Tracing energy inputs into the seafloor using carbonate sediments.

Carbonate rocks provide unique and valuable sedimentary archives for secular changes in Earth's physical, chemical, and biological processes. However, reading the stratigraphic record produces overlapping, nonunique interpretations that stem from the difficulty in directly comparing competing biological, physical, or chemical mechanisms within a common quantitative framework. We built a mathematical model that decomposes these processes and casts the marine carbonate record in terms of energy fluxes across the sediment-water interface. Results showed that physical, chemical, and biological energy terms across the seafloor are subequal and that the energetic dominance of different processes varies both as a function of environment (e.g., onshore vs. offshore) as well as with time-varying changes in seawater chemistry and with evolutionary changes in animal abundance and behavior. We applied our model to observations from the end-Permian mass extinction-a massive upheaval in ocean chemistry and biology-revealing an energetic equivalence between two hypothesized drivers of changing carbonate environments: a reduction in physical bioturbation increased carbonate saturation states in the oceans. Early Triassic occurrences of 'anachronistic' carbonates-facies largely absent from marine environments after the Early Paleozoic-were likely driven more by reduction in animal biomass than by repeated perturbations to seawater chemistry. This analysis highlighted the importance of animals and their evolutionary history in physically shaping patterns in the sedimentary record via their impact on the energetics of marine environments.

Experimental Demonstration of Hadron Beam Cooling Using Radio-Frequency Accelerated Electron Bunches.

Cooling of beams of gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens the possibility of using this technique at higher energies than possible with electrostatic acceleration of electron beams. The challenges of this approach include generation of electron beams suitable for cooling, delivery of electron bunches of the required quality to the cooling sections without degradation of beam angular divergence and energy spread, achieving the required small angles between electron and ion trajectories in the cooling sections, precise velocity matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched-beam cooling. Here we report on the first demonstration of cooling hadron beams using this new approach.

[Injuries of the medial collateral ligament and spring ligament complexes]. / Verletzungen des medialen Kollateralband- und "Spring-ligament"-Komplexes.

The medial collateral ligament (MCL) complex is characterized by a complex anatomical arrangement of the individual ligamentous structures including three joints and the spring ligament complex. Biomechanically it serves as the main stabilizing structure in the ankle region against rotational and pronating forces. Lesions in the region of the MCL complex are more frequent than previously thought and like lesions of the spring ligament complex can lead to pain and instability. A thorough examination including the patient history with possible injury mechanisms often yields valuable information on the diagnosis of injuries to the MCL or spring ligament complex. In many cases these are primarily overlooked and concomitant lesions, such as fractures, syndesmotic and lateral ligament lesions frequently occur; however, the clinical assessment of stability is often primarily impossible in an acute setting. High-resolution magnetic resonance imaging (MRI) plays a key role in identifying the ligamentous components. In addition, MRI plays a supportive role in the preoperative planning before reconstruction of acute and especially chronic lesions. In most cases the surgical treatment of acute ruptures of the MCL is not indicated. Various options for treatment of acute and chronic lesions of the MCL and spring ligament complex are available including the use of free tendon grafts. Controversy exists regarding the operative treatment of MCL lesions in the case of ankle fractures. It is recommended for cases with impinging tissue in the medial gutter serving as a barrier to adequate reduction of the joint and in cases of unstable fractures after reduction.

Mechanical Circulatory Support in the Treatment of Advanced Heart Failure.

According to the Centers for Disease Control, heart failure (HF) remains a pervasive condition with high morbidity and mortality, affecting 5.8 million people in the United States and 23 million worldwide. For patients with refractory end-stage HF, heart transplantation is the "gold standard" for definitive treatment. However, the demand for heart transplantation has consistently exceeded the availability of donor hearts, with approximately 2331 orthotopic heart transplantations performed in the United States in 2015 despite an estimated 100 000 to 250 000 patients with New York Heart Association class IIIB or IV symptoms that are refractory to medical treatment, making such patients potential transplant candidates. As such, the need for mechanical circulatory support (MCS) to treat patients with end-stage HF has become paramount. In this review, we focus on the history, advancements, and current use of durable MCS device therapy in the treatment of advanced heart failure.

Bilateral chorioretinopathy in child-onset systemic lupus erythematosus.

Any of the various layers of the eye may suffer injury in systemic lupus erythematosus, ranging from keratoconjunctivitis sicca to retinopathy and optic neuritis. Rheumatologists must always be aware of ocular involvement in those patients since rapid diagnosis and a prompt intervention in those severe cases can prevent visual loss or even irreversible blindness. We present here the case of a 14-year-old girl who, despite a short period of disease, developed chorioretinopathy with transitory visual impairment with a good treatment response.

Operational Head-on Beam-Beam Compensation with Electron Lenses in the Relativistic Heavy Ion Collider.

Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider in order to increase the luminosity delivered to the experiments. We discuss the principle of combining a lattice for resonance driving term compensation and an electron lens for tune spread compensation. We describe the electron lens technology and its operational use. To date, the implemented compensation scheme approximately doubled the peak and average luminosities.

No evidence for development of tolerance after repeated use of propofol for electroconvulsive therapy.

INTRODUCTION: The short-acting narcotic propofol is used for sedation during electroconvulsive therapy (ECT). It remains unclear whether patients develop tolerance to propofol after repeated administration. Therefore, we studied whether propofol dosage had to be increased during a course of ECT. METHODS: This retrospective study evaluated records of 39 in- and outpatients at a Swiss psychiatric hospital who underwent 10-21 ECT sessions for affective disorder over 4-28 weeks in 2011-2013. We examined the dose of propofol required to achieve deep sedation at the first and last ECT sessions. RESULTS: 13/39 patients (33.3%) needed a slightly higher propofol dose at the last ECT session than at the first (Group 1), 12 patients (30.8%) needed the same dose at the first and last sessions (Group 2) and 14 patients (35.9%) needed a lower final dose (Group 3). CONCLUSIONS: In our study patients did not appear to develop tolerance to propofol after repeated administration. Although the lack of a systematic dosing scheme in our study limits the conclusions that can be drawn, recent studies in animal models indicate that tolerance development is rather unlikely with propofol. Further studies are required to clarify the question of whether repeated use of propofol leads to tolerance.

Tanshinone II A sulfonate, but not tanshinone II A, acts as potent negative allosteric modulator of the human purinergic receptor P2X7.

Tanshinone II A sulfonate (TIIAS) was identified as a potent, selective blocker of purinergic receptor P2X7 in a compound library screen. In this study, a detailed characterization of the pharmacologic effects of TIIAS on P2X7 is provided. Because TIIAS is a derivative of tanshinone II A (TIIA) and both compounds have been used interchangeably, TIIA was included in some assays. Fluorometric and electrophysiologic assays were used to characterize effects of TIIAS and TIIA on recombinantly expressed human, rat, and mouse P2X7. Results were confirmed in human monocyte-derived macrophages expressing native P2X7. In all experiments, involvement of P2X7 was verified using established P2X7 antagonists. TIIAS, but not TIIA, reduces Ca(2+) influx via human P2X7 (hP2X7) with an IC50 of 4.3 µM. TIIAS was less potent at mouse P2X7 and poorly inhibited rat P2X7. Monitoring of YO-PRO-1 uptake confirmed these findings, indicating that formation of the hP2X7 pore is also suppressed by TIIAS. Electrophysiologic experiments revealed a noncompetitive mode of action. TIIAS time-dependently inhibits hP2X7 gating, possibly by binding to the intracellular domain of the receptor. Inhibition of native P2X7 in macrophages by TIIAS was confirmed by monitoring Ca(2+) influx, YO-PRO-1 uptake, and release of the proinflammatory cytokine interleukin-1ß. Fluorometric experiments involving recombinantly expressed rat P2X2 and human P2X4 were conducted and verified the compound's selectivity. Our data suggest that hP2X7 is a molecular target of TIIAS, but not of TIIA, a compound with different pharmacologic properties.

MRI identification of pseudolesions in the distal tibia articular surface: Frequency and diagnostic criteria.

OBJECTIVE: Pseudolesions of joints are known as focal irregularities of chondral or subchondral bone in typical joint areas and occur frequent but without clinical relevance. This study aims to report the prevalence and describe MRI findings of a previously unreported chondral, mostly posterior located pseudolesion of the distal tibia, and to define criteria to distinguish it from pathologic osteochondral lesions, as well as from another known pseudolesion of this area - the so called "Notch of Harty". MATERIAL AND METHODS: A tri-centric retrospective case-control study included a total of 2,428 patients with ankle MRI examinations performed over a period of 6 years. MRI scans were evaluated by three radiologists in consensus for any cartilage irregularity of the distal tibial articular surface. For this purpose, the tibial articular surface was divided into 9 topographic regions. Proton-density weighted, fat-suppressed sequences in sagittal and coronal acquisition were used to assess the postero-medial articular surface of the tibia. Imaging features such as size and localization of cartilage irregularity and/or a cortical mould as well as presence of associated edema and/or subchondral cysts were reported. Demographic data (sex, age, and weight) was also recorded. Clinical data comprised presence of pain, movement impairment, and concomitant pathologies. RESULTS: A total of 68 patients (34 male, 34 female) with a lesion of the distal tibia were identified that had a new pseudolesion (prevalence of 3%). These lesions occurred most frequently (50 out of 68, 74%) in the postero-medial distal tibia plafond and were more commonly detected in the age group of 9-30 years (47%). In 13 of these 68 cases, the cartilage irregularity was the sole lesion without subchondral abnormalities. By defining these cases as definite pseudolesions, the prevalence was 1% and their age distribution was similar to that of the 55 other lesions with subchondral changes. Here with 11 of the 13 cases the majority (85%) were seen in the posterior part, especially in the postero-medial part (55%) of the distal tibia. The size of the cartilage defect ranged from 1 to 7 mm, and the majority (69%) sized from 2 to 3 mm. In 36 of 68 patients, we have seen subchondral alterations such as edema and/or cysts in addition to cartilage irregularity. 66% (n = 45) of these changes were edema and 37% (n = 25) were cysts. None of these 68 new pseudolesions with or without subchondral changes needed surgical or arthroscopic intervention. In the radiological and orthopaedic reports, clinical symptoms such as pain or instability were never associated with our observed lesions and there was no significant correlation between the presence of motion-related pain and imaging findings of cartilage irregularity, subchondral edema, and subchondral cysts. Thirteen patients had MRI follow-up examinations. Here the lesions did not show any MR morphological changes or clinical deterioration. Besides the new pseudolesion, which occured mainly in the posterior part of the tibia surface, we observed the "Notch of Harty" with a higher prevalence (25%) in our patient cohort. The typical localization was in the antero-medial tibial articular surface, without any edema or cysts. There were no coincidences of patients with both a new pseudolesion and the "Notch of Harty" CONCLUSION: A new pseudolesion is typically seen in the postero-central and postero-medial tibial articular surface with a prevalence of 3% and may be associated with only a small cartilage irregularity. In many cases, however, additional findings such as bone edema and/or an adjacent bone cysts were found, which impairs differentiation of these lesions from pathologic osteochondral lesions. The latter are obviously often associated with a larger cartilage defect and clinical symptoms. Due to the balanced age distribution between those pseudolesions with and without subchondral changes and the lack of clinical symptoms, we conclude that the here reported pseudolesions are not a predilection for a clinically manifest osteochondral lesion (OCL). At the very least, the apparent lack of clinical relevance increases the likelihood that we are dealing with a new true pseudolesion.

Five novel locations of Neocentromeres in human: 18q22.1, Xq27.1∼27.2, Acro p13, Acro p12, and heterochromatin of unknown origin.

Since the first report in 1993, an ectopic centromere, i.e. neocentromere formation, has been reported in more than 100 small supernumerary marker chromosomes (sSMC), in 7 instances of centromere repositioning, and in about a dozen cases with more complex chromosomal rearrangements. Here we report 2 new cases with centromere repositioning and 3 neocentric sSMC consisting exclusively of heterochromatic material. Yet, no centromere formation was reported for the regions 18q22.1 and Xq27.1∼27.2 as it was observed in the 2 cases with centromere repositioning here; in both cases, cytogenetically an inversion was suggested. Two of the 3 neocentric sSMC were derived from a short arm of an acrocentric chromosome. The remainder neocentric sSMC case was previously reported and was stainable only by material derived from itself.

In situ fabrication of ultrathin porous alumina and its application for nanopatterning Au nanocrystals on the surface of ion-sensitive field-effect transistors.

In situ fabrication in a single step of thin films of alumina exhibiting a thickness of less than 100 nm and nanopores with a highly regular diameter distribution in order to pattern nanostructures over field-effect devices is a critical issue and has not previously been demonstrated. Here we report the fabrication in situ of 50 nm thick ultrathin nanoporous alumina membranes with a regular pore size directly over metal-free gate ion-sensitive field-effect transistors. Depositing thin films of aluminum by an electron beam at a relatively low rate of deposition on top of chips containing the transistors and using a conventional single-step anodization process permits the production of a well-adhering nanoporous ultrathin layer of alumina on the surface of the devices. The anodization process does not substantially affect the electrical properties of the transistors. The small thickness and pore size of ultrathin alumina membranes allow them to be sequentially employed as masks for patterning Au nanocrystals grown by an electroless approach directly on the top of the transistors. The patterning process using a wet chemical approach enables the size of the patterned crystals to be controlled not only by the dimensions of the pores of alumina, but also by the concentration of the reactants employed. Surface modification of these nanocrystals with alkanethiol molecules demonstrates that the electrostatic charge of the functional groups of the molecules can modulate the electrical characteristics of the transistors. These results represent substantial progress towards the development of novel nanostructured arrays on top of field-effect devices that can be applied for chemical sensing or non-volatile memories.

[Seroprevalence of Toxoplasma gondii in students with occupational risk]. / Seroprevalencia de Toxoplasma gondii en estudiantes con riesgo ocupacional.

BACKGROUND: Toxoplasmosis is a disease that results from infection with the Toxoplasma gondii parasite, one of the world's most common parasites. The zoonotic infection usually occurs by eating undercooked contaminated meat or by contact with contaminated cat feces. A few studies of toxoplasmosis in healthy and immuno-compromised persons were done in Chile, but investigations related to occupational risk groups, such as Veterinary Medicine students were not studied. AIM: Determine the seroprevalence for T. gondii in Veterinary Medicine students at a university located in the center-south of the country, and evaluated to association with intrinsic variables. METHODS: Peripheral blood samples were taken from 74 veterinary students from a university in south-central Chile. Immunoassay with sequential chemiluminescent was used as diagnostic technique. RESULTS: Of the total number of students, 16 were seropositive, which is equivalent to 21.6%, the largest number of seropositive students was female (75%), they were in the age range between 24 and 26 years of age (43.7%), all consumed meat and vegetables (100%) and collected pet cat feces without protection 50 (68,7%). CONCLUSIONS: The results obtained show the presence of antibodies against T. gondii in Veterinary Medicine students. To the authors' knowledge, it is the first serological study for toxoplasmosis performed in university students of Veterinary Medicine in Chile.

Alteplase (rtPA) treatment of intraventricular hematoma (IVH): safety of an efficient methodological approach for rapid clot removal.

Intraventricular hemorrhage (IVH) subsequent to intracerebral hemorrhage (ICH) or subarachnoid hemorrhage (SAH) is associated with high mortality and morbidity. The use of fibrinolytic agents to treat this condition has previously been reported in small clinical trials with limited numbers of patients. Variability regarding inclusion criteria, method of administration and outcome have made it difficult to draw firm conclusions regarding the efficacy of antifibrinolytic therapy. Nine patients with CT-diagnosed IVH were treated with Alteplase intrathecally for 3 to 5 days according to the CT-verified clearance of IVH. After the treatment period, a repeat CT scan was performed to evaluate treatment effect.In this safety study, we achieved rapid removal of IVH compared to retrospective controls, without incidents of re-bleeding, with only 33% permanent shunt placements and a neurological outcome of GOS of 4-5 in 44% of the patients. Based on the above results, the treatment protocol was considered safe and highly effective. A prospective randomized national multicenter trial has been initiated in order to evaluate the efficacy of this novel method also in terms of outcome and shunt dependency.

Ancient Oil as a Source of Carbonaceous Matter in 1.88-Billion-Year-Old Gunflint Stromatolites and Microfossils.

The 1.88-billion-year-old Gunflint carbonaceous microfossils are renowned for their exceptional morphological and chemical preservation, attributed to early and rapid entombment in amorphous silica. The carbonaceous matter lining and partly filling filamentous and spherical structures is interpreted to be indigenous, representing thermally altered relicts of cellular material (i.e., kerogen). Here we show that stromatolitic black cherts from the Gunflint Formation, Schreiber Beach, Ontario, Canada, were saturated in syn-sedimentary oil. The thermally altered oil (pyrobitumen), which occurs in the stromatolites and intercolumn sediments, fills pores and fractures, and coats detrital and diagenetic grain surfaces. The occurrence of detrital bitumen grains in the stromatolites points to the proximity of shallow seafloor oil seeps and hence the possible existence of chemosynthetic microbes degrading hydrocarbons. We suggest that hydrocarbons that migrated through the silicifying stromatolites infiltrated semi-hollow microbial molds that formed following silica nucleation on the walls or sheaths of decayed cells. Upon heating, the hydrocarbons were transformed to nanoporous pyrobitumen, retarding silica recrystallization and enhancing detailed preservation of the carbon-rich microfossils. Hydrocarbon infiltration of silicified microbes offers a new explanation for the preservation of the Gunflint microfossils and may have played a role in the formation of some of Earth's oldest microfossils.

Greenalite Nanoparticles in Alkaline Vent Plumes as Templates for the Origin of Life.

Mineral templates are thought to have played keys roles in the emergence of life. Drawing on recent findings from 3.45-2.45 billion-year-old iron-rich hydrothermal sedimentary rocks, we hypothesize that greenalite (Fe3Si2O5(OH)4) was a readily available mineral in hydrothermal environments, where it may have acted as a template and catalyst in polymerization, vesicle formation and encapsulation, and protocell replication. We argue that venting of dissolved Fe2+ and SiO2(aq) into the anoxic Hadean ocean favored the precipitation of nanometer-sized particles of greenalite in hydrothermal plumes, producing a continuous flow of free-floating clay templates that traversed the ocean. The mixing of acidic, metal-bearing hydrothermal plumes from volcanic ridge systems with more alkaline, organic-bearing plumes generated by serpentinization of ultramafic rocks brought together essential building blocks for life in solutions conducive to greenalite precipitation. We suggest that the extreme disorder in the greenalite crystal lattice, producing structural modulations resembling parallel corrugations (∼22 Šwide) on particle edges, promoted the assembly and alignment of linear RNA-type molecules (∼20 Šdiameter). In alkaline solutions, greenalite nanoparticles could have accelerated the growth of membrane vesicles, while their encapsulation allowed RNA-type molecules to continue to form on the mineral templates, potentially enhancing the growth and division of primitive cell membranes. Once self-replicating RNA evolved, the mineral template became redundant, and protocells were free to replicate and roam the ocean realm.

Evidence for a Diagenetic Origin of Vera Rubin Ridge, Gale Crater, Mars: Summary and Synthesis of Curiosity's Exploration Campaign.

This paper provides an overview of the Curiosity rover's exploration at Vera Rubin ridge (VRR) and summarizes the science results. VRR is a distinct geomorphic feature on lower Aeolis Mons (informally known as Mount Sharp) that was identified in orbital data based on its distinct texture, topographic expression, and association with a hematite spectral signature. Curiosity conducted extensive remote sensing observations, acquired data on dozens of contact science targets, and drilled three outcrop samples from the ridge, as well as one outcrop sample immediately below the ridge. Our observations indicate that strata composing VRR were deposited in a predominantly lacustrine setting and are part of the Murray formation. The rocks within the ridge are chemically in family with underlying Murray formation strata. Red hematite is dispersed throughout much of the VRR bedrock, and this is the source of the orbital spectral detection. Gray hematite is also present in isolated, gray-colored patches concentrated toward the upper elevations of VRR, and these gray patches also contain small, dark Fe-rich nodules. We propose that VRR formed when diagenetic event(s) preferentially hardened rocks, which were subsequently eroded into a ridge by wind. Diagenesis also led to enhanced crystallization and/or cementation that deepened the ferric-related spectral absorptions on the ridge, which helped make them readily distinguishable from orbit. Results add to existing evidence of protracted aqueous environments at Gale crater and give new insight into how diagenesis shaped Mars' rock record.

MRI-detected subchondral bone marrow signal alterations of the knee joint: terminology, imaging appearance, relevance and radiological differential diagnosis.

OBJECTIVE: To discuss terminology, radiological differential diagnoses and significance of magnetic resonance imaging (MRI)-detected subchondral bone marrow lesions (BMLs) of the knee joint. METHODS: An overview of the published literature is presented. In addition, the radiological appearance and differential diagnosis of subchondral signal alterations of the knee joint are discussed based on expert consensus. A recommendation for terminology is provided and the relevance of these imaging findings for osteoarthritis (OA) research is emphasized. RESULTS: A multitude of differential diagnoses of subchondral BMLs may present with a similar aspect and signal characteristics. For this reason it is crucial to clearly and specifically define the type of BML that is being assessed and to use terminology that is appropriate to the condition and the pathology. In light of the currently used terminology, supported by histology, it seems appropriate to apply the widely used term "bone marrow lesion" to the different entities of subchondral signal alterations and in addition to specifically and precisely define the analyzed type of BML. Water sensitive sequences such as fat suppressed T2-weighted, proton density-weighted, intermediate-weighted fast spin echo or short tau inversion recovery (STIR) sequences should be applied to assess non-cystic BMLs as only these sequences depict the lesions to their maximum extent. Assessment of subchondral non-cystic ill-defined BMLs on gradient echo-type sequences should be avoided as they will underestimate the size of the lesion. Differential diagnoses of OA related BMLs include traumatic bone contusions and fractures with or without disruption of the articular surface. Osteonecrosis and bone infarcts, inflammation, tumor, transient idiopathic bone marrow edema, red marrow and post-surgical alterations should also be considered. CONCLUSION: Different entities of subchondral BMLs that are of relevance in the context of OA research may be distinguished by specific imaging findings, patient characteristics, symptoms, and history and are discussed in this review.

Freeze etching of cells without cryoprotectants.

The technique of spray-freeze etching was applied to unicellular organisms. The superior freezing rates obtainable with this method gave excellent cryofixation on Chlorella, Euglena, and spermatozoa without the use of antifreeze agents, and cell damage due to ice crystal formation was never observed. In many instances the resultant morphology differed significantly from that obtained from glycerol-treated, freeze-etched cells. Furthermore, viability studies of spray-frozen Chlorella compared favorably with cells frozen by other methods.

Novel vertebrate nucleoporins Nup133 and Nup160 play a role in mRNA export.

RNA undergoing nuclear export first encounters the basket of the nuclear pore. Two basket proteins, Nup98 and Nup153, are essential for mRNA export, but their molecular partners within the pore are largely unknown. Because the mechanism of RNA export will be in question as long as significant vertebrate pore proteins remain undiscovered, we set out to find their partners. Fragments of Nup98 and Nup153 were used for pulldown experiments from Xenopus egg extracts, which contain abundant disassembled nuclear pores. Strikingly, Nup98 and Nup153 each bound the same four large proteins. Purification and sequence analysis revealed that two are the known vertebrate nucleoporins, Nup96 and Nup107, whereas two mapped to ORFs of unknown function. The genes encoding the novel proteins were cloned, and antibodies were produced. Immunofluorescence reveals them to be new nucleoporins, designated Nup160 and Nup133, which are accessible on the basket side of the pore. Nucleoporins Nup160, Nup133, Nup107, and Nup96 exist as a complex in Xenopus egg extracts and in assembled pores, now termed the Nup160 complex. Sec13 is prominent in Nup98 and Nup153 pulldowns, and we find it to be a member of the Nup160 complex. We have mapped the sites that are required for binding the Nup160 subcomplex, and have found that in Nup98, the binding site is used to tether Nup98 to the nucleus; in Nup153, the binding site targets Nup153 to the nuclear pore. With transfection and in vivo transport assays, we find that specific Nup160 and Nup133 fragments block poly[A]+ RNA export, but not protein import or export. These results demonstrate that two novel vertebrate nucleoporins, Nup160 and Nup133, not only interact with Nup98 and Nup153, but themselves play a role in mRNA export.

Decomposition of the modulated waves in a rotating couette system.

The time-dependent velocity field in a rotating Couette system has been decomposed. Successive instantaneous velocity profiles were obtained by an ultrasonic Doppler velocity profile method, and the spatiotemporal velocity field had been analyzed by two-dimensional Fourier transform. The Fourier spectrum is depicted by intrinsic peaks, and the velocity field cpan be reconstructed with these peak components only, indicating a successful decomposition of the velocity field. This method shows that the so-called broadband component, which is purely spatiotemporal and attributed to chaos, corresponds to a global motion of the wave propagating from roll to roll.