The mineral and chemical composition of green glauconitic grains from ODP Site 959 (2100 m water depth) located on the northern flank of the Ivory Coast—Ghana Marginal Ridge was studied. Recurrent winnowing of a 20 m thick Pleistocene succession resulted in a low accumulation rate and stratigraphic hiatuses. The green clay material typically occurs as fillings in the chambers of pelagic foraminifers. The amount of green clay present in sediments older than 1 Ma is small, and greater in younger material. Mud composed of smectite, kaolinite, traces of mica, calcite and quartz was the precursor material that filled the chambers of the foraminifers. Processes at the water-sediment interface slowly modified this composition. Kaolinite was dissolved; smectite lost Al but gained Fe, K and layer charge. In that matrix, the nanocrystals of neoformed smectite are observed. The infrared (IR) spectra showed OH-stretching and bending vibrations due to groups incorporating Fe3+. The spectra are in agreement with the crystallochemical formulae of Fe3+-rich montmorillonite as determined by point-by-point analyses on the neoformed crystallites and on the surrounding matrix. The layer charge in this Fe3+-rich montmorillonite is almost wholly octahedral as shown in crystallochemical formulae and documented independently by a new IR method. The tetrahedral charge appeared when the Fe content increased by > 1.2 Fe per formula unit. With the maturation process, the increased role of the closed layers is observed, with the color of grains becoming greener. We have documented for the first time glauconitization proceeding at a depth of 2100 m at a temperature near 3°C. The most important factors of the process are: accumulation of terrigenous clayey material in the foraminiferal chambers, Fe supply from a nearby continent, and a lengthy residence at the water-sediment interface in the zone of the winnowing and low sediment accumulation rate.

In the copper deposit of Salobo 3A (Brazil), nontronite-like clay samples were found at the bottom of the weathering blanket. Samples were fractionated first by sedimentation and then by a HGMS method. From XRD data, it was found that the samples are essentially smectite with kaolinite in very small quantities. The average structural formula of the smectite, presented in the traditional manner, is:

Chemical analyses show that the smectite samples contain a population of clay particles whose chemistry ranges between a nontronite end-member and an Al-Mg beidellite end-member.

Spectroscopic studies by FTIR, Mössbauer, and ESR show that the three major octahedral cations (Al, Fe, Mg) are present in each octahedral sheet of the smectite, forming a solid solution, and that the chemical trends of the smectite clay detected at a “macroscopic” scale (associated clay particles) can also be observed at the unit cell scale.

Fourier transform infrared (FTIR) spectroscopy investigations in the near infrared (N1R) region of synthetic and natural kaolinites with various octahedral substitutions have been carried out in order to elucidate the relationships between the substituted cations and specific features of the NIR spectra. The combination modes of the OH stretching and bending vibrations characterizing Fe(III), Ga(III) and Cr(III) octahedral substitutions are identified in the NIR region at 4466, 4498 and 4474 cm-1, respectively, and the first overtones of the OH stretching vibrations at 7018, 7018 and 6986 cm-1, respectively. As far as we know, the bands of kaolinites containing Ga(III) or Cr(III) have not been reported yet. For both Ga(III) and Cr(III), the NIR observations explain why the bending vibration bands of AlGaOH and AlCrOH groups are not observed in the middle infrared (MIR) region.

Millimetric to centimetric green grains widespread in pelagic calcareous sediments recovered at a water depth of3000 m near the Costa Rica margin were studied by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. Samples were collected, during the Ticoflux II expedition, from the upper bioturbated part of four sedimentary cores (0.13–3.75 m below seafloor). The sediments are calcareous and siliceous nanofossil oozes (coccoliths, diatoms, radiolarians, etc.).

Green grains show generally a concentric zoning with a green rim in which smectite largely predominates over pyrite and a black core in which pyrite is prevalent. Observations by SEM indicate that this zoning results from a progressive inward alteration and replacement of the accumulations of pyrites by smectites. The high-resolution TEM observations of the smectite-pyrite interfaces suggest that the replacement of pyrites by smectite occurs through a dissolution-precipitation process with the formation of a gel. The pyrite matrix is composed of a huge number of very small (0.5–22 µm) pyrite octahedra, a typical texture resulting from the pyritization of organic material in early diagenetic environments.

The accurate mineralogical and crystal chemical characterization of the smectites indicate that they are Fe3+-montmorillonites (Fe3+-rich smectite with a dominant octahedral charge, rarely recorded in the literature). The formation of such Fe3+-montmorillonites forming green grains could be explained by two successive diagenetic redox stages: (1) reducing stage: early pyritization of the organic matter by microbial reduction within reducing micro-environments; (2) oxidizing stage: Fe3+-montmorillonite crystallized in space liberated after dissolution of pyrite connected with the rebalancing of the redox conditions of the micro-environments with the oxidizing surrounding sediments.

Stevensite-like sauconite, with the general composition: ${\text{Si}}_4\left({\text{Zn}}_{3-x}{\square }_x\right){\text{O}}_{10}{\left(\text{OH}\right)}_2{R}_{2x}^{+}$\$\end{document}, where □ is a vacant site, was synthesized. The objective was to study the possible migration of some cations (Li+ and Zn2+) within such trioctahedral smectites, under heating, following the so-called ‘Hofmann-Klemen’ (HK) effect. The initial gel was divided into five aliquots and placed in teflon-coated hydrothermal reactors with distilled water, and these were hydrothermally treated at 80, 100, 120, 150, and 200°C, respectively, over 30 days. X-ray diffraction (XRD) analysis confirmed that the samples synthesized were smectites. The number of vacant sites (x) per half unit cell (O10(OH)2) ranged from nearly 0 to 0.23 but no simple relationship was established between x and the temperature of synthesis. The samples were Li+- and Zn2+-saturated, and heated overnight at 300°C (HK treatment). Cation exchange capacity measurements were made by Fourier transform infrared spectroscopy (FTIR) on ${\text{NH}}_4^{+}$\$\end{document}-saturated samples. After LiHK treatment, the structural formula of samples could be expressed as: ${\text{Si}}_4{\text{Zn}}_{\left(3-x\right)}{\text{Li}}_x{\text{O}}_{10}{\left(\text{OH}\right)}_2{\text{NH}}_{4x}^{+}$\$\end{document}, while after ZnHK treatment, it could be expressed as: Si4Zn3O10(OH)2. Analysis by XRD and FTIR showed that the samples moved from a Zn-stevensite-like structure to Zn-talc-like structure after treatment with ZnHK. These results are interpreted asevidence that Zn2+ (and Li+) migrated into the previously vacant sites under HK treatment.

A Mg-rich palygorskite sample from phosphorite deposits of Ganntour (Morocco) with the structural formula ${\text{Si}}_8\left({\text{Mg}}_{2.6}{\text{Al}}_{1.19}{\text{Fe}}_{\text{0.33}}^{\text{III}}{\square }_{0.88}\right){\text{Ca}}_{0.056}{\text{Na}}_{0.024}{\text{K}}_{0.104}{\text{O}}_{20}{\left(\text{OH}\right)}_2{\left({\text{OH}}_2\right)}_{4\cdot }4{\text{H}}_2\text{O}$, was studied by FTIR spectroscopy. In both OH-stretching and OH-bending regions, there is evidence of dioctahedral Al2□OH, AlFe□OH and trioctahedral Mg3OH features, leading to a di-trioctahedral crystallochemical model of octahedral site occupancies in ribbons of Ganntour palygorskite.

This model, established through the IR spectroscopy study of a Mg-rich palygorskite, seems to be appropriate for many other palygorskites with lower Mg content in the octahedral sheet.

The generation of liquid jets and drops using tightly focused femtosecond laser pulses near a liquid–air interface is a convenient contactless solution for printing functional materials as well as bio-materials. Jets and drops emerge following the nucleation of a cavitation bubble in the liquid bulk by a laser-induced plasma. During the initial expansion of the bubble, a thin and fast jet is produced at the liquid surface. Moments later a second thick and slow jet emanates from the surface when the bubble has nearly deflated. Despite potential applications, little is known about the mechanism behind this complex phenomenology. Here, experiments and simulations are used to investigate this two-jet process. Counter-intuitively, the second jet is not the result of bubble expansion, as with the first jet, but originates from the secondary flows induced by the bubble dynamics. Our study links the second jet properties to the control parameters of the problem and establishes a phase diagram for its emergence.

We summarize a series of numerical experiments of collisional dynamics in dense stellar systems such as globular clusters (GCs) and in weakly collisional plasmas using a novel simulation technique, the so-calledMulti-particle collision (MPC) method, alternative to Fokker-Planck and Monte Carlo approaches. MPC is related to particle-mesh approaches for the computation of self consistent long-range fields, ensuring that simulation time scales with N log N in the number of particles, as opposed to N2 for direct N-body. The collisional relaxation effects are modelled by computing particle interactions based on a collision operator approach that ensures rigorous conservation of energy and momenta and depends only on particles velocities and cell-based integrated quantities.

The stability of symptomatology and of eleven schizophrenic diagnostic systems was studied in patients initially in an acute phase (group 1) compared to patients in a residual phase (group 2). The patients were evaluated over a period of 1 year with a standardized checklist and PANSS in both groups. The number of patients included by the Carpenter, Calego, 1CD9, New-Haven, Schneider and Vienne systems decreased significantly between admission and discharge in group 1, whereas no variation was observed in group 1 between discharge and one year later, or in group 2 over a period of 1 year. The instability of schizophrenic diagnostic systems such as New-Haven, Schneider and Vienne could be due to the variation of positive or general symptomatology. The number of patients included by Feighner or Langfeldt did not vary significantly between admission and discbarge in group 1, in spite of a significant decrease in symptomatology, probably because certain criteria, such as duration of illness, hindered the systems from changing. The results showed the importance of specifying in every study on schizophrenia the time of inclusion (admission, discharge) or the phase of illness (acute or residual phase).

The aim of this study was to test whether a positive and a negative component could be found in broadly defined schizophrenic patients. Therefore, 70 patients either in an exacerbated or in a stabilized phase were selected according to the criteria of at least 1 of the 4 following diagnostic systems: DSM III-R, Schneider, Carpenter, Langfeldt; principal component analyses (PCA) were carried out with the 9 global ratings of the Scales for Assessment of Negative and Positive Symptoms (SANS and SAPS) and with the Positive and Negative Syndrome Scale (PANSS). The PCA of the SANS-SAPS global ratings yielded a 3-factor solution explaining 72.14% of the total variance, depicting a negative, a positive and a disorganization component. The PCA of the PANSS provided a 5-factor solution with a total explained variance of 55.98%. The first 3 factors were similar to those of the SANS-SAPS global rating analysis. The results showed that the positive and negative components described in a homogeneous schizophrenic population could be replicated in a larger and more heterogeneous group of schizophrenic patients. The question regarding the sufficiency of the positive-negative dichotomy was strengthened by the presence of a third disorganization component which explained as much of the variance as the positive component.

Whether studies agree or disagree on the positive-negative dichotomy in schizophrenia, the relevance of a third component, disorganization, remains a point of debate. Disorganization, as expressed by the scale for the assessment of negative symptoms and positive symptoms (SANS-SAPS) and the positive and negative syndrome scale (PANSS) principal-component analyses, could be considered as permanent and determinant a dimension as the positive and negative components. The aim of this study therefore was to determine whether this disorganization, with the negative and positive components, is stable and has the same composition in the acute and postacute phases of illness. This study was carried out in 57 patients, broadly defined by at least one of four diagnostic criteria (American Psychiatric Association, Langfeldt, Carpenter and Schneider), established with a computerized checklist, and evaluated with SANS-SAPS and PANSS. Principal component analyses (PCA) of these scales were performed at admission and discharge from hospital.

The PCA of SANS-SAPS displayed a 3-factor solution, regardless of the phase of illness (acute or postacute), showing that the negative, positive and disorganization components were stable. The PCA of PANSS yielded negative and positive components perfectly stable over time and a disorganization component whose composition varied between admission and discharge. At admission, this component included the conceptual disorganization item negatively correlated with one of depression. At discharge, this disorganization component included two additional items, autistic preoccupation and mannerisms and one depression component appeared. The instability of the PCA of PANSS could express the role played by the phase of illness; in an acute phase, this disorganization component was constituted by more “positive” items such as grandiosity, unusual thought content and active social avoidance whereas in the postacute phase, it included items that reflected more the chronicity of the illness, such as mannerisms and autistic preoccupation. Moreover, the depressive item appeared, in the postacute phase, in a specific depressive component. This result could be due to the fact that depressive symptoms cannot be expressed when positive symptoms are very severe, which explains why no depressive components were shown during the acute phase.

The concordance and degree of overlap between 13 diagnostic systems for schizophrenia, including the five European systems of Berner, Bleuler, Langfeldt, Pull and Schneider, were evaluated in a cross-sectional study (N = 51) taking the phase of illness (acute or residual) into account. The diagnostic assessments were processed by computer using a 183-item standardised checklist and a data-processing program in GW-Basic language. The inter-rater reliability, as assessed by Kappa coefficient, was good to excellent for each diagnostic system established by this method (K from 0.5 to 1). When comparing the concordance between pairs of 13 diagnostic systems for schizophrenia in acute and residual phase groups, results showed that only two significant relationships were not influenced by the phase of illness (Carpenter x RDC; Catego x Schneider), while 24 were. These included only two relationships in the acute group (Carpenter Catego; Carpenter Schneider) and 22 links between pairs of systems in the residual group. In the acute group, no diagnosis of schizophrenia, including duration criteria such as those of DSM III-R, Feighner, Langfeldt, Pull and RDC, was linked to other systems. In the residual group, the operational systems such as Catego, DSM III-R, Feighner, Newhaven, Pull and RDC had more than five relationships with the other systems whereas the non-operational systems of Bleuler, ICD9, Langfeldt and Schneider had less than four relationships with the others. Except Pull's criteria, the European diagnostic systems, in particular Berner's and Bleuler's, seemed to differ from the others because of the few relationships displayed. The results underline the importance of taking the phase of illness into account when comparing between studies utilizing different diagnostic systems for schizophrenia. They also show the relationships between European and international diagnostic systems, insufficiently established so far.

Recently, much effort has been directed towards reaching a consensus on the use of antipsychotic medication in the United Kingdom (UK) and in France. Anecdotal evidence suggests, however, that any differences that may exist between practitioners in the UK are only minor in comparison to those between practitioners in the various countries in the European Union. A comparison was conducted of the number of prescribed antipsychotic compounds, as well as their way of administration, in two samples of schizophrenic patients in the UK and France. French patients were much more likely to have been prescribed two or more antipsychotic compounds, either alone (relative risk: RR = 26.3; 95% CI: 3.8-190.6), or in combination with a depot preparation (RR = ∞; Fisher's exact test P = 0.04). British patients were more likely to have been prescribed a single depot preparation (RR = 4.7; 95% CI: 2.3-9.9). These disparities are related to contrasting views on the properties and indications of antipsychotics in the two countries. Given these disparities, working towards a European consensus appears essential.

The course of negative and positive symptoms was studied in neuroleptic-treated patients over a 3-year period, in consideration also of the initial phase of illness (post-acute or chronic). This study was carried out in a broadly defined schizophrenic sample, in order not to give preference to one diagnostic subgroup over another. Forty-six patients were evaluated every year for 3 years, 23 in the post-acute group and 23 in the chronic group. Aggravations of the Clinical Global Impression (CGI) and of the SANS total score were observed, regardless of the group (chronic or post-acute). This global aggravation confirmed Kraepelin's concept of dementia praecox; moreover, this aggravation was not due to an increase in the number of patients relapsing, or to an aggravation of akinesia. Three types of negative and positive symptom courses were observed: i) the mean sub-scores of positive symptoms, such as hallucinations, delusions, positive formal thought disorders, and of negative symptoms such as flattening affect, avolition/apathy and attentional impairment, did not vary significantly over time in either group; ii) the mean sub-scores of bizarre behavior and alogia fluctuated over time (p < 0.05) and only poverty of speech was perfectly stable among the items constituting alogia; iii) the mean subscores of anhedonia/asociality worsened significantly over time irrespective of the groups (p < 0.05), and among the items constituting anhedonia, recreational interest-activities and intimacy-closeness abilities worsened (p < 0.05 and p < 0.01, respectively). This aggravation was neither due to an increase in neuroleptic doses nor to the duration and chronicity of illness. However, negative symptoms, except anhedonia, can be reversible in some patients. The very strong stability of anhedonia, whatever the group, emphasize the importance of taking anhedonia into account in future diagnostic classifications.