Entire Trace Research Articles

Watershed reconstruction of a Paleocene-Eocene lake basin using Sr isotopes in carbonate rocks

Provenance studies have used Sr isotopes ( 87 Sr/ 86 Sr) of silicate source rocks as a link to their eroded basinal equivalents. This technique, however, cannot identify the proportional inputs from different watersheds or define more precisely sedimentation events due to tectonic or climatic change. Erosion of carbonate rocks dominates the Sr input within basin drainage and potentially can be used through 87 Sr/ 86 Sr ratios to reconstruct paleohydrology of the entire basin and trace watershed inputs and depositional patterns in continental basins. The Sr isotopic ratios from waters of the source area, allowing for the mixing of shallow groundwater and surface water along the transport path, are homogenized in the basinal carbonate sediments. Mineralogy and diagenesis of carbonate rocks generally do not affect the Sr isotopic signal in a near-surface system lacking external influence by volcanism, eolian dust, or deep geothermal waters. The 87 Sr/ 86 Sr ratios from the source area are directly comparable to those in the receiving continental basin. The Sr isotopic signal of the Paleocene–Eocene Flagstaff Formation (central Utah), a carbonate lake deposit in a foreland basin, is compared to that of projected source waters draining its thrust front, the Sevier fold-thrust belt. Freshwater carbonates compose a large portion of the lowermost Ferron Mountain and uppermost Musinia Peak Members of the formation, whereas gypsum and carbonates predominate in the middle Cove Mountain Member. Previous research had attributed gypsum deposition to the deposition of the middle Cove Mountain Member to either climatic change or unroofing of diapirs of Jurassic gypsiferous carbonates. To examine more closely the influence of climate versus tectonics on Flagstaff sedimentation as well as the efficacy of provenance studies using carbonates, we collected rock samples from the three members of the formation on the Wasatch Plateau of central Utah in addition to sampling stream water associated with Pennsylvanian–Permian and Jurassic carbonate terrains from the nearby thrust front. The 87 Sr/ 86 Sr ratios in carbonates and gyprock belonging to the Flagstaff Formation remained unchanged during deposition, the average Sr isotope composition of the Flagstaff rocks being identical to that of sampled waters draining the projected provenance area. There was little change in source rock weathering as the thrust front evolved. Deposition of gypsum occurred in the basinal lake only during the deposition of the middle Cove Mountain Member, despite its constant exposure in the drainage area, suggesting a changing balance of tectonic and climatic controls during lake sedimentation. The 87 Sr/ 86 Sr isotopic studies targeting carbonate rocks and their presumed source waters are a simple but accurate method for reconstructing the paleohydrology of lake basins.

Measurement and Analysis of Postsynaptic Potentials Using a Novel Voltage-Deconvolution Method

Accurate measurement of postsynaptic potential amplitudes is a central requirement for the quantification of synaptic strength, dynamics of short-term and long-term plasticity, and vesicle-release statistics. However, the intracellular voltage is a filtered version of the underlying synaptic signal and so a method of accounting for the distortion caused by overlapping postsynaptic potentials must be used. Here a voltage-deconvolution technique is demonstrated that defilters the entire voltage trace to reveal an underlying signal of well-separated synaptic events. These isolated events can be cropped out and reconvolved to yield a set of isolated postsynaptic potentials from which voltage amplitudes may be measured directly-greatly simplifying this common task. The method also has the significant advantage of providing a higher temporal resolution of the dynamics of the underlying synaptic signal. The versatility of the method is demonstrated by a variety of experimental examples, including excitatory and inhibitory connections to neurons with passive membranes and those with activated voltage-gated currents. The deconvolved current-clamp voltage has many features in common with voltage-clamp current measurements. These similarities are analyzed using cable theory and a multicompartment cell reconstruction, as well as direct comparison to voltage-clamp experiments.

Multiple attenuation using eigenvalue decomposition

Multiple reflections constitute one of the most troublesome forms of coherent noise in seismic exploration, especially in marine surveys. There are many approaches to attenuating or suppressing multiples, but none can remove all multiple reflections under all conditions. We have eveloped two new methods to attenuate multiple reflections using the Karhunen-Loeve transform which extract coherent information from multichannel input data in a least-squares sense. They supplement conventional methods. The first is the ‘localized multiple attenuation' method. Its aim is to attenuate a single (typically water bottom) multiple reflection in deep water or multisource marine acquisition. It is similar to velocity filter methods but is not as prone to spatial aliasing and edge effects. The criterion of local coherency gives the method the flexibility to discriminate between primary and multiple reflections. The second is the ‘targeted multiple attenuation' method. It uses the similarity between a primary reflection and its multiple in both the spatial and time directions. Its aim is to remove a particular multiple reflection associated with a specified primary rather than all the multiple energy for an entire trace. The method can be applied pre- or post-stack, and to 2D or 3D data. Keywords : multiple, reflection, suppression, eigenvector, eigenvalue Global Journal of Pure and Applied Sciences Vol. 12(2) 2006: 225-227

An Improved Method to Estimate Empirical System Parallel Resonant Frequencies Using Capacitor Switching Transient Data

This paper presents an improved technique for estimating system parallel resonant frequencies using capacitor switching transient data. Unlike the previous method where the resonant frequency is estimated using the entire waveform trace, the proposed method removes undesired background harmonic distortions and uses only the effective transient part of the disturbance waveform. As such, the proposed method can be applied to data taken from any measurement point including a customer facility with significant nonlinear loads.

Checking and Correcting Behaviors of Java Programs at Runtime with Java-MOP

Monitoring-oriented programming (MOP) is a software development and analysis technique in which monitoring plays a fundamental role. MOP users can add their favorite or domain-specific requirements specification formalisms into the framework by means of logic plug-ins, which essentially comprise monitor synthesis algorithms for properties expressed as formulae. The properties are specified together with declarations stating where and how to automatically integrate the corresponding monitor into the system, as well as what to do if the property is violated or validated. In this paper we present Java-MOP, an MOP environment for developing robust Java applications. Based upon a carefully designed specification schema and upon several logic plug-ins, Java-MOP allows users to specify and monitor properties which can refer not only to the current program state, but also to the entire execution trace of a program, including past and future behaviors.

Surface-consistent deconvolution using reciprocity and waveform inversion

Source and receiver responses must be equalized when their behavior or coupling changes with location within a given survey. Existing surface-consistent deconvolution techniques that account for these effects assume that common-midpoint (CMP) gathering is valid — the seismic trace is decomposed into a source function, a receiver response, a normal-incidence reflectivity term, and an offset-related component that is laterally shift invariant. As a result, the performance of existing surface-consistent deconvolution techniques is best when applied to primary reflection data only, since the offset dependency of ground roll and multiples varies laterally in media with lateral variations. We have developed an alternative method for surface-consistent deconvolution that is applicable to the entire seismic trace and is therefore essentially a raw-data preprocessing step. The method is based on reciprocity of the medium response. Assuming that conditions for applicability of reciprocity are met, we can attribute differences between normal and reciprocal recordings to the source and receiver perturbations. Contrary to existing surface-consistent deconvolution methods, this approach uses the full description of the wavefield and is therefore ideally suited for prestack processing. We have applied this technique to single-sensor data acquired in Manistee County, Michigan. At this site, near-surface conditions vary, and this significantly affects data quality. The application of the new deconvolution procedure substantially improves S/N ratio on both prestack and poststack data, and these results compare favorably to those obtained using existing surface-consistent deconvolution techniques, since they require subjective data scaling to obtain acceptable results. The obtained source corrections are correlated to changes in near-surface conditions — in this case, to changes in water-saturation levels. We do not observe such a correlation for the receiver corrections, which vary rapidly along the spread. Finally, the receiver response does not agree with the generally accepted damped harmonic oscillator model. For frequencies below 100 Hz, the retrieved receiver variations are larger than predicted by this model, and we cannot explain the receiver response using a single resonant frequency for the geophone-ground coupling.

A measurement-analytic approach for QoS estimation in a network based on the dominant time scale

In this paper, we describe a measurement-analytic approach for estimating the overflow probability, an important measure of the quality of service (QoS), at a given multiplexing point in the network. A multiplexing point in the network could be a multiplexer or an output port of a switch or router where resources such as bandwidth and buffers are shared. Our approach impinges on using the notion of the dominant time scale (DTS), which corresponds to the most probable time scale over which overflow occurs. The DTS provides us with a measurement window for the statistics of the traffic, but is in fact itself defined in terms of the statistics of the traffic over all time. This, in essence, results in a chicken-and-egg type of unresolved problem. For the DTS to be useful for on-line measurements, we need to be able to break this chicken-and-egg cycle, and to estimate the DTS with only a bounded window of time over which the statistics of the traffic are to be measured. In this paper, we present a stopping criterion to successfully break this cycle and find a bound on the DTS. Thus, the result has significant implications for network measurements. Our approach is quite different from other works in the literature that require off-line measurements of the entire trace of the traffic. In our case, we need to measure only the statistics of the traffic up to a bound on the DTS. We also investigate the characteristics of this upper bound on the DTS, and provide numerical results to illustrate the utility of our measurement analytic approach.

The Titri Fault System: Quaternary‐active faults near the leading edge of the Otago reverse fault province

The Titri Fault System is a 5 8 km long, northeast‐striking, southeast‐dipping, reverse fault system situated near the outer (seaward) edge of the Otago reverse fault province, the outboard zone of the Pacific‐Australian convergent plate boundary. Geological mapping and seismic reflection profiles show that the fault system is composed of a master fault and frontal, Quaternary‐active strands. The master fault—the major range‐bounding fault—is the fault on which the majority of both the middle‐Late Cretaceous normal faulting and late Cenozoic reverse faulting took place. The relatively straight map trace, and a fault plane exposure at Snowdrift Quarry of 65°E, indicates a steep fault plane, but is proposed to be listric at depth. Frontal strands, up to 2 km west of the master fault, variably deform alluvial fans, indicating the strands have different Quaternary histories. Map traces of the frontal strands indicate a shallower dip than the master fault and are therefore proposed to be footwall shortcut thrusts. Seismic reflection profiles and drillhole data indicate that a Holocene silt‐sand wedge is not disturbed across the fault system in the southern Taieri Basin area. This is consistent with an absence of deformation of the youngest alluvial fans along the entire fault trace, and collectively indicates that the Titri Fault System has not ruptured in the Holocene. A scarp displacing the second‐youngest alluvial fan set near the southern end of the fault system is the youngest evidence of movement. Correlation of fan formation with major glacial periods indicates this scarp probably dates from the middle of the Last Glacial period. In contrast, the last episode of widespread deformation probably occurred during the Last Interglacial period, or even earlier. Variation in total throw across the fault, the shape of the re‐exposed Late Cretaceous erosion surface on basement of the hanging‐wall block, and variable Quaternary rupture histories for the frontal strands are presented as evidence that the Titri Fault System is segmented. Three segments are proposed, separated by boundaries at the position of the entrances to two antecendent gorges crossing the hanging wall (Taieri and Tokomairiro Rivers). In addition, the parallel, reverse Castle Hill Fault to the south may be acting as a fourth segment.

Ultrashort-laser-pulse measurement using swept beams

We demonstrate a frequency-resolved optical gating (FROG) device that uses a sweepshot geometry that combines the advantages of multishot and single-shot pulse-measurement devices, has only one moving part, a galvanometer, and requires no computer control. Like a multishot device, it focuses the beam to a small spot (rather than a line focus) and has a high intensity in the nonlinear medium. Like single-shot devices, it makes measurements quickly, generating an entire FROG trace on a single camera screen (rather than requiring many camera downloads).

A technique to measure velocities of a ball moving in a tumbling mill and its applications

A technique has been developed to film the entire trace of a ball tumbling in a rotary two-dimensional (2D) mill. With careful calibration, the positions of the ball before and after impact with the mill shell were precisely determined with an image analyzer. Because the image formation process was accurately timed using a digital strobe, the instantaneous speeds of the ball along its trajectory can also be calculated. This makes it possible to (1) investigate the end effect in the experimental two-dimensional mill; (2) evaluate the energy loss during impacts; (3) determine dynamic coefficient of restitution that is an essential parameter in Discrete Element Method (DEM) simulation. Furthermore, this technique permits the charge motion to be analyzed quantitatively in great detail hereby providing precise calibration of the DEM.

Evaluation of a probe for predicting beef tenderness

A series of three experiments were conducted to evaluate the performance of the MIRINZ (Meat Industry Research Institute of New Zealand) tenderness probe. In the first experiment, assessments on raw samples from two different muscles ( longissimus lumborum and semimembranosus) were obtained using the tension head. Results indicated D50 values (torque at 50° of rotation) were the most highly related to both sensory (taste, olfactory, and feeling factors measured by a trained sensory panel) and consumer (hedonic ratings provided by untrained consumers) properties and were the values of choice, since all probe values were essentially measuring the same characteristics. In the second experiment, assessments were made using both the tension and shear heads on raw and cooked striploin ( longissimus lumborum) steaks. Results confirmed probe values were essentially measuring the same characteristics, but indicated raw tension head, area 2 values (area before 50° of rotation) were more highly related to both sensory and consumer properties than were D50 values. However, probe values from raw samples did not account for a sufficient amount of variation in either sensory or consumer properties to be useful predictors of these traits, and stepwise, linear regression did not improve the predictive value of raw probe values, since all probe values were interrelated. Probe values on cooked samples indicated the shear head and area 3 values (area under the entire trace) were the most related to both sensory and consumer properties and were the values of choice. Based upon the amount of variation accounted for in sensory and consumer traits, probe area 3 values using the shear head on cooked samples provided greater predictive value for both sensory and consumer traits than Warner–Bratzler shear values obtained from steaks cooked either fresh or after being frozen and thawed. In experiment 3, correlations with individual, parametric character notes from the texture profiles of two different muscles provided no clear indication as to the textural properties being assessed by the probe. However, the MIRINZ probe appears to be a quick viable alternative to the Warner–Bratzler shear for providing an objective measure of cooked meat tenderness.

The Main Mantle Thrust in Pakistan: its character and extent

Abstract The Main Mantle Thrust (MMT) represents the tectonic boundary between metamorphic shield and platform rock of the Indian plate hinterland, and dominantly mafic and ultramafic rock of the Kohistan-Ladakh arc complex in Pakistan. In some areas, this boundary is a sharp planar fault with development of mylonite; in other areas, it is a brittle-ductile imbricate zone; in still other areas, it contains large, discontinuous, slices of internally sheared and deformed ophiolitic mélange. The character of the MMT along its entire trace is discussed and it is concluded that there is no single continuous fault which marks the contact between the Indian plate and the Kohistan-Ladakh arc. On this basis, we propose a revised definition for the MMT that is consistent with both the original definition and with the usage of the term in literature. We suggest that the MMT fault contact be defined as the series of faults, of different age and tectonic history, that collectively define the northern margin of the Indian plate in Pakistan. On this basis, faults that define the MMT vary in age from Quaternary to possibly as old as Late Cretaceous. Discontinuous lenses of ophiolitic mélange that overlie the MMT fault contact, and which intervene between the Indian plate and the Kohistan-Ladakh arc, are considered to be part of an MMT zone that is equivalent with the Indus Suture Zone.

A simple method for drawing a rational curve as two Bézier segments

In this paper we give a simple method for drawing a closed rational curve specified in terms of control points as two Bézier segments. The main result is the following: For every affine frame (r,s) (where r<s ), for every rational curve F(t) specified over [ r,s ] by some control polygon (β 0 , …, β m ) (where the β zero are weighted control points or control vectors), the control points (θ 0 ,… ,θ m (w.r.t.[ r,s ]) of the rational curve G(t) = F(φ(t)) are given by θ i =(-1) i β i , where φ: RP 1 →RP 1 is the projectivity mapping [ r,s ] onto RP 1 -] r,s ]. Thus, in order to draw the entire trace of the curve F over [-∞,+∞], we simply draw the curve segments F [( r,s ]) and G ([ r,s ]). The correctness of the method is established using a simple geometric argument about ways of partitioning the real projective line into two disjoint segments. Other known methods for drawing rational curves can be justified using similar geometric arguments.

Techniques for performing highly accurate data value prediction

Data dependences (data flow constraints) present a major hurdle to the amount of instruction-level parallelism that can be exploited from a program. Recent work has suggested that the limits imposed by data dependences can be overcome to some extent with the use of data value prediction. That is, when an instruction is fetched, its result can be predicted so that subsequent instructions that depend on the result can use this predicted value. When the correct result becomes available, all instructions that are data dependent on that prediction can be validated. This paper describes a variety of techniques to carry out highly accurate data value predictions. The first technique performs predictions by monitoring the strides by which the results produced, by different instances of an instruction, change. The second technique performs predictions with the use of pattern-based two-level prediction schemes. The third scheme uses a combination of these two predictors to form a hybrid predictor, so as to perform uniformly well across benchmarks. Simulation results of stride based and two-level predictor show improvements over prediction based on the last outcome. In particular, some benchmarks show improvement with the stride-based predictor and others show improvement with the pattern-based predictor. Simulation results of the hybrid predictor show its overall prediction accuracy to be better than that of the component predictors across all benchmarks. Finally, the paper investigates the potential of carrying out data value predictions on an entire trace (of about 15–16 instructions) at a time, so as to reduce the number of access ports required of the predictor. Simulation results show that the accuracy of the predictor does not change markedly when value predictions are carried out at the trace level.

Investigating optimal local memory performance

Recent work has demonstrated that, cache space is often poorly utilized. However, no previous work has yet demonstrated upper bounds on what a cache or local memory could achieve when exploiting both spatial and temporal locality. Belady's MIN algorithm does yield an upper bound, but exploits only temporal locality. In this article, we present an optimal replacement algorithm for local memory that exploits temporal locality and spatial locality simultaneously. This algorithm is an extension of Belady's algorithm. We prove the optimality of this new algorithm with respect to minimizing misses, and we show experimentally that the algorithm produces nearly minimum memory traffic on the SPEC95 benchmarks. Like Belady's algorithm, our algorithm requires the entire program trace. It selects replacement victims and the number of words it fetches at once based on future accesses. Many different spatial locality strategies can be implemented with this algorithm. With an optimal strategy, the algorithm yields an upper bound that enables us to evaluate alternative implementations to today's caches. We further demonstrate the utility of this algorithm as an analysis tool by evaluating several intermediate strategies between cache and optimal to highlight the limitations of the cache line paradigm using the SPEC95 benchmarks.

Investigating optimal local memory performance

Recent work has demonstrated that, cache space is often poorly utilized. However, no previous work has yet demonstrated upper bounds on what a cache or local memory could achieve when exploiting both spatial and temporal locality. Belady's MIN algorithm does yield an upper bound, but exploits only temporal locality. In this article, we present an optimal replacement algorithm for local memory that exploits temporal locality and spatial locality simultaneously. This algorithm is an extension of Belady's algorithm. We prove the optimality of this new algorithm with respect to minimizing misses, and we show experimentally that the algorithm produces nearly minimum memory traffic on the SPEC95 benchmarks. Like Belady's algorithm, our algorithm requires the entire program trace. It selects replacement victims and the number of words it fetches at once based on future accesses. Many different spatial locality strategies can be implemented with this algorithm. With an optimal strategy, the algorithm yields an upper bound that enables us to evaluate alternative implementations to today's caches. We further demonstrate the utility of this algorithm as an analysis tool by evaluating several intermediate strategies between cache and optimal to highlight the limitations of the cache line paradigm using the SPEC95 benchmarks.

Kinetic Study of S. griseus Aminopeptidase by Stopped‐Flow Fluorescence Energy Transfer

AbstractThe stopped‐flow fluorescence traces for the hydrolysis of Leu‐Ala‐DED catalyzed by Streptomyces griseus aminopeptidase isolated from pronase exhibits a two‐phase fluorescence change with comparable rates of formation and breakdown of the ES complex. We have developed a method for the determination of the individual rate constants from the stopped‐flow traces. The kinetic parameters for the enzyme‐catalyzed hydrolysis of Leu‐Ala‐DED at 25 °C and pH 8.0 are: k1 = (1.6±0.1) × 105 M−1s−1, k−1, = 0.089 ± 0.001 s−1, and k2 = 0.58 ± 0.01 s−1. For the observed stopped‐flow traces, the steady state approximation is valid only within a very small region around the maximal ES concentration and a large proportion (> 20%) of the substrate has already been hydrolyzed during the pre‐steady state. For a very fast formation of ES complex, the steady state approximation is valid for almost the entire trace. The activation energies for each individual rate constant were determined to be 10.0 ± 0.7, 35 ± 5, and 21.2 ± 0.8 kcal mol−1 for k1, k−1, and k2, respectively. Binding of E and S to form ES was accompanied by a decrease in Gibbs free energy, whereas a dramatic increase in free energy was observed for the conversion of ES to ES≠. The dissociation of ES to form E and S had a very large activation energy, but it was also accompanied by a large increase in entropy.

Improved powder diffraction patterns for the titanium suboxides TinO2n−1 (4≤n≤9)

Improved powder XRD patterns for the titanium suboxides, TinO2n−1 (4≤n≤9), have been calculated from published single-crystal structures. To provide the best match with experimental data, the entire diffraction traces were simulated, and d-spacings and intensities extracted in the same manner as from experimental traces. The accuracy of the new patterns has been verified by comparison with measured powder patterns, particularly in the case of the n=4 and n=5 compounds where single-phase powders can be prepared relatively easily. Difficulties experienced preparing higher homologues have been related to the thermodynamic properties of this system.

Studies on the metabolism of omeprazole in the rat using liquid chromatography/ionspray mass spectrometry and the isotope cluster technique with [34S]omeprazole.

This paper describes the application of the ionspray (pneumatically-assisted electrospray) interface for liquid chromatography (LC) and atmospheric-pressure ionization mass spectrometry (API MS) to samples obtained in a study on the metabolism of omeprazole. In this study [34S]omeprazole was utilized for the stable isotope cluster technique. Over forty metabolites in a sample of partially purified rat urine were resolved by gradient elution LC with ionspray API MS detection, and each of them produced molecular ion 1:1 clusters (MH+ and [MH + 2]+). The chromatographic fidelity of the total-ion current (TIC) was excellent. The endogenous matrix of the sample was quite low, allowing a background-subtracted averaged mass spectrum of the entire TIC trace to produce a 'metabolite mass profile' depicting all the molecular ion 1:1 clusters in the sample. From this mass profile, it was possible to obtain direct information concerning oxygenation and conjugation reactions of the parent compound.

A portable multi-flash kinetic fluorimeter for measurement of donor and acceptor reactions of Photosystem 2 in leaves of intact plants under field conditions

A newly-developed field-portable multi-flash kinetic fluorimeter for measuring the kinetics of the microsecond to millisecond reactions of the oxidizing and reducing sides of photosystem 2 in leaves of intact plants is described and demonstrated. The instrumental technique is a refinement of that employed in the 'double-flash' kinetic fluorimeter (Joliot 1974 Biochim Biophys Acta 357: 439-448) where a low-intensity short-duration light pulse is used to measure the fluorescence yield changes following saturating single-turnover light pulses. The present instrument uses a rapid series of short-duration (2 μs) pulses to resolve a complete microsecond to millisecond time-scale kinetic trace of fluorescence yield changes after each actinic flash. Differential optics, using a matrix of optical fibers, allow very high sensitivity (noise levels about 0.05% Fmax) thus eliminating the need for signal averaging, and greatly reducing the intensity of light required to make a measurement. Consequently, the measuring pulses have much less actinic effect and an entire multi-point trace (seven points) excites less than 1% of the reaction centers in a leaf. In addition, bu combining the actinic and measuring pulse light in the optical fiber network, the tail of the actinic flash can be compensated for, allowing measurements of events as rapidly as 20 μs after the actinic flash. This resolution makes practical the routine measurement of the microsecond turnover kinetics of the oxygen evolving complex in leaves of intact plants in the field. The instrument is demonstrated by observing flash number dependency and inhibitor sensitivity of the induction and decay kinetics of flash-induced fluorescence transients in leaves of intact plants. From these traces the period-two oscillations associated with the turnover of the two-electron gate and the period-four oscillations associated with the turnover of the oxygen evolving complex can be observed. Applications of the instrument to extending our knowledge of chloroplast function to the whole plant, the effects on plants of environmental stress, herbicides, etc, and possible applications to screening of mutants are discussed.