of it, like Stratchey or Balint show us, enables to alleviate its violence and stimulate creativity.

The Relationship Between Carbonatitic, Melilititic and Potassic Trachytic Magma Types at the Saltpeterkop Carbonatite Complex, Sutherland, South Africa

Science.gov (United States)

Janney, P. E.; Marageni, M.

2016-12-01

The 74 Ma Saltpeterkop Carbonatite Complex near Sutherland, South Africa, is unusual in that it is one of the few southern African carbonatites with preserved volcanic features, including a 1 km-diameter tuff ring composed of silicified volcaniclastic breccia. Around the complex, the regionally flat-lying Karoo strata have been dramatically upwarped, with dips away from the Complex as high as 45°. Further, within about a 10 km radius of the center of the complex are hundreds of dikes, sills and diatremes composed mainly of carbonatite, potassic trachyte and olivine melilitite, with the spatial density of these intrusions decreasing with increasing distance. We have recently completed an in-depth geochemical reconnaissance of the Saltpeterkop complex, involving field sampling and whole-rock major and trace element analysis, with radiogenic and stable isotope measurements in progress. While the association with potassic trachytes is relatively common in southern African carbonatites, the presence of significant amounts of primitive olivine melilitite (30-40 wt.% SiO2, Mg# = 61-74) is unusual. Our preliminary model for the origin of the complex involves (1) ascent and intrusion of a mantle-derived carbonated and potassic magma into the mid-to upper crust, (2a) separation of an alkali carbonatite phase from this magma, resulting in intensive local fenitization and partial melting of mid-crustal rocks (thereby forming potassic trachytes), and possibly triggering the initial eruption, (2b) small amounts of primitive, but now less potassic, mantle-derived magma are emplaced as olivine melilitite dikes and diatremes, and (3) differentiation of the mantle-derived magma to generate significant quantities of mainly calcio- and ferro-carbonatite magmas emplaced as dykes and sills.

Basinal analysis of the Ecca and Lowermost Beaufort Beds and associated coal, uranium and heavy mineral beach sand occurrences

International Nuclear Information System (INIS)

Ryan, P.J.; Whitfield, G.G.

1979-01-01

The regional sediment transport directions, major provenance areas and the controlling palaeotectonic and palaeogeographic frameworks of sedimentation have been reconstructed for the Great Karoo Basin during the Permian. Analyses of this magnitude can be useful in regional exploration programmes for coal, uranium and fossil heavy mineral beach sand deposits. The strong palaeogeographic control on coal deposition is demonstrated by the fact that some of the most important deposits accumulated in topographically low lying areas on the pre-Karoo surface. Such areas formed sheltered environments ideal for the growth and accumulation of organic material. Elsewhere relatively slow rates of subsidence of a broad, protected, low lying delta plain controlled the deposition of coal. North of the main Karoo Basin many of the coal deposits are confined to structurally controlled linear basins. Hundreds of sedimentary uranium occurrences of varying grade and size occur within a broad, discontinuous belt in the Lower Beaufort of the southwestern portion of the Karoo Basin. The uranium mineralization occurs in a variety of fluvial deposits usually rich in carbonaceous material. Minute tuffaceous fragments, reflecting contemporaneous vulcanism, form a minor but significant constituent in some of the uraniferous sandstones. The uranium occurrences are confined largely to the Southern and Western Facies of the Lower Beaufort, and occur mainly within the confines of the Karoo Trough. Consolidated heavy mineral beach deposits have been found in the predominantly fluvio-deltaic Middle Ecca Group of the Northern Facies at a number of widely separated locations. These deposits were formed by shore line processes, such as the reworking of delta-front sands, during periods of temporary marine regression

Doliroside A from Dolichos falcata Klein suppressing amyloid β-protein 42 fibrillogenesis: An insight at molecular level.

Directory of Open Access Journals (Sweden)

Dongpu Li

Full Text Available A bioactive chemical constituent, doliroside A, from Chinese traditional herbal medicine Dolichos falcata Klein was isolated, purified and identified by 60% ethanol extraction, thin layer chromatography (TLC, high performance liquid chromatography (HPLC and nuclear magnetic resonance (NMR spectroscopy. Molecular interaction mechanism between doliroside and amyloid β42 protein was evaluated by thioflavin T fluorescence (ThT, circular dichroism (CD, atomic force microscope (AFM, and differential scanning calorimeter (DSC from the aspects of kinetics, secondary structure, morphology, and thermodynamics, respectively. Results show that the purity of doliroside A is 99.9% by HPLC, and its chemical structure is identified by 1H- and 13C-NMR. Doliroside A is observed to be concentration-dependent inhibiting the fibrillation of Aβ42 with the IC50 value of 26.57 ± 1.6 μM. CD and DSC results imply that doliroside A can bind to the nuclei and oligomers of Aβ42 to form a stable complex and suppress Aβ42 fibrillation. AFM images show that doliroside A, after bound to the nuclei and oligomers, redirect Aβ42 into off-pathway, amorphous oligomers. These findings not only provide a full insight into the molecular interaction mechanisms between Aβ42 and doliroside A, but also facilitate the development of new native anti-AD drug of doliroside A compound.

Chitosan mediated enhancement of hydrolysable tannin in Phyllanthus debilis Klein ex Willd via plant cell suspension culture.

Science.gov (United States)

V, Malayaman; N, Sisubalan; R P, Senthilkumar; S, Sheik Mohamed; R, Ranjithkumar; M, Ghouse Basha

2017-11-01

Phyllanthus debilis Klein ex Willd. is wild medicinal plant used in the traditional system of medicine. This plant has been actively used for hepatoprotection and to cure many diseases including jaundice and so on; which leads to complete extinction of this particular species. Therefore, the chitosan mediated cost effective cell suspension method has been developed for the production of hydrolysable tannin. The hydrolysable tannins are the main therapeutically active constituents with antioxidant, anticancer, and antimicrobial properties. An in vitro cell suspension culture was optimized by adding chitosan for production of hydrolysable tannin. According to the growth kinetics, a maximum biomass of 4.46±0.06g fresh cell weight and 1.33±0.04g dry cell weight were obtained from the optimal suspension medium consisted of MS medium+0.5mgL -1 BAP+1.5mgL -1 NAA. Chitosan was treated at the stationary phase which leads to the highest accumulation of hydrolysable tannin compared to the untreated control. Hydrolysable tannin was observed and compared using HPLC at the Rt of 4.91 in both chitosan treated and untreated cells. This is the first ever report where use of chitosan has been done to enhance the production of the hydrolysable tannin in P. debilis using cell suspension culture technique. Copyright © 2017 Elsevier B.V. All rights reserved.

Myrel Chernick and Jennie Klein Eds, The M Word: Real Mothers in Contemporary Art (Toronto: Demeter Press, 2011, 427 pp., ISBN: 978-0986667121, $49.95, paperback.

Directory of Open Access Journals (Sweden)

Natalie Loveless

2013-01-01

Full Text Available As a feminist-mother-artist-theorist writing and making art that reflects on the context of feminist-maternal-art-and-theory today, I have a lot at stake in what one could call the ‘maternal turn.’ This turn is marked by new social media networks, curatorial projects, and recent and upcoming publications that argue for the maternal as a crucial location from which to explore the conditions, ethics, and futures of feminism today. Such turns, of course, are made and not found. Jennie Klein and Meryl Chernick’s 'The M Word: Real Mothers in Contemporary Art', published in May of 2011 by Canada’s Demeter Press, contributes to the making of this maternal turn in contemporary feminist art history, theory and practice today.

Females increase reproductive investment in response to helper-mediated improvements in allo-feeding, nest survival, nestling provisioning and post-fledging survival in the Karoo scrub-robin Cercotrichas coryphaeus

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Lloyd, P.; Andrew, Taylor W.; du Plessis, Morné A.; Martin, T.E.

2009-01-01

In many cooperatively-breeding species, the presence of one or more helpers improves the reproductive performance of the breeding pair receiving help. Helper contributions can take many different forms, including allo-feeding, offspring provisioning, and offspring guarding or defence. Yet, most studies have focussed on single forms of helper contribution, particularly offspring provisioning, and few have evaluated the relative importance of a broader range of helper contributions to group reproductive performance. We examined helper contributions to multiple components of breeding performance in the Karoo scrub-robin Cercotrichas coryphaeus, a facultative cooperative breeder. We also tested a prediction of increased female investment in reproduction when helpers improve conditions for rearing young. Helpers assisted the breeding male in allo-feeding the incubating female, increasing allo-feeding rates. Greater allo-feeding correlated with greater female nest attentiveness during incubation. Nest predation was substantially lower among pairs breeding with a helper, resulting in a 74% increase in the probability of nest survival. Helper contributions to offspring provisioning increased nestling feeding rates, resulting in a reduced incidence of nestling starvation and increased nestling mass. Nestling mass had a strong, positive effect on post-fledging survival. Controlling for female age and habitat effects, annual production of fledged young was 130% greater among pairs breeding with a helper, and was influenced most strongly by helper correlates with nest survival, despite important helper effects on offspring provisioning. Females breeding with a helper increased clutch size, supporting the prediction of increased female investment in reproduction in response to helper benefits. ?? 2009 J. Avian Biol.

Emplacement of inflated Pāhoehoe flows in the Naude's Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement

Science.gov (United States)

Jay, Anne E.; Marsh, Julian S.; Fluteau, Frédéric; Courtillot, Vincent

2018-02-01

Physical volcanological features are presented for a 710-m-thick section, of the Naude's Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are `medial or distal to source' are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source.

A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

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van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

2008-12-01

This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

Expanding radio astronomy in Africa

International Nuclear Information System (INIS)

Gaylard, M J

2013-01-01

The Square Kilometre Array (SKA) Organisation announced in May 2012 that its members had agreed on a dual site solution for the SKA [1]. South Africa's bid for hosting the SKA has caused a ramp up of radio astronomy in Africa. To develop technology towards the SKA, the South African SKA Project (SKA SA) built a protoype radio telescope in 2007, followed in 2010 the seven antenna Karoo Array Telescope (KAT-7). Next is the 64 antenna MeerKAT, which will merge into SKA Phase 1 in Africa. As SKA Phase 2 is intended to add a high resolution capability with baselines out to 3000 km, the SKA SA brought in partner countries in Africa to host outstations. South Africa has been working with the partners to build capacity to operate the SKA and to benefit from it. The SA Department of Science and Technology (DST) developed a proposal to establish radio telescopes in the partner countries to provide hands-on learning and a capability for Very Long Baseline Interferometry (VLBI) research. Redundant 30 m class satellite antennas are being incorporated in this project.

Search for Kaluza-Klein gravitons of the Randall-Sundrum model in the dimuon channel with the D0 detector at Tevatron; Etude de la production de graviton de Kaluza-Klein dans ses desintegrations en paires de muons dans le modele de Randall-Sundrum aupres de l'experience D0 au Tevatron

Energy Technology Data Exchange (ETDEWEB)

Lahrichi, N

2004-07-01

In this thesis we have put the first constraints on the fundamental parameters of the Randall-Sundrum model of extra dimensions, k/M{sub Pl} which is proportional to the coupling of the graviton to the standard model fields and M{sub G} which is the mass of the first excited state of the Kaluza-Klein graviton. The analysis performed on Monte Carlo sample of the signal allowed to find an error in the PYTHIA generator. The elaboration of an independent generator dedicated for this special analysis helped to find out and correct the error. The data sample used for the analysis covers the period running from november 2002 up to july 2003 taken by the D0 collaboration at Tevatron, which corresponds to an accumulated luminosity of 107,8 pb{sup -1}. The search for the graviton in the dimuon channel allowed to measure the Z production cross-section multiplied by the branching ratio in dimuons. (author)

South Korea

International Nuclear Information System (INIS)

Hayes, P.

1990-01-01

South Korea aspires to become a major nuclear supplier in the world nuclear market. There is no doubt that South Korea has great potential to fulfill these aspirations. South Korea is well positioned in terms of competitiveness, market relationships, institutional capability, ability to deliver, and commitment to nonproliferation values. As a mercantilist state, South Korea hopes to capitalize on its close relationships with transnational nuclear corporations in this endeavor. It hopes to participate in two- or three-way joint ventures---especially with the American firms that have traditionally predominated in the South Korean domestic nuclear business---to market their nuclear wares abroad. This paper is divided into four parts. The first section describes South Korea's intent to become a nuclear supplier in the 1990s. It delineates the networks of prior transactions and relationships that South Korea may use to penetrate export markets. The second section reviews South Korea's nuclear export potential, particularly its technological acquisitions from the domestic nuclear program. These capabilities will determine the rate at which South Korea can enter specific nuclear markets. The third section describes the institutional framework in South Korea for the review and approval of nuclear exports

Morphostructural evidence for Recent/active extension in Central Tanzania beyond the southern termination of the Kenya Rift.

Science.gov (United States)

Le Gall, B.; Rolet, J.; Gernigon, L.; Ebinger, C.; Gloaguen, R.

2003-04-01

The southern tip zone of the Kenya Rift on the eastern branch of the East African System is usually thought to occur in the so-called North Tanzanian Divergence. In this region, the narrow (50 km-wide) axial graben of southern Kenya splays southwards, via a major EW-trending volcanic lineament, into a 200 km-wide broad rifted zone with three separate arms of normal faulting and tilted fault blocks (Eyasi, Manyara and Pangani arms from W to E). Remote sensing analysis from Central Tanzania demonstrates that rift morphology exists over an area lying 400 km beyond the southern termination of the Kenya Rift. The most prominent rift structures are observed in the Kilombero region and consist of a 100 km-wide range of uplifted basement blocks fringed to the west by an E-facing half-graben inferred to reach depths of 6-8 km from aeromagnetic dataset. Physiographic features (fault scarps), and river drainage anomalies suggest that the present-day rift pattern in the Kilombero extensional province principally results from Recent/Neogene deformation. That assumption is also supported by the seismogenic character of a number of faults. The Kilombero half-graben is superimposed upon an earlier rift system, Karoo in age, which is totally overprinted and is only evidenced from its sedimentary infill. On the other hand, the nature and thickness of the inferred Neogene synrift section is still unknown. The Kilombero rifted zone is assumed to connect northwards into the central rift arm (Manyara) of the South Kenya Rift via a seismically active transverse fault zone that follows ductile fabrics within the Mozambican crystalline basement. The proposed rift model implies that incipient rifting propagates hroughout the cold and strong crust/lithosphere of Central Tanzania along Proterozoic (N140=B0E) basement weakness zones and earlier Karoo (NS)rift structures. A second belt of Recent-active linked fault/basins also extends further East from the Pangani rift arm to the offshore

23rd May 2011 - University of Liverpool Pro-Vice-Chancellor and Public Orator K. Everest (UK) Mrs Everest in the ATLAS visitor centre with Collaboration Deputy Spokesperson D. Charlton, in LHCb surface building with Collaboration Spokesperson A. Golutvin, accompanied throughout by P. Wells and Liverpool University T. Bowcock and M. Klein.

CERN Multimedia

Maximilen Brice

2011-01-01

23rd May 2011 - University of Liverpool Pro-Vice-Chancellor and Public Orator K. Everest (UK) Mrs Everest in the ATLAS visitor centre with Collaboration Deputy Spokesperson D. Charlton, in LHCb surface building with Collaboration Spokesperson A. Golutvin, accompanied throughout by P. Wells and Liverpool University T. Bowcock and M. Klein.

Growth increments in teeth of Diictodon (Therapsida

Directory of Open Access Journals (Sweden)

J. Francis Thackeray

1991-09-01

Full Text Available Growth increments circa 0.02 mm in width have been observed in sectioned tusks of Diictodon from the Late Permian lower Beaufort succession of the South African Karoo, dated between about 260 and 245 million years ago. Mean growth increments show a decline from relatively high values in the Tropidostoma/Endothiodon Assemblage Zone, to lower values in the Aulacephalodon/Cistecephaluszone, declining still further in the Dicynodon lacerficeps/Whaitsia zone at the end of the Permian. These changes coincide with gradual changes in carbon isotope ratios measured from Diictodon tooth apatite. It is suggested that the decline in growth increments is related to environmental changes associated with a decline in primary production which contributed to the decline in abundance and ultimate extinction of Diictodon.

Lt AW Beauchamp-Proctor – die klein mannet jie met die leeuemoed

African Journals Online (AJOL)

Many millions of words have been written abour heroes and many more will be written in the future, but this article about the late Captain Andrew Weatherby Beauchamp-Proctor, VC., 050., MC.(Bar), OFC., is special because he was the only South African among nineteen pilots to win the Victoria Cross during the First World ...

Beyond rhetoric: South-South collaboration for REDD+

Energy Technology Data Exchange (ETDEWEB)

Nhantumbo, Isilda; MacQueen, Duncan

2011-11-15

Global debates about reducing emissions from deforestation and forest degradation, and promoting conservation, sustainable forest management and enhancement of forest carbon stocks (REDD+) emphasise the need for strategies to build on existing knowledge. In one example of South-South collaboration to do just this, IIED has helped facilitate a Mozambique-Brazil partnership to share expertise and create a unique REDD+ working group. The initiative provides key lessons for other countries contemplating South-South collaboration on REDD+, including the need for charismatic champions, continuity in government representation, and integration across sectors.

The sixth sense in mammalian forerunners: Variability of the parietal foramen and the evolution of the pineal eye in South African Permo-Triassic eutheriodont therapsids

Directory of Open Access Journals (Sweden)

Julien Benoit

2016-12-01

Full Text Available In some extant ectotherms, the third eye (or pineal eye is a photosensitive organ located in the parietal foramen on the midline of the skull roof. The pineal eye sends information regarding exposure to sunlight to the pineal complex, a region of the brain devoted to the regulation of body temperature, reproductive synchrony, and biological rhythms. The parietal foramen is absent in mammals but present in most of the closest extinct relatives of mammals, the Therapsida. A broad ranging survey of the occurrence and size of the parietal foramen in different South African therapsid taxa demonstrates that through time the parietal foramen tends, in a convergent manner, to become smaller and is absent more frequently in eutherocephalians (Akidnognathiidae, Whaitsiidae, and Baurioidea and non-mammaliaform eucynodonts. Among the latter, the Probainognathia, the lineage leading to mammaliaforms, are the only one to achieve the complete loss of the parietal foramen. These results suggest a gradual and convergent loss of the photoreceptive function of the pineal organ and degeneration of the third eye. Given the role of the pineal organ to achieve fine-tuned thermoregulation in ectotherms (i.e., “cold-blooded” vertebrates, the gradual loss of the parietal foramen through time in the Karoo stratigraphic succession may be correlated with the transition from a mesothermic metabolism to a high metabolic rate (endothermy in mammalian ancestry. The appearance in the eye of melanopsin-containing retinal ganglion cells replacing the photoreceptive role of the pineal eye could also have accompanied its loss.

Low thalamic NAA-concentration corresponds to strong neural activation in working memory in Kleine-Levin syndrome.

Science.gov (United States)

Vigren, Patrick; Tisell, Anders; Engström, Maria; Karlsson, Thomas; Leinhard Dahlqvist, Olof; Lundberg, Peter; Landtblom, Anne-Marie

2013-01-01

Kleine Levin Syndrome (KLS) is a rare disorder of periodic hypersomnia and behavioural disturbances in young individuals. It has previously been shown to be associated with disturbances of working memory (WM), which, in turn, was associated with higher activation of the thalamus with increasing WM load, demonstrated with functional magnetic resonance imaging (fMRI). In this study we aimed to further elucidate how these findings are related to the metabolism of the thalamus. fMRI and magnetic resonance spectroscopy were applied while performing a WM task. Standard metabolites were examined: n-acetylaspartate (NAA), myo-inositol, choline, creatine and glutamate-glutamine. Fourteen KLS-patients and 15 healthy controls participated in the study. The patients with active disease were examined in asymptomatic periods. There was a statistically significant negative correlation between thalamic fMRI-activation and thalamic NAA, i.e., high fMRI-activation corresponded to low NAA-levels. This correlation was not seen in healthy controls. Thalamic levels of NAA in patients and controls showed no significant differences between the groups. None of the other metabolites showed any co-variation with fMRI-activation. This study shows negative correlation between NAA-levels and fMRI-activity in the left thalamus of KLS-patients while performing a WM task. This correlation could not be found in healthy control subjects, primarily interpreted as an effect of increased effort in the patient group upon performing the task. It might indicate a disturbance in the neuronal networks responsible for WM in KLS patients, resulting in higher effort at lower WM load, compared with healthy subjects. The general relationship between NAA and BOLD-signal is also discussed in the article.

Tracking Early Jurassic marine (de)oxygenation

Science.gov (United States)

Them, T. R., II; Caruthers, A. H.; Gill, B. C.; Gröcke, D. R.; Marroquín, S. M.; Owens, J. D.

2017-12-01

It has been suggested that the carbon cycle was perturbed during the Toarcian OAE (T-OAE) as observed in the carbon isotope record, and more recently other elemental cycles (e.g., Hg, Mo, Os, S). The most widely accepted hypothesis focuses on the emplacement of the Karoo-Ferrar large igneous province, outgassing of greenhouse gases, and subsequent feedbacks in the Earth system, which caused severe environmental change and biological turnover. Feedbacks to elevated atmospheric pCO2 include enhanced weathering rates, dissociation of methane clathrates, increased terrestrial methanogenesis, and widespread marine anoxia. The sequence of events related to the development and duration of marine anoxia are not well constrained for this time interval due to a lack of open-ocean geochemical records. In order to reconstruct the timing of marine deoxygenation during the Early Jurassic T-OAE, we have utilized thallium isotopes, a novel geochemical proxy from multiple anoxic basins in North America and Germany. Three sites representing a basin transect from the Western Canada Sedimentary Basin, and one site from the South German Basin, were chosen to reconstruct the thallium isotopic composition (ɛ205Tl) of the ocean. The ɛ205Tl composition of sediments deposited under anoxic and euxinic water columns records the global seawater ɛ205Tl composition, a function of the amount of manganese oxides that are precipitated. Increased geographic extent of marine anoxia will cause a decrease in manganese oxide precipitation and perturb the thallium system. Importantly, the inputs of thallium are nearly identical, thus changes in these fluxes cannot drive the observed perturbation. Our new Early Jurassic ɛ205Tl records suggest that the onset of marine deoxygenation occurred concurrently with Karoo-Ferrar magmatism in the late Pliensbachian and continued until after the T-OAE. These new data support a Karoo-Ferrar trigger of the T-OAE. However, thallium isotopes also suggest that

Strides in Preservation of Malawi's Natural Stone

Science.gov (United States)

Kamanga, Tamara; Chisenga, Chikondi; Katonda, Vincent

2017-04-01

The geology of Malawi is broadly grouped into four main lithological units that is the Basement Complex, the Karoo Super group, Tertiary to Quaternary sedimentary deposits and the Chilwa Alkaline province. The basement complex rocks cover much of the country and range in age from late Precambrian to early Paleozoic. They have been affected by three major phases of deformation and metamorphism that is the Irumide, Ubendian and The Pan-African. These rocks comprise gneisses, granulites and schists with associated mafic, ultramafic, syenites and granite rocks. The Karoo System sedimentary rocks range in age from Permian to lower Jurassic and are mainly restricted to two areas in the extreme North and extreme Alkaline Province - late Jurassic to Cretaceous in age, preceded by upper Karoo Dolerite dyke swarms and basaltic lavas, have been intruded into the Basement Complex gneisses of southern Malawi. Malawi is endowed with different types of natural stone deposits most of which remain unexploited and explored. Over twenty quarry operators supply quarry stone for road and building construction in Malawi. Hundreds of artisanal workers continue to supply aggregate stones within and on the outskirts of urban areas. Ornamental stones and granitic dimension stones are also quarried, but in insignificant volumes. In Northern Malawi, there are several granite deposits including the Nyika, which is the largest single outcrop occupying approximately 260.5 km2 , Mtwalo Amazonite an opaque to translucent bluish -green variety of microcline feldspar that occurs in alkali granites and pegmatite, the Ilomba granite (sodalite) occurring in small areas within biotite; apatite, plagioclase and calcite. In the Center, there are the Dzalanyama granites, and the Sani granites. In the South, there are the Mangochi granites. Dolerite and gabbroic rocks spread across the country, treading as black granites. Malawi is also endowed with many deposits of marble. A variety of other igneous