Miracle-dz/UniFAR-FTUs huggingface dataset:
On the parameterization of equatorial turbulence

Profiles of currents, density, and microstructure were obtained in the Pacific Ocean on and near the equator at 140°W in late 1984 as part of the Tropic Heat program. During a 4½-day time series on the equator, the shear zone above the core of the undercurrent had very low mean Richardson numbers, Ri, between ¼ and ½. Average turbulent dissipation rates, e, were high in this zone, ≈ 10−7 W kg−1, and varied by a factor of 100 between minima in the early afternoon and maxima at night. The signal reached to 90 m, well into the stratified zone. Eddy coefficients, K, were low at high Ri, and gradually increased as Ri decreased, until they rose dramatically near Ri = ½. The observed K(Ri) relations are specific to time, location, and temporal and spatial resolution of the data.
Agile methods and organizational culture: reflections about cultural levels

Agile methods emerge as an alternative to improve quality and performance in software development processes. However, as agile methods are essentially focused on human aspects, their application in companies depends mostly on their adequacy to the current organizational culture. This study explores the view of the organizational culture in three levels as a theoretical framework to allow early detection of problems, which could jeopardize the adoption of agile methods by a company. This article points out that many facilitators or obstacles to the adoption of an agile method can be hidden in the lower levels of the organizational culture. Additionally, the article shows that a superficial analysis of those issues can lead to a miscomprehension about the possibility of applying an agile method in a software company. This article also evidences that the interpretation of the levels of organizational culture improves the understanding of how an agile culture should be established. Copyright © 2009 John Wiley & Sons, Ltd.
Color-Based Object Recognition on a Grid

Multimedia data is rapidly gaining importance along with recent developments such as the increasing deployment of surveillance cameras in public locations, and the need for automatic comparison of forensic video evidence. In a few years time, analyzing the content of multimedia data will be a problem of phenomenal proportions, as digital video may produce data at rates beyond 100 Mb/s, and multimedia archives steadily run into Petabytes of storage space. Consequently, for urgent problems in multimedia content analysis, Grid computing is rapidly becoming indispensable. This paper explores the viability of wide-area Grid systems in adhering to the heavy demands of a real-time task in multimedia content analysis. Specifically, we show the application of a robot dog, capable of recognizing objects from a set of 1,000 learned objects, while connected to a large-scale Grid system comprising of cluster systems in Europe and Australia. Our results indicate that we have reached the moment at which real-time image and video analysis on large-scale Grids is becoming a reality. Moreover, our approach shows the effective integration of stateof-the-art results from two largely distinct research fields: multimedia content analysis and Grid computing.
Effects of age and feeding history on structure-based UV ornaments of a jumping spider (Araneae: Salticidae)

Recent studies have shown for birds that females sometimes choose mates on the basis of condition-dependent variation in ultraviolet (UV, less than 400 nm) ornamentation, but there have been few comparable studies on invertebrates. Yet many invertebrates have UV structural coloration. Here, we investigate Cosmophasis umbratica, a jumping spider (Araneae: Salticidae) that has sexually dimorphic UV-iridescent ornamentation, and we provide evidence that male UV coloration is condition dependent in this species. Spectral-reflection patterns change with male age and prior feeding history. The position of the UV band (i.e. UV hue) of the carapaces of younger (field-collected as subadults and matured as adults in laboratory) males shifted, relative to older (field-collected as adults) males, significantly towards longer wavelengths. Food deprivation significantly decreased the spectral intensity of the abdomen, but not the carapace. Questions concerning the mechanisms by which UV ornaments change are highlighted, as are hypotheses concerning the role of condition-dependent UV variation in male–male competition and as a criterion used by females when making mate-choice decisions.
Chloramphenicol resistance in Pseudomonas cepacia because of decreased permeability

The mechanism of chloramphenicol resistance was examined in a high-level-resistant isolate of Pseudomonas cepacia from a patient with cystic fibrosis. We investigated potential resistance mechanisms, including production of chloramphenicol acetyltransferase, ribosomal resistance, and decreased permeability. This strain (MIC, 200 micrograms/ml) had no detectable chloramphenicol acetyltransferase activity. In in vitro translation experiments in which we compared the resistant isolate with a susceptible strain of P. cepacia, inhibition of amino acid incorporation was equivalent even in organisms that were preincubated with sub-MICs of chloramphenicol. A 21.9-kilobase (kb) fragment of DNA was cloned which coded for chloramphenicol resistance; this fragment was expressed in P. cepacia but not in Escherichia coli. Quantitation of chloramphenicol uptake in the isogenic pair of susceptible and resistant organisms revealed a nearly 10-fold decrease of drug entry into the resistant strain. Comparison of isolated outer membrane proteins and lipopolysaccharide patterns identified no significant differences between the isogenic pair of organisms. We concluded that the mechanism of chloramphenicol resistance in this strain is decreased permeability.
Evaluating GML support for spatial databases

This work presents a study on Geography Markup Language (GML), the issues that arise from using GML for spatial databases and solutions that have been proposed. We concentrate on three aspects of GML, including storage, parsing, and querying. GML is an XML encoding for storing geographic data. It has been developed by the OpenGIS as a medium for uniform geographic data storage and exchange among diverse applications. The underlying concepts of XML therefore can also be applied to GML data. This results in both advantages and disadvantages, which are discussed In the work. GML is a comparatively new language in the field of geographic information systems and still in its developmental stage. Most of the data processing techniques need to be further developed in order for GML to be an efficient medium for geographic data storage and processing.
Turbidity and suspended solids variations downstream of a regulating reservoir

A controlled reservoir release from Llyn Celyn to the Afon Tryweryn, Wales, U.K., has been used to study suspended load and turbidity variations. Turbidity was monitored continuously at two sites and 235 suspended solids samples were obtained at these and three additional sites during the passage of the release wave. The results are compared with data for a natural tributary flood event. The reservoir release data relate to sediment source depletion and reflects changing sources along the channel. Close to the dam, fine organic matter dominates the seston which scanning electron microscopy revealed to be predominantly allochthonous organic matter, with algal fragments and inorganic diatom frustules, derived from the periphyton of the channel bed. Coulter Counter analysis showed the seston to be relatively coarse with a median particle-size of 20 m. Within 3 km of the dam, however, minerogenic particles dominate the sediment load of which more than 90 per cent is finer than 10 m. This represents the flushing of channel-bed accumulations derived from tributary sources. The relationships between suspended sediment concentration and turbidity during the release are characterized by a marked, anticlockwise hysteresis. This contrasts with the clockwise hysteresis for the tributary flood event, but the different relationships cannot be explained by particle-size variations alone; seston composition also appears to be an important control.
Protein-phospholipid-cholesterol interaction in the photolysis of invertebrate rhodopsin.

Three aspects of protein-phospholipid-cholesterol interaction in microvillar membranes of octopus photoreceptor cells were studied: (1) the effect of hydrophobic environment on the kinetics of thermal transformation in the photolysis of rhodopsin; (2) effects of cholesterol in microvillar membranes on protein-lipid interaction; (3) the effect of membrane pro- teins on the dynamic properties of lipids in membranes. Dynamic properties of hydrophobic environments were ob- served with electron spin resonance spectroscopy with various lipid spin-labels. The kinetics of thermal transformation of mesorhodopsin to metarhodopsin was followed by flash pho- tolysis experiments. The thermal stability of mesorhodopsin was followed by low-temperature spectrophotometry. The rate of transformation is influenced by the properties of both hy- drophobic environments and temperature. The effect of the former is prominent at physiological temperatures, while the A number of functions of proteins are greatly facilitated by the internal fluctuation of protein conformation (for a recent review, see Careri et al. (1979) and Karplus & McCammon (1981)l. Oosawa (1973, 1975) emphasized the importance of the environmental fluctuation of electric potential around proteins with long correlation times and long correlation lengths' in determining the reaction rate of enzymes. This type of spontaneous environmental fluctuation occurs relatively rarely but supplies sufficient free energy, coupled with internal protein fluctuation, to enhance enzymatic activity. The hy- drophobic portion of biological membranes is of particular interest in this respect because the spectrum of spontaneous fluctuations is expected to shift to longer correlation times and lengths due to the higher viscosity and ordered structure of hydrophobic loci in membranes. One of the aims of this work is to study the influence of the environment on the function of the protein. The thermal conversion of the photochemical intermediates of rhodopsin (a membrane protein) after pho- tolysis gives an ideal model for the study of the relationship between the function of the protein and the environment, since the transformation of the intermediates (hypso-batho-lumi- meso-meta) is strictly thermally driven and the photochemical process is well established (Yoshizawa, 1972; Tsuda et al., 1980; Tsuda, 1982a).
The inverse problem of the shear modulus and density profiles of a layered Earth

It is shown that the shear modulus and density profiles of a layered, isotropic elastic earth can be uniquely inferred from the displacement of the surface due to an impulsive SH line source. An inversion algorithm is presented which constructs these profiles from the surface data. Two illustrative examples are given in which the shear modulus and density profiles are reconstructed analytically from an analytic surface data.
The timing of major climate terminations

A simple, untuned “constant sedimentation rate” timescale developed using three radiometric age constraints and eleven δ18O records longer than 0.8 Myr provides strong support for the validity of the SPECMAP timescale of the late Quaternary [Imbrie et al., 1984]. In particular, the present study independently confirms the link between major deglaciations (terminations) and increases in northern hemisphere summer radiation at high latitudes and shows that this correlation is not an artifact of orbital tuning. In addition, the excess ice characteristic of late Quaternary “100-kyr” climate cycles typically accumulates when July insolation at 65°N has been unusually low for more than a full precessional cycle, or >21 kyr, and once established does not last beyond the next increase in summer insolation. Thus, the timing of the growth and decay of large 100-kyr ice sheets, as depicted in the deep sea δ18O record, is strongly (and semipredictably) influenced by eccentricity through its modulation of the orbital precession component of northern hemisphere summer insolation.
An Efficient Process Live Migration Mechanism for Load Balanced Distributed Virtual Environments

Distributed virtual environments (DVE), such as multi-player online games and distributed simulations may involve a massive amount of concurrent clients. Deploying distributed server architectures is currently the most prevalent way of providing such large-scale services, where typically the virtual space is divided into several distinct regions requiring each server to handle only part of the virtual world. Inequalities in client distribution may, however, cause certain servers to become overloaded, which potentially degrades the interactivity of the environment and thus renders the load balancing problem a crucial issue. Prior research has shown several approaches for avoiding uneven workload, nevertheless, addressing the problem mainly at the application layer. In this paper we focus on solving the DVE load balancing problem at the operating system level. We propose an efficient process live migration mechanism, which is optimized for processes maintaining a massive amount of network connections. Building on top of it, we have implemented a decentralized middleware that instruments process migration among the cluster nodes, attempting to equalize loads on all machines. We demonstrate the performance of the live migration mechanism on a real-world multiplayer game server and show the behavior of the load balancing engine through a realistic DVE simulation.
Long‐term oscillations of the wind field in the tropical mesosphere and lower thermosphere from Hawaii MF radar measurements

[1] Wind measurements in the mesosphere and lower thermosphere obtained with a medium frequency (MF) radar in Hawaii (22°N, 160°W) spanning ∼16 years are employed to examine the intra-annual and interannual variability of the mean and tidal motions at altitudes between 84 and 94 km. Intra-annual periodicities range from ∼3 to 12 months, with significant coherence in altitude and between the zonal and meridional components of each motion field. Interannual variations confirm the dominant periodicities identified previously at this site and elsewhere, in particular, the significant diurnal, and less significant semidiurnal, tidal responses at periods of ∼28 and ∼48 months. Amplitudes of these long-period oscillations of the diurnal tide increase with altitude below 92 km and are larger than the amplitudes of the 12 month oscillations above ∼90 km. Phases of the ∼28 and ∼48 month oscillations show a downward progression with a slightly larger altitude variation in the meridional diurnal tide for the ∼28 month oscillation and a significantly larger altitude variation in the zonal diurnal tide for the ∼48 month oscillation. The long and nearly continuous Hawaii data set also enables characterization of the responses of the wind fields to the 11 year solar cycle. Both wind and tidal fields exhibit this periodicity, but these responses display interesting and different relations to the phase of the solar cycle. The 11 year oscillation of the meridional wind is nearly in phase with the solar cycle, while the 11 year oscillation of the zonal wind is in approximate quadrature with the solar cycle. The 11 year oscillations of the semidiurnal tidal amplitudes and the meridional diurnal amplitude are all in approximate quadrature with the solar cycle (with the tidal amplitudes leading by ∼29 to 37 months), while the 11 year oscillation of the zonal diurnal amplitude is somewhat nearer an antiphase than a quadrature relation to the solar cycle (leading by ∼54 months).
High‐pressure elasticity of serpentine and seismic properties of the hydrated mantle wedge

A subset of the single‐crystal elastic moduli of natural antigorite has been measured using Brillouin scattering at high‐pressure up to 9 GPa. Aggregate properties and axial compressibilities are in good agreement with equation‐of‐state results from X‐ray diffraction. Stiffness along the c‐axis increases, becoming close to those within the silicate layer near 7 GPa. A slight discontinuity in the evolution of the elastic moduli near 7 GPa is associated with a phase transition. Raman spectroscopy shows that the transition does not occur in subducting slabs, except in the core of the coldest slabs where serpentine may be subducted to depths of about 200 km. Varying temperature and pressure has limited effects on the interpretation of seismic velocities, principally because of the limited depth range of serpentine stability (mostly above 100 km depth), and also due to the compensating effects of pressure and temperature that maintain velocity variations well within the uncertainties and statistical variability of seismological studies. Serpentinites are excellent candidates for explaining low velocities in the hydrated mantle wedge, inversion of the Moho, and thin anisotropic low‐velocity layers at the plate interface. Serpentinite layers provide an alternative explanation to fluid‐saturated oceanic crust for explaining these phenomena, and account for a transition to an aseismic, decoupled plate interface.
Linking migration, mobility and HIV

Population mobility is commonly identified as a key driver of the HIV epidemic, both linking geographically separate epidemics and intensifying transmission through inducing riskier sexual behaviours. However, beyond the well‐known case studies of South African miners and East African truck drivers, the evidence on the links between HIV and mobility is nuanced, contradictory and inconclusive and is in part attributed to the abstract definitions of mobility used in different studies. This problematic conception of mobility, with no reference to who moves, their motivations for moving, or the characteristics of sending and receiving areas, can have a dramatic impact on how one understands the influence which this structural factor has on HIV risk in different settings. Future research on mobility and HIV transmission must incorporate an understanding of migration and mobility as dynamic processes and link different patterns and forms of mobility with location‐specific sexual networks and HIV epidemiology.
Ventilation of Red Sea Water with respect to chlorofluorocarbons

Chlorofluorocarbon (CFC) measurements were made in the northwestern Indian Ocean in August-September 1995 as part of the World Ocean Circulation Experiment Hydrographic Program Section I1. The data in the Gulf of Aden section from this expedition provide information on the mixing processes that affect Red Sea Water (RSW) as it flows from its source into the open northwestern Indian Ocean. Combining measurements by Rhein et al. [1997] with the outcome from a two-end-member mixing model results in an estimate of 65–70% saturation for the CFCs in the RSW end-member at Bab el Mandeb. A boundary condition that may be more applicable to ocean models is given by the CFC content of RSW after its initial diapycnal descent along the continental slope in the western Gulf of Aden. Entrainment of water containing lower amounts of CFCs produces RSW that has CFC saturations of 20–50% once RSW has settled at its depth of neutral buoyancy. Apparent pCFC ages at Bab el Mandeb and after the separation of RSW from the bottom are 12–13 and 18–27 years, respectively. As RSW continues eastward through the Gulf of Aden as an isopycnal flow, horizontal eddy diffusion plays an important role in further diluting RSW, which is characterized by a maximum in salinity and a positive anomaly in CFC concentrations. Horizontal eddy diffusion parameters estimated from tracer conservation in a box model of the central and eastern Gulf of Aden range from 0.2 × 104 to 2.0 × 104 m2 s−1. As other observations show, eddy diffusion is presumably enhanced in this part of the ocean.
Hot spot activity and tectonic settings near Amsterdam–St. Paul plateau (Indian Ocean)

[1] The Amsterdam–St. Paul (ASP) plateau is located in the central part of the Indian Ocean and results from the interaction between the ASP hot spot and the Southeast Indian Ridge (SEIR). It is located near the diffuse boundary between the Capricorn and Australian plates. The seamount chain of the Dead Poets (CDP) is northeast of the ASP plateau and may represent older volcanism related to the ASP hot spot; this chain consists of two groups of seamounts: (1) large flat-topped seamounts formed 8–10 Ma and (2) smaller conical seamounts formed during the last 2 Myr. The ASP hot spot has produced two pulses of magmatism that have been ponded under the ASP plateau and erupted along the divergent boundary between the Capricorn and Australian plates. The N65° orientation of the CDP as well as the seamount's elongated shapes support an opening motion between the Capricorn and Australian plates along a suture oriented in the N155° direction. This motion compared to the Antarctic plate amounts to an apparent velocity of 7.7 cm/yr northeastward for the Capricorn-Australian block. This motion does not fit with a fixed plume model. We suggest, therefore, that the ASP plume experienced a motion of about 1–2 cm/yr to the SW, which is opposite to the asthenospheric flow in this region and suggests a deep-seated plume.
Mechanism of Electromechanical Coupling in Voltage-Gated Potassium Channels

Voltage-gated ion channels play a central role in the generation of action potentials in the nervous system. They are selective for one type of ion – sodium, calcium, or potassium. Voltage-gated ion channels are composed of a central pore that allows ions to pass through the membrane and four peripheral voltage sensing domains that respond to changes in the membrane potential. Upon depolarization, voltage sensors in voltage-gated potassium channels (Kv) undergo conformational changes driven by positive charges in the S4 segment and aided by pairwise electrostatic interactions with the surrounding voltage sensor. Structure-function relations of Kv channels have been investigated in detail, and the resulting models on the movement of the voltage sensors now converge to a consensus; the S4 segment undergoes a combined movement of rotation, tilt, and vertical displacement in order to bring 3–4e+ each through the electric field focused in this region. Nevertheless, the mechanism by which the voltage sensor movement leads to pore opening, the electromechanical coupling, is still not fully understood. Thus, recently, electromechanical coupling in different Kv channels has been investigated with a multitude of techniques including electrophysiology, 3D crystal structures, fluorescence spectroscopy, and molecular dynamics simulations. Evidently, the S4–S5 linker, the covalent link between the voltage sensor and pore, plays a crucial role. The linker transfers the energy from the voltage sensor movement to the pore domain via an interaction with the S6 C-termini, which are pulled open during gating. In addition, other contact regions have been proposed. This review aims to provide (i) an in-depth comparison of the molecular mechanisms of electromechanical coupling in different Kv channels; (ii) insight as to how the voltage sensor and pore domain influence one another; and (iii) theoretical predictions on the movement of the cytosolic face of the Kv channels during gating.
High antibody level: an accurate serologic marker of viremia in asymptomatic people with hepatitis C infection

BACKGROUND: The screening and diagnosis of hepatitis C virus (HCV) infection is initiated by testing for antibody to HCV (anti‐HCV). A positive anti‐HCV test in blood donors represents ongoing infection in only a variable proportion of individuals. Because a high anti‐HCV level has been associated with viremia, a study was conducted to determine whether a high antibody level is an accurate serologic marker for viremia in asymptomatic anti‐HCV–positive persons.