Effects of high temperature on the growth and composition of sugarcane internodes

Sugarcane grown in the Ord River district of Western Australia has lower sucrose content than expected from earlier trials and experience in other irrigated districts. High temperatures have been hypothesised as a possible cause. The effects of high temperature (above 32 degrees C) on growth and carbon partitioning were investigated. A temperature regime of (25-38 degrees C) was compared with (23-33 degrees C). In one experiment, 7-month-old plants of cvv. Q117 and Q158 were subjected to the treatments for 2 months. In another experiment, the plants were allowed to regrow (ratoon) for 6 months. In both experiments, the higher temperature resulted in more, shorter internodes and higher moisture content. Most internodes from plants in the higher temperature treatment had lower sucrose content than internodes from the lower temperature. On a dry mass basis the internodes from the plants in the higher temperature had proportionately more fibre and hexoses but lower sucrose. Combined with an increased number of nodes in a stem of similar or shorter length this would result in higher stalk fibre and lower sucrose content. The data provided evidence that sugarcane partitions less carbon to stored sucrose when grown under high compared with low temperatures. The two cultivars partitioned carbon between soluble (sugars) and insoluble (fibre) fractions to different degrees. These experiments also indicate that the current models describing leaf appearance and perhaps sugarcane growth at temperatures above 32 degrees C, in general, need revision.

Short- and long-term consequences of thermal variation in the larval environment of anurans

To survive adverse or unpredictable conditions in the ontogenetic environment, many organisms retain a level of phenotypic plasticity that allows them to meet the challenges of rapidly changing conditions. Larval anurans are widely known for their ability to modify behaviour, morphology and physiological processes during development, making them an ideal model system for studies of environmental effects on phenotypic traits. Although temperature is one of the most important factors influencing the growth, development and metamorphic condition of larval anurans, many studies have failed to include ecologically relevant thermal fluctuations among their treatments. We compared the growth and age at metamorphosis of striped marsh frogs Limnodynastes peronii raised in a diurnally fluctuating thermal regime and a stable regime of the same mean temperature. We then assessed the long-term effects of the larval environment on the morphology and performance of post-metamorphic frogs. Larval L. peronii from the fluctuating treatment were significantly longer throughout development and metamorphosed about 5 days earlier. Frogs from the fluctuating group metamorphosed at a smaller mass and in poorer condition compared with the stable group, and had proportionally shorter legs. Frogs from the fluctuating group showed greater jumping performance at metamorphosis and less degradation in performance during a 10-week dormancy. Treatment differences in performance could not be explained by whole-animal morphological variation, suggesting improved contractile properties of the muscles in the fluctuating group.

Three-body recombination of ultracold Bose gases using the truncated Wigner method

We apply the truncated Wigner method to the process of three-body recombination in ultracold Bose gases. We find that within the validity regime of the Wigner truncation for two-body scattering, three-body recombination can be treated using a set of coupled stochastic differential equations that include diffusion terms, and can be simulated using known numerical methods. As an example we investigate the behavior of a simple homogeneous Bose gas, finding a very slight increase of the loss rate compared to that obtained by using the standard method.

Determining the contribution of technical change, efficiency change and scale change to productivity growth in the privatized English and Welsh water and sewerage industry:1985-2000

The water and sewerage industry of England and Wales was privatized in 1989 and subjected to a new regime of environmental, water quality and RPI+K price cap regulation. This paper estimates a quality-adjusted input distance function, with stochastic frontier techniques in order to estimate productivity growth rates for the period 1985-2000. Productivity is decomposed so as to account for the impact of technical change, efficiency change, and scale change. Compared with earlier studies by Saal and Parker [(2000) Managerial Decision Econ 21(6):253-268, (2001) J Regul Econ 20(1): 61-90], these estimates allow a more careful consideration of how and whether privatization and the new regulatory regime affected productivity growth in the industry. Strikingly, they suggest that while technical change improved after privatization, productivity growth did not improve, and this was attributable to efficiency losses as firms appear to have struggled to keep up with technical advances after privatization. Moreover, the results also suggest that the excessive scale of the WaSCs contributed negatively to productivity growth. © 2007 Springer Science+Business Media, LLC.

The significance of hand wash compliance on the transfer of dermal lipids in contact lens wear

Aim: The aim of this study was to assess the impact of hand washing regimes on lipid transference to contact lenses. The presence of lipids on contact lenses can affect visual acuity and enhance spoilation. Additionally, they may even mediate and foster microbial transfer and serve as a marker of potential dermal contamination. Methods and materials: A social hand wash and the Royal College of Nursing (RCN) hand wash were investigated. A 'no-wash regime' was used as control. The transfer of lipids from the hand was assessed by Thin Layer Chromatography (TLC). Lipid transference to the contact lenses was studied through fluorescence spectroscopy (FS). Results: Iodine staining, for presence of lipids, on TLC plates indicated the 'no-wash regime' score averaged at 3.4 ± 0.8, the social wash averaged at 2.2 ± 0.9 and the RCN averaged at 1.2 ± 0.3 on a scale of 1-4. The FS of lipids on contact lenses for 'no washing' presented an average of 28.47 ± 10.54 fluorescence units (FU), the social wash presented an average of 13.52 ± 11.12. FU and the RCN wash presented a much lower average 6.47 ± 4.26. FU. Conclusions: This work demonstrates how the method used for washing the hands can affect the concentration of lipids, and the transfer of these lipids onto contact lenses. A regime of hand washing for contact lens users should be standardised to help reduce potentially transferable species present on the hands. © 2011 British Contact Lens Association.

Numerical modelling of dispersion managed soliton transmission

This thesis presents the results of numerical modelling of the propagation of dispersion managed solitons. The theory of optical pulse propagation in single mode optical fibre is introduced specifically looking at the use of optical solitons for fibre communications. The numerical technique used to solve the nonlinear Schrödinger equation is also introduced. The recent developments in the use of dispersion managed solitons are reviewed before the numerical results are presented. The work in this thesis covers two main areas; (i) the use of a saturable absorber to control the propagation of dispersion managed solutions and (ii) the upgrade of the installed standard fibre network to higher data rates through the use of solitons and dispersion management. Saturable absorbe can be used to suppress the build up of noise and dispersive radiation in soliton transmission lines. The use of saturable absorbers in conjunction with dispersion management has been investigated both as a single pulse and for the transmission of a 10Gbit/s data pattern. It is found that this system supports a new regime of stable soliton pulses with significantly increased powers. The upgrade of the installed standard fibre network to higher data rates through the use of fibre amplifiers and dispersion management is of increasing interest. In this thesis the propagation of data at both 10Gbit/s and 40Gbit/s is studied. Propagation over transoceanic distances is shown to be possible for 10Gbit/s transmission and for more than 2000km at 40Gbit/s. The contribution of dispersion managed solitons in the future of optical communications is discussed in the thesis conclusions.

Mechanical properties of sheet metal under forming conditions

In the bulge test, a sheet metal specimen is clamped over a circular hole in a die and formed into a bulge by the hydraulic pressure on one side of the specirnen. As the unsupported part of the specimen is deformed in this way, its area is increased, in other words, the material is generally stretched and its thickness generally decreased. The stresses causing this stretching action are the membrane stresses in the shell generated by the hydraulic pressure, in the same way as the rubber in a toy balloon is stretched by the membrane stresses caused by the air inside it. The bulge test is a widely used sheet metal test, to determine the "formability" of sheet materials. Research on this forming process (2)-(15)* has hitherto been almost exclusively confined to predicting the behaviour of the bulged specimen through the constitutive equations (stresses and strains in relation to displacements and shapes) and empirical work hardening characteristics of the material as determined in the tension test. In the present study the approach is reversed; the stresses and strains in the specimen are measured and determined from the geometry of the deformed shell. Thus, the bulge test can be used for determining the stress-strain relationship in the material under actual conditions in sheet metal forming processes. When sheet materials are formed by fluid pressure, the work-piece assumes an approximately spherical shape, The exact nature and magnitude of the deviation from the perfect sphere can be defined and measured by an index called prolateness. The distribution of prolateness throughout the workpiece at any particular stage of the forming process is of fundamental significance, because it determines the variation of the stress ratio on which the mode of deformation depends. It is found. that, before the process becomes unstable in sheet metal, the workpiece is exactly spherical only at the pole and at an annular ring. Between the pole and this annular ring the workpiece is more pointed than a sphere, and outside this ring, it is flatter than a sphere. In the forming of sheet materials, the stresses and hence the incremental strains, are closely related to the curvatures of the workpiece. This relationship between geometry and state of stress can be formulated quantitatively through prolateness. The determination of the magnitudes of prolateness, however, requires special techniques. The success of the experimental work is due to the technique of measuring the profile inclination of the meridional section very accurately. A travelling microscope, workshop protractor and surface plate are used for measurements of circumferential and meridional tangential strains. The curvatures can be calculated from geometry. If, however, the shape of the workpiece is expressed in terms of the current radial (r) and axial ( L) coordinates, it is very difficult to calculate the curvatures within an adequate degree of accuracy, owing to the double differentiation involved. In this project, a first differentiation is, in effect, by-passed by measuring the profile inclination directly and the second differentiation is performed in a round-about way, as explained in later chapters. The variations of the stresses in the workpiece thus observed have not, to the knowledge of the author, been reported experimentally. The static strength of shells to withstand fluid pressure and their buckling strength under concentrated loads, both depend on the distribution of the thickness. Thickness distribution can be controlled to a limited extent by changing the work hardening characteristics of the work material and by imposing constraints. A technique is provided in this thesis for determining accurately the stress distribution, on which the strains associated with thinning depend. Whether a problem of controlled thickness distribution is tackled by theory, or by experiments, or by both combined, the analysis in this thesis supplies the theoretical framework and some useful experimental techniques for the research applied to particular problems. The improvement of formability by allowing draw-in can also be analysed with the same theoretical and experimental techniques. Results on stress-strain relationships are usually represented by single stress-strain curves plotted either between one stress and one strain (as in the tension or compression tests) or between the effective stress and effective strain, as in tests on tubular specimens under combined tension, torsion and internal pressure. In this study, the triaxial stresses and strains are plotted simultaneously in triangular coordinates. Thus, both stress and strain are represented by vectors and the relationship between them by the relationship between two vector functions. From the results so obtained, conclusions are drawn on both the behaviour and the properties of the material in the bulge test. The stress ratios are generally equal to the strain-rate ratios (stress vectors collinear with incremental strain vectors) and the work-hardening characteristics, which apply only to the particular strain paths are deduced. Plastic instability of the material is generally considered to have been reached when the oil pressure has attained its maximum value so that further deformation occurs under a constant or lower pressure. It is found that the instability regime of deformation has already occurred long before the maximum pressure is attained. Thus, a new concept of instability is proposed, and for this criterion, instability can occur for any type of pressure growth curves.

The development of an in vivo model of drug-induced terminal differentiation of Leukaemic cells

The technique of growing human leukaemic cells in diffusion chambers was developed to enable chemicals to be assessed for their ability to induce terminal differentiation. HL-60 promyelocytic leukaemia cell growth, in a lucite chamber with a Millipore filter, was optimised by use of a lateral incision site. Chambers were constructed using 0.45um filters and contained 150ul of serum-free HL-60 cells at a density of 1x106 cells/ml. The chambers were implanted into CBA/Ca mice and spontaneous terminal differentiation of the cells to granulocytes was prevented by the use of serum-free medium. Under these conditions there was an initial growth lag of 72 hours and a logarithmic phase of growth for 96 hours; the cell number reached a plateau after 168 hours of culture in vivo. The amount of drug in the plasma of the animal and in chambers that had been implanted for 5 days, was determined after a single ip injection of equitoxic doses of N-methylformamide, N-ethylformamide, tetramethylurea, N-dibutylformamide, N-tetramethylbutylformamide and hexamethylenebisacetamide. Concentrations of both TMU and HMBA were obtained in the plasma and in the chamber which were pharmacologically effective for the induction of differentiation of HL-60 cells in vitro, that is 12mM TMU and 5mM HMBA. A 4 day regime of treatment of animals implanted with chambers demonstrated that TMU and HMBA induced terminal differentiation of 50% and 35%, respectively, of the implanted HL-60 cells to granulocyte-like cells, assessed by measurement of functional and biochemical markers of maturity. None of the other agents attained concentrations in the plasma that were pharmacologically effective for the induction of differentiation of the cells in vitro and were unable to induce the terminal differentiation of the cells in vivo.

The performance of stabilized and unstabilized minestone in an aqueous environment with emphasis on its erosion resistance

Britain's sea and flood defences are becoming increasingly aged and as a consequence, more fragile and vulnerable. As the government's philosophy on resources shifts against the use of prime quarried and dredged geo-materials, the need to find alternative bulk materials to bolster Britain's prone defences becomes more pressing. One conceivable source for such a material is colliery waste or minestone. Although a plethora of erosion-abrasion studies have been carried out on soils and soil-cements, very little research has been undertaken to determine the resistance of minestone and its cement stabilized form to the effects of water erosion. The thesis reviews the current extent to which soil-cements, minestone and cement stabilized minestone (CSM) have been employed for hydraulic construction projects. A synopsis is also given on the effects of immersion on shales, mudstones and minestone, especially with regard to the phenomena of slaking. A laboratory study was undertaken featuring a selection of minestones from several British coalfields. The stability of minestone and CSM in sea water and distilled water was assessed using slaking tests and immersion monitoring and the bearing on the use of these materials for hydraulic construction is discussed. Following a review of current erosion apparatus, the erosion/abrasion test and rotating cylinder device were chosen and employed to assess the erosion resistance of minestone and CSM. Comparison was made with a sand mix designed to represent a dredged sand, the more traditional, bulk hydraulic construction material. The results of the erosion study suggest that both minestone and CSM were more resistant to erosion and abrasion than equivalently treated sand mixes. The greater resistance of minestone to the agents of erosion and abrasion is attributed to several factors including the size of the particles, a greater degree of cement bonding and the ability of the minestone aggregate to absorb, rather than transmit shock waves produced by impacting abrasive particles. Although minestone is shown to be highly unstable when subjected to cyclic changes in its moisture content, the study suggests that even in an intertidal regime where cyclic immersion does takes place, minestone will retain sufficient moisture within its fabric to prevent slaking from taking place. The slaking study reveals a close relationship between slaking susceptibility and total pore surface area as revealed by porosimetry. The immersion study shows that although the fabric of CSM is rapidly attacked in sea water, a high degree of the disruption is associated with the edges and corners of samples (ie. free surface) while the integrity of the internal fabric remains relatively intact. CSM samples were shown to be resilient when subjected to immersion in distilled water. An overall assessment of minestone and CSM would suggest that with the implementation of judicious selection and appropriate quality control they could be used as alternative materials for flood and sea defences. It is believed, that even in the harsh regime of a marine environment, CSM could be employed for temporary and sacrificial schemes.

Fiber-type transitions and satellite cell activation in low-frequency-stimulated muscles of young and aging rats

We examined satellite cell content and the activity of satellite cell progeny in tibialis anterior muscles of young (15 weeks) and aging (101 weeks) Brown Norway (BN) rats, after they were exposed for 50 days to a standardized and highly reproducible regime of chronic low-frequency electrical stimulation. Chronic low-frequency electrical stimulation was successful in inducing fast-to-slow fiber-type transformation, characterized by a 2.3-fold increase in the proportion of IIA fibers and fourfold and sevenfold decreases in the proportion of IID/X and IIB fibers in both young and aging BN rats. These changes were accompanied by a twofold increase in the satellite cell content in both the young and aging groups; satellite cell content reached a level that was significantly higher in the young group (p < .04). The total muscle precursor cell content (i.e., satellite cells plus progeny), however, did not differ between groups, because there was a greater number of satellite cell progeny passing through the proliferative and differentiative compartments of the aging group. The resulting 1.5-fold increase in myonuclear content was similar in the young and aging groups. We conclude that satellite cells and satellite cell progeny of aging BN rats possess an unaltered capacity to contribute to the adaptive response.

Exact solution for the energy spectrum of Kelvin-wave turbulence in superfluids

We study the statistical and dynamical behavior of turbulent Kelvin waves propagating on quantized vortices in superfluids and address the controversy concerning the energy spectrum that is associated with these excitations. Finding the correct energy spectrum is important because Kelvin waves play a major role in the dissipation of energy in superfluid turbulence at near-zero temperatures. In this paper, we show analytically that the solution proposed by [L’vov and Nazarenko, JETP Lett. 91, 428 (2010)] enjoys existence, uniqueness, and regularity of the prefactor. Furthermore, we present numerical results of the dynamical equation that describes to leading order the nonlocal regime of the Kelvin-wave dynamics. We compare our findings with the analytical results from the proposed local and nonlocal theories for Kelvin-wave dynamics and show an agreement with the nonlocal predictions. Accordingly, the spectrum proposed by L’vov and Nazarenko should be used in future theories of quantum turbulence. Finally, for weaker wave forcing we observe an intermittent behavior of the wave spectrum with a fluctuating dissipative scale, which we interpreted as a finite-size effect characteristic of mesoscopic wave turbulence.

Kiigazítás recesszió nélkül. Esettanulmány a magyar stabilizációról = Adjustment without recession: A Case Study of Hungarian Stabilization

1995. március 12-én a magyar kormány és a központi bank szigorú kiigazítási és stabilizációs programot hirdetett meg. A cikk az első eredmények számbavételére tesz kísérletet. A program meghirdetése előtt Magyarország két egymást követő év- ben hatalmas fizetésimérleg-hiányt mutatott fel, és nemzetközi megítélése romlani kezdett. A program radikális intézkedései nyomán elkerülhetővé vált a mexikói vál- sághoz hasonló pénzügyi katasztrófa. Sok makrogazdasági mutató jól érzékelhető javulást jelez: lényegesen csökkent a kereskedelmi mérleg és a folyó fizetési mérleg hiánya, a költségvetés elsődleges egyenlege pozitív lett. Az ilyesféle stabilizációs programokat rendszerint súlyos visszaesés és a munkanélküliség nagy növekedése kíséri. Magyarország elkerülte ezeket a mellékhatásokat: a GDP drasztikus vissza- esés helyett valamelyest tovább növekedett, és a munkanélküliség változatlan ma- radt. A javulásnak nagy ára volt: az életszínvonal erőteljes csökkenése, az infláció felgyorsulása, bár a magyarországi infláció még mindig a kézben tartott, mérsékelt infláció sávjában maradt. A cikk ismerteti a program heterodox módszereit: 1. nagy leértékelés, az előre meghirdetett csúszó árfolyam rezsimjének bevezetése, valamint ideiglenes import- vámpótlék kivetése; 2. határozott jövedelempolitika, amely 12 százalékos reálbércsök- kenést kényszerített ki; 3. fiskális intézkedések, köztük jóléti jogosultságok csök- kentése (a program meghirdetése előtt ezek a jogosultságok tabuk voltak); 4. a hitel- kínálat átcsoportosítása a vállalati szektor javára, a jövedelmezőség növekedése; 5. feszített (bár nem mértéktelenül feszített) monetáris politika, amely lehetővé tette a sikeres vállalatok expanzióját; 6. a privatizáció felgyorsítása, nagy és sikeres lépé- sek egyes kulcsszektorok (energia, telekommunikáció) privatizációjában. Végezetül a tanulmány óva int a túlzott magabiztosságtól és felhívja a figyelmet a potenciális veszélyekre. A makrogazdasági javulás még törékeny. A magyar fejlődés legbiztatóbb sajátossága a termelékenység erőteljes és folyamatos növekedése. / === / On March 12, 1995 Hungary s government and central bank announced a tough program of adjustment and stabilization. This study is an attempt to asses the first results. Before the announcement of the program Hungary had a huge current account deficit for two consecutive years, and her international reputation started to decline. The program s radical measures made it possible to avoid a Mexico-style financial catastrophe. Many macroeconomic indicators show tangible improvement: the trade deficit and the deficit on the current account have been reduced significantly, the primary budget shifted to surplus. These kinds of adjustment programs are usually associated with deep recession and a large increase of unemployment. Hungary avoided these adverse side-effects: GDP instead of a drastic decline, continued to grow somewhat, and unemployment remained unchanged. There was a high price for the improvement: a sharp decline in the standard of living, and an acceleration of inflation, although Hungary is still in the range of controlled, moderate inflation. The paper describes the heterodox instruments of the program: (1) large devaluation, followed by a new exchange rate regime of pre-announced crawling peg, and a temporary import surcharge, (2) energetic income policy, enforcing a 12% cut in real wages; (3) fiscal measures, including cuts in welfare entitlements. That happened for the first time: before the program entitlements had been regarded as taboo ; (4) reallocation of credit supply in favor of the enterprise sector; increase of profitability; (5) tight (but not excessively tight) monetary policy, allowing the expansion of successful private busi- ness; (6) acceleration of privatisation, including large and successful steps in the privatisation of some key sectors (energy, telecommunication). Finally the paper warns against excessive self- confidence and draws the attention to potential dangers. The macroeconomic improvement is still fragile. The most reassuring feature of Hungary s development is the impressive and persistent improvement of productivity.

Radiogenic isotope record of Arctic Ocean circulation and weathering inputs of the past 15 million years

Lead (Pb), neodymium (Nd), and strontium (Sr) isotopic analyses were carried out on sediment leachates (reflecting the isotope composition of past seawater) and digests of the bulk residues (reflecting detrital continental inputs) of Integrated Ocean Drilling Program (IODP) Leg 302 and core PS2185 from the Lomonosov Ridge (Arctic Ocean). Our records are interpreted to reflect changes in continental erosion and oceanic circulation, driven predominantly by tectonic forcing on million-year timescales in the older (pre-2 Ma) part of the record and by climatic forcing of weathering and erosion of the Eurasian continental margin on thousand-year timescales in the younger (post-2 Ma) part. These data, covering the past ~15 Ma, show that continental inputs to the central Arctic Ocean have been more closely linked to glacial and hydrological processes occurring on the Eurasian margin than on continental North America and Greenland. The constancy of the detrital input signatures supports the early existence of an Arctic sea ice cover, whereas the major initiation of Northern Hemisphere glaciation at 2.7 Ma appears to have had little impact on the weathering regime of the Eurasian continental margin.

Regime jurídico dos incentivos fiscais: uma análise à luz da ordem econômica

This scientific investigation begins with the recognition of the authorization granted by the Constitutional Legislator to the State for, relativizing its neutrality towards the private sector, intervene in the behavior of economic agents, through different means, including fiscal incentives and tax increases in order to achieve the objectives and directives of the Federal Constitution, as well as achieve the rights and guarantees also described in the Federal Constitution. Demonstrates, however, that this intervention in the private sector has the power to generate both salutary reflections as perverse and divorced goals from what was established by the Federal Constitution and Multilateral Agreements and this is the basis that justifies the relevance of the study: because of the urgency to provide a thorough analysis of the phenomenon of state intervention in the Economic Order, given the importance of its impacts, both for citizens' lives, as well as for the maintenance of the State established as it is nowadays. From this premise, this research examines the issue of tax policies adopted in the country, focusing on tax incentives, comparing its use with the principles of the Economic Order and the General Agreement on Tariffs and Trade - GATT analyzing whether these have been respected or if Brazil adopted unjustified protectionist measures. From this context, this research approximated different branches of the law, developed through literature review in areas such as constitutional law, economic law, tax law, financial law and law and economics. This study verifies the motivations and objectives that underlie the adopted justifications for the use of tax incentives, as well as its results, seeking to empirically answer if its use is reasonable and consistent with the terms enshrined in the Federal Constitution of 1988 and GATT. The answer to this research question will be sought through doctrinal analysis, jurisprudence and hard cases. Thus, the study begins with the historical evolution of extrafiscality, analyzes the principles that should guide the behavior of economic agents. Subsequently analyzes the legal regime of tax incentives and the results achieved by hard cases in which the tax policies with extrafiscal nature were adopted in order to demonstrate the positive and negative consequences arising from the adoption of this type of benefit

Annotated record of the detailed examination of Mn deposits from COCOTOW Expedition stations in the intersection of the Siqueiros Transform Fault and the East Pacific Rise

A near-bottom geological and geophysical survey was conducted at the western intersection of the Siqueiros Transform Fault and the East Pacific Rise. Transform-fault shear appears to distort the east flank of the rise crest in an area north of the fracture zone. In ward-facing scarps trend 335° and do not parallel the regional axis of spreading. Small-scale scarps reveal a hummocky bathymetry. The center of spreading is not a central peak but rather a 20-40 m deep, 1 km wide valley superimposed upon an 8 km wide ridge-crest horst. Small-scale topography indicates widespread volcanic flows within the valley. Two 0.75 km wide blocks flank the central valley. Fault scarps are more dominant on the western flank. Their alignment shifts from directions intermediate to parallel to the regional axis of spreading (355°). A median ridge within the fracture zone has a fault-block topography similar to that of the East Pacific Rise to the north. Dominant eastward-facing scarps trending 335° are on the west flank. A central depression, 1 km wide and 30 m deep, separates the dominantly fault-block regime of the west from the smoother topography of the east flank. This ridge originated by uplift due to faulting as well as by volcanism. Detailed mapping was concentrated in a perched basin (Dante's Hole) at the intersection of the rise crest and the fracture zone. Structural features suggest that Dante's Hole is an area subject to extreme shear and tensional drag resulting from transition between non-rigid and rigid crustal behavior. Normal E-W crustal spreading is probably taking place well within the northern confines of the basin. Possible residual spreading of this isolated rise crest coupled with shear drag within the transform fault could explain the structural isolation of Dante's Hole from the remainder of the Siqueiros Transform Fault.