Subducted organic matter buffered by marine carbonate rules the carbon isotopic signature of arc emissions.

Ocean sediments consist mainly of calcium carbonate and organic matter (phytoplankton debris). Once subducted, some carbon is removed from the slab and returns to the atmosphere as CO2 in arc magmas. Its isotopic signature is thought to reflect the bulk fraction of inorganic (carbonate) and organic (graphitic) carbon in the sedimentary source. Here we challenge this assumption by experimentally investigating model sediments composed of 13C-CaCO3 + 12C-graphite interacting with water at pressure, temperature and redox conditions of an average slab-mantle interface beneath arcs. We show that oxidative dissolution of graphite is the main process controlling the production of CO2, and its isotopic composition reflects the CO2/CaCO3 rather than the bulk graphite/CaCO3 (i.e., organic/inorganic carbon) fraction. We provide a mathematical model to relate the arc CO2 isotopic signature with the fluid-rock ratios and the redox state in force in its subarc source.

Silicate dissolution boosts the CO2 concentrations in subduction fluids.

Estimates of dissolved CO2 in subduction-zone fluids are based on thermodynamic models, relying on a very sparse experimental data base. Here, we present experimental data at 1-3 GPa, 800 °C, and ∆FMQ ≈ -0.5 for the volatiles and solute contents of graphite-saturated fluids in the systems COH, SiO2-COH ( + quartz/coesite) and MgO-SiO2-COH ( + forsterite and enstatite). The CO2 content of fluids interacting with silicates exceeds the amounts measured in the pure COH system by up to 30 mol%, as a consequence of a decrease in water activity probably associated with the formation of organic complexes containing Si-O-C and Si-O-Mg bonds. The interaction of deep aqueous fluids with silicates is a novel mechanism for controlling the composition of subduction COH fluids, promoting the deep CO2 transfer from the slab-mantle interface to the overlying mantle wedge, in particular where fluids are stable over melts.Current estimates of dissolved CO2 in subduction-zone fluids based on thermodynamic models rely on a very sparse experimental data base. Here, the authors show that experimental graphite-saturated COH fluids interacting with silicates at 1-3 GPa and 800 °C display unpredictably high CO2 contents.

Neonatal protection and preterm birth reduction following maternal group B streptococcus vaccination in a mouse model.

PURPOSE: Evaluate effects of maternal immunization in a mouse model of Group B Streptococcus (GBS) vaginal colonization using clinical isolates. MATERIALS AND METHODS: Female pregnant mice were immunized with heat-killed GBS 21 days before pregnancy and were inoculated intravaginally with GBS cultures (5 × 107 CFU twice a day for three days) from the 16th day of pregnancy. Gestation period and mice survival were monitored. Maternal anti-GBS IgG levels have been determined by ELISA analysis in vaccinated, unvaccinated mothers and newborns. RESULTS: Maternal immunization before pregnancy provided protection to newborns for three of the four GBS strains used. Evaluation of the immunogenicity showed that this vaccination induced higher levels of IgG in vaccinated compared to unvaccinated dams and the presence of antibodies in the offspring at embryonic and postnatal age, and a Th1 response and high levels of IgG2a subclass antibody and IFN-γ were detected. A significant reduction of preterm births was observed in vaccinated mothers (p< 0.05). CONCLUSIONS: Our finding suggest that vaccinated mothers could protect their progeny from GBS infection and preterm birth through passive immunization. The proposed mouse model may represent a noninvasive and effective tool to investigate pathogenetic mechanisms of GBS ascending infection and for vaccine protection studies.

Evaluation of the Two-Dimensional Performances of Low Activity Planar Catalysts: Development and Validation of a True Scanning Reactor.

The development of a scanning reactor for planar catalysts is presented here. With respect to other existing models, this reactor is able to scan catalysts even with low turnover frequencies with a minimum sensed circular area of approximately 6 mm in diameter. The downstream gas analysis is performed with a quaprupole mass spectrometer. The apparatus performances are presented for two different reactions: the hydrogenation of butadiene over palladium films and the oxidation of CO over a gold/titania catalyst. With the final setup, true scans in both X and Y directions (or even in a previously defined complex directional pattern) are possible within a scan speed ranging from 0.1 to 5.0 mm/min. Finally, this apparatus aims at becoming a valuable tool for high throughput and combinatorial experimentation to test patterned active surfaces and catalytic libraries.

Behavioral and neurophysiological investigation of the influence of verbal suggestion on tactile perception.

Recently we demonstrated that it is possible to influence tactile perception by applying a placebo manipulation consisting of verbal suggestion and conditioning and that this influence is associated to changes in the late components (N140 and P200) of somatosensory-evoked potentials (SEPs) (Fiorio et al., 2012). Due to the powerful effects of words in changing symptoms perception in the clinical domain, aim of this study was to investigate whether even in the tactile modality, perception can be changed by the mere use of persuasive words in a specific context. To this purpose, we adopted the same experimental setting of our previous study, apart from the conditioning procedure. A group of subjects (experimental group) has been verbally suggested about the effect of an inert cream in enhancing tactile perception, while a control group was informed about the inefficacy of the cream. In order to unveil the neurophysiological underpinnings of this effect, we compared the amplitude of late SEPs (P100, N140, P200), before and after treatment. Results showed that the experimental group did not perceive an increase of tactile sensation after the treatment and no modification occurred in the late SEPs. This study proves that verbal suggestion alone is not sufficient to induce enhanced tactile perception (at least with this experimental setting), suggesting that a conditioning procedure may be necessary in the tactile modality. The absence of changes in the late SEP components could reflect the lack of strong expectation following the placebo procedure.

Enhancing non-noxious perception: behavioural and neurophysiological correlates of a placebo-like manipulation.

Sensory perception can be influenced by cognitive functions like attention and expectation. An emblematic case of this is the placebo effect, where a reduction in pain perception can be obtained by inducing expectation of benefit following a treatment. The current study assessed the behavioural and brain activity correlates of a placebo procedure inducing an enhancement of non-noxious somatic sensation. An experimental group was verbally suggested and surreptitiously conditioned about the effect of an inert cream in enhancing tactile perception, while a control group was informed about the actual inefficacy of the cream. Both groups received non-noxious electric shocks activating A-Beta fibres on the right index finger, before and after application of the cream in the same site. The behavioural and neurophysiological effects of this procedure were measured by a numerical rating scale of subjective perception and by recording cortical and subcortical somatosensory-evoked potentials (SEPs). Although the intensity of stimulation was physically identical in the two sessions, the experimental group reported stronger tactile sensation after cream treatment than before. In parallel, the experimental group showed enhanced somatosensory cortical responses (N140, P200) after treatment, whereas subcortical and early-cortical SEP components did not change. We suggest that these findings reflect top-down modulation on tactile perception probably due to an interplay between expectation and attention and might rely on interactions between prefrontal and parietal brain regions.

Identification and molecular characterization of a S. agalactiae strain lacking the capsular locus.

During a national surveillance program on Group B streptococci (GBS) maternal carriage and neonatal infections, a GBS strain isolated from a pregnant woman's vagino-rectal swab was non typable by either serological or molecular methods. Further molecular characterization demonstrated that the strain lacked the entire capsular locus, possibly by a recombination event that excised a 14,1 Kbase pairs genomic fragment extending from the regulatory protein cpsX gene to the neuA gene. The natural loss of the capsular locus by GBS isolated from a human has never been described so far. Such an event, while possibly a dead-end from the evolutionary point of view, leaves a still able-to-colonize organism unrecognizable by the vaccines currently under development.

[French validation of the anger reactions and goals scale (RBC)]. / Validation française de l'échelle des réactions et des buts liés à la colère (RBC).

BACKGROUND: The study presents the French validation of a German scale (AERZ) [Diagnostica 49 (2003) 97-109, revised Eur J Pers (2009)] measuring anger regulation. The French validation (RBC scale) comprises two subscales measuring seven anger reactions and seven anger goals. Disentangling dimensions related to anger reactions and anger goals, respectively, is the main advantage of this scale. In addition to seven cognitive-behavioral anger reactions (i.e., venting, rumination, submission, feedback, distraction, humor and downplaying the incident's negative impact), the RBC scale also addresses the cognitive representations underlying anger reactions by exploring anger goals (i.e., enforcing personal standards, enforcing social standards, downregulating affect, avoiding conflicts, protecting one's reputation, weighing costs and gaining revenge). METHOD: The original scale was translated following the scientific guidelines and recommendations for cultural adaptation of instruments. The adapted French version was tested with a sample of students (n=184, 70.7% were females) from the University of Luxembourg (M=21.31, S.D.=1.93). Students filled in a questionnaire composed of the RBC scale, the SF-36 quality of life scale and the STAXI-II anger instrument. The RBC scale comprises 56 items; reactions are assessed on a 4 point Likert scale from "almost never" (1) to "always" (4), whereas goals are assessed on a 4 point Likert scale from "not at all" (1) to "completely" (4). RESULTS: Factor analysis revealed a seven-factor solution for the anger reactions subscale (that explained 63.13% of the common variance) and a six-factor solution for the anger goals subscale (that explained 57.45% of the common variance). The original factorial structure was examined in confirmatory factor analysis. For the anger reactions subscale, a good model fit was found, with chi(2)(329)=546.38, p<0.1, CFI=0.87, RMSEA=0.06. For the anger goals subscale, a satisfactory model fit was observed, with chi(2)(335)=658.52, p<0.1, CFI=0.78, RMSEA=0.07 revealing a six-factorial structure that differed from the original version in the combination of two dimensions ("downregulating affect" and "protecting one's reputation"). The RBC scale's internal consistencies were found satisfactory with Cronbach's alphas ranging from 0.60 to 0.83 for the various dimensions. Part-whole correlations ranged from r(it)=0.27 to 0.80. Gender differences showed that female participants used significantly more rumination strategies and emotional regulation, whereas male students demonstrated greater humor in anger situations. Significant correlations between RBC and STAXI-II confirmed the construct validity of the RBC scale. Criteria validity was analyzed using the predictive value of the RBC dimensions on the quality of life subscales of the SF-36. CONCLUSION: The present results support the validity, the reliability and the sensitivity of the 56 items scale on anger regulation and its use in psychological research. Although our findings need to be replicated and the test-retest validity is subject to future verification, the present validation of the RBC scale offers a multidimensional inventory for measuring anger reactions and anger goals. This inventory may be used, for example, as a diagnostic tool or for testing the effectiveness of anger management interventions.

Validation of an isotope dilution, ICP-MS method based on internal mass bias correction for the determination of trace concentrations of Hg in sediment cores.

The development and validation of a method for the determination of mercury in sediments using a sector field inductively coupled plasma mass spectrometer (SF-ICP-MS) for detection is described. The utilization of isotope dilution (ID) calibration is shown to solve analytical problems related to matrix composition. Mass bias is corrected using an internal mass bias correction technique, validated against the traditional standard bracketing method. The overall analytical protocol is validated against NRCC PACS-2 marine sediment CRM. The estimated limit of detection is 12ng/g. The proposed procedure was applied to the analysis of a real sediment core sampled to a depth of 160m in Lake Como, where Hg concentrations ranged from 66 to 750ng/g.

Virulence factors in enterococcal infections of orthopedic devices.

Enterococci are opportunistic pathogens which today represent one of the leading causes of nosocomial infections. We have examined a collection of 52 Enterococcus faecalis isolated from orthopedic infections to determine if they were characterized by a specific pattern of virulence factors. The isolates were evaluated for biofilm formation, presence of genes coding the enterococcal surface protein (esp) and gelatinase (gelE), as well as for gelatinase production. While the rate of esp-positive isolates was comparable to that found among strains from other clinical sources, we found a significantly higher rate of strong biofilm formers and gelatinase producers. Particularly high was the rate of gelE-carrying strains expressing the gene. Data suggest that these two factors in particular may play an important role in enterococcal infections associated with biomaterials.

Fast transient infrared studies in material science: development of a novel low dead-volume, high temperature DRIFTS cell.

A prototype DRIFTS flow reaction chamber was designed and developed in order to find analytical application in the study of heterogeneous catalysts operating at high temperatures under fast transient gas feed conditions. Minimisation of dead-volumes allows gas replacement in 8-10s at 10mLmin(-1) total flow. To overcome problems related to the reactivity of the cell walls under alternating oxidizing/reducing gases, the cell was built with Inconel 600trade mark, which was tested to be very inert even at high temperatures. The sample holder, which was developed to closely resemble a micro plug-flow reactor, poses some problems in terms of heat transfer to the outer body of the cell (limiting then the maximum reachable temperature) and of the correct measurement of the actual sample temperature. These problems were solved with a careful re-design of the upper part of the cell. The second prototype thus derived is able to reach temperatures up to 803K and allows gas replacement in less than 4s at 10mLmin(-1). The cell is inserted in a MCT-FT-IR, which allows to collect high quality spectra with a 1s time-resolution. The downstream flow can be analysed by a quadrupole mass spectrometer equipped with an enclosed source and by a commercial GC. The performances of this prototype cell are presented showing some tests carried out with ceria-zirconia (Ce(x)Zr(1-x)O(2)) catalysts for CO abatement under real operando conditions.

On the effect of catalyst status in the quantitative determination of platinum in Pt-Sn/MgO materials.

The development of an analytical method for the determination of platinum in MgO based Pt/Sn catalysts is described. Electrothermal atomic absorption spectroscopy (ETAAS) was chosen because of its high sensitivity and robustness against spectral interferences. All the sources of chemical interferences were statistically analyzed and corrections were adopted for the presence of magnesium oxide support. The effectiveness of different mineralization procedures was critically evaluated as a function of the chemical of the solid catalyst. Microwave digestion allowed recovery of metal of 100% for all the catalysts analyzed and exhibited significant better precision values than other digestion methods, which could nevertheless be utilized under proper conditions in selected cases.

Antibiotic susceptibility and serotype distribution of Streptococcus pneumoniae causing meningitis in Italy, 1997-1999.

Because few data are available in Italy regarding antimicrobial susceptibility and serotype distribution of invasive Streptococcus pneumoniae strains, meningeal isolates collected at Italian hospitals during the years 1997-1999 were studied. The 12 most common serogroups, representing > 85% of the isolates, were 14, 23, 6, 4, 3, 9, 19, 8, 1, 12, 18, and 7 (in order of frequency). The serogroups identified in children < 5 years old were more limited in number: 80% are included in the 7-valent conjugate vaccines. Penicillin resistance was observed in 14 (9.5%) of 148 strains and increased from 5% in the first part of the study to 13% in the last part. Only 2 strains were fully penicillin resistant, and these belonged to serotype 9V. Thirty percent of the strains, mostly belonging to serogroups 14 or 6 and carrying either the ermB or the mef genes, were resistant to erythromycin.

Synthetic oligodeoxynucleotide containing CpG motif induces an anti-polysaccharide type 1-like immune response after immunization of mice with Haemophilus influenzae type b conjugate vaccine.

Synthetic oligodeoxynucleotides containing CpG motifs [immunostimulatory sequences (ISS)] have been described as potent adjuvants of type 1 immune responses when co-administered with protein or peptide vaccines. To investigate their role in the immune response to polysaccharides (CHO), different preparations of anti-Haemophilus influenzae type b (Hib) conjugate vaccine were administered to mice. The unconjugated CHO did not induce the synthesis of specific antibodies even in the presence of ISS. On the other hand, anti-CHO-specific antibodies significantly increased in the presence of ISS, when tetanus (TT) or diphtheria [cross-reacting material (CRM)] toxoid-conjugated CHO were used to immunize mice. The adjuvant effect was also observed for the immune response against the carrier protein (TT and CRM). ISS insured an early and long-lasting specific IgG production. The effects of ISS on the anti-CHO immune response could be attributed to the amplification of the T help provided by the carrier. The analysis of anti-CHO IgG subclasses showed a significant increase of IgG2a and IgG3 in the presence of ISS. ISS caused a rapid release of IL-12 and IFN-gamma in sera from treated mice. This data provide a first evidence for the ability of ISS to induce an anti-CHO type 1-like immune response and demonstrate that ISS have the potential to increase host antibody response against both the CHO and the protein component of a conjugated vaccine.

A routine high-performance size-exclusion chromatography to determine molecular size distribution of Haemophilus influenzae type b conjugate vaccines.

High-performance size exclusion chromatography has been used to determine the molecular size distribution of Haemophilus influenzae type b (Hib) conjugate vaccines. Both high molecular weight preparations of native Hib capsular polysaccharide coupled to tetanus toxoid and low molecular weight vaccines with Hib oligosaccharides linked to the CRM197 nontoxic mutant diphtheria protein were analysed. Columns with different fractionation ranges were used for the two kinds of vaccines. This method showed to be rapid, accurate and reproducible for different lots of Hib vaccine of different composition produced by various manufacturers. It could replace more time-consuming chromatographic methods enabling control authorities to employ a single methodological approach for different Hib vaccines.

Day Bed Unit at the Department of Gastro-enterology. Experience of a study group.

Day Bed Unit at the Department of Gastroenterology. Experience of a study group. We analyzed the activity of the Day-Bed Unit at the Department of Gastroenterology of Turin Hospital (Molinette). The quality of the service provided and the days of stay in hospital for each admission were evaluated in terms of cost benefit ratio. The average stay in hospital for each admission was 2.57 days as opposed to 9.3 in the in patient ward. Patients were divided in subsets according to the cause of admission. Stratifying the patients according to diagnosis showed a hospital stay of 2.73 days for liver disease and of 2.81 for pancreas and biliary disease. Among the admissions for liver disease, pre or posttranspiant patients required 2.89 days as opposed to 2.62 days of those who were treated for esophageal varices. Thus, the cause of admission was a factor influencing length of hospital stay. Patients needing non surgical treatment for liver cancer took 2.22 days if treated with percutaneous ethanol injection; those undergoing chemoembolization required 2.93 days. In conclusion, the day bed unit has proven to be able to provide a service with a good cost benefit ratio. Patients admitted to this service may be withdrawn from the waiting list of the in patient ward, thus reducing the waiting time. Optimization of this service needs integration with the surroudings Units within the Department and in the Hospital.

[Groove pancreatitis. A case report of chronic focal pancreatitis]. / La "groove pancreatitis". Descrizione di un caso di pancreatite cronica focale.

The "groove pancreatitis" is a special form of segmental chronic pancreatitis affecting the "groove" between pancreatic head, duodenum and common bile duct. This type of chronic pancreatitis was first described in 1973 and only few cases have been reported in literature. Unlike other forms of chronic pancreatitis, this is often preceded by peptic ulcers, gastric resections or biliary tract diseases; it could be associated with cysts of the duodenal wall and pancreatic cysts. Abdominal pain, vomiting due to duodenal stenosis, obstructive jaundice and weight loss are the most common presenting symptoms. The radiological features show a pancreatic mass similar to a pancreatic head carcinoma and the discrimination of groove pancreatitis from pancreatic carcinoma is often difficult or even impossible in some patients. We describe a case of groove pancreatitis treated with pancreatoduodenectomy, reviewing the clinical and radiological features. We remark that the groove pancreatitis is a disease that must be known and should be considered in the differential diagnosis of pancreatic carcinoma.