Depositional age, provenance and metamorphic age of metasedimentary rocks from southern Madagascar

Southern Madagascar is the core of a >1 million km(2) Gondwanan metasedimentary belt that forms much of the southern East African Orogen of eastern Africa, Madagascar, southern India and Sri Lanka. Here the Vohibory Series yielded U-Pb isotopic data from detrital zircon cores that indicate that it was deposited in the latest Tonian to late Cryogenian (between -900 and 640 Ma). The deposition of the Graphite and Androyen Series protoliths is poorly constrained to between the late Palaeoproterozoic and the Cambrian (similar to 1830-530 Ma). The Vohibory Series protoliths were sourced from very restricted-aged sources with a maximum age range between 910 and 760 Ma. The Androyen and Graphite Series protoliths were sourced from Palaeoproterozoic rocks ranging in age between 2300 and 1800 Ma. The best evidence of the timing of metamorphism in the Vohibory Series is a weighted mean Pb-206/U-238 age of 642 +/- 8 Ma from 3 analyses of zircon from sample M03-01. A considerably younger Pb-206/U-238 metamorphic age of 531 +/- 7 Ma is produced from 10 analyses of zircon from sample M03-28 in the Androyen Series. This similar to 110 Ma difference in age is correlated with the early East African Orogeny affecting the west of Madagascar along with its type area in East Africa, whereas the Cambrian Malagasy Orogeny affected the east of Madagascar and southern India during the final suturing of the Mozambique Ocean. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Do charges to freight trucks and trains in the European Union reflect their social marginal costs? Application to the case of Spain

In the last few years, the European Union (EU) has become greatly concerned about the environmental costs of road transport in Europe as a result of the constant growth in the market share of trucks and the steady decline in the market share of railroads. In order to reverse this trend, the EU is promoting the implementation of additional charges for heavy goods vehicles (HGV) on the trunk roads of the EU countries. However, the EU policy is being criticised because it does not address the implementation of charges to internalise the external costs produced by automobiles and other transport modes such as railroad. In this paper, we first describe the evolution of the HGV charging policy in the EU, and then assess its practical implementation across different European countries. Second, and of greater significance, by using the case study of Spain, we evaluate to what extent the current fees on trucks and trains reflect their social marginal costs, and consequently lead to an allocative-efficient outcome. We found that for the average case in Spain the truck industry meets more of the marginal social cost produced by it than does the freight railroad industry. The reason for this lies in the large sums of money paid by truck companies in fuel taxes, and the subsidies that continue to be granted by the government to the railroads.

Qualitative analysis by online nuclear magnetic resonance using Carr-Purcell-Meiboom-Gill sequence with low refocusing flip angles

The Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence has been used in many applications of magnetic resonance imaging (MRI) and low-resolution NMR (LRNMR) spectroscopy. Recently. CPMG was used in online LRNMR measurements that use long RF pulse trains, causing an increase in probe temperature and, therefore, tuning and matching maladjustments. To minimize this problem, the use of a low-power CPMG sequence based on low refocusing pulse flip angles (LRFA) was studied experimentally and theoretically. This approach has been used in several MRI protocols to reduce incident RF power and meet the specific absorption rate. The results for CPMG with LRFA of 3 pi/4 (CPMG(135)), pi/2 (CPMG(90)) and pi/4 (CPMG(45)) were compared with conventional CPMG with refocusing pi pulses. For a homogeneous field, with linewidth equal to Delta nu = 15 Hz, the refocusing flip angles can be as low as pi/4 to obtain the transverse relaxation time (T(2)) value with errors below 5%. For a less homogeneous magnetic field. Delta nu = 100 Hz, the choice of the LRFA has to take into account the reduction in the intensity of the CPMG signal and the increase in the time constant of the CPMG decay that also becomes dependent on longitudinal relaxation time (T(1)). We have compared the T(2) values measured by conventional CPMG and CPMG(90) for 30 oilseed species, and a good correlation coefficient, r = 0.98, was obtained. Therefore, for oilseeds, the T(2) measurements performed with pi/2 refocusing pulses (CPMG(90)), with the same pulse width of conventional CPMG, use only 25% of the RF power. This reduces the heating problem in the probe and reduces the power deposition in the samples. (C) 2011 Elsevier B.V. All rights reserved.

Relationship between elastic and mechanical properties of dental ceramics and their index of brittleness

The purpose of the study was to verify the effects of a number of materials' parameters (crystalline content; Young's modulus, E; biaxial flexure strength, sigma(i); Vickers hardness, VH; fracture toughness, K-Ic; fracture surface energy, gamma(f); and index of brittleness, B) on the brittleness of dental ceramics. Five commercial dental ceramics with different contents of glass phase and crystalline particles were studied: a vitreous porcelain (VM7/V), a porcelain with 16 vol% leucite particles (d.Sign/D), a glass-ceramic with 29 vol% leucite particles (Empress/E1), a glass-ceramic with 58 vol% lithium-disilicate needle-like particles (Empress 2/E2), and a glass-infiltrated alumina composite with 65 vol% crystals (In-Ceram Alumina/IC). Discs were constructed according to manufacturers' instructions, ground and polished to final dimensions (12 mm x 1.1 mm). Elastic constants were determined by ultrasonic pulse-echo method. sigma(i) was determined by piston-on-3-balls method in inert condition. VH was determined using 19.6 N load and K-Ic was determined by indentation strength method. gamma(f) was calculated from the Griffith-Irwin relation and B by the ratio of HV to K-Ic. IC and E2 showed higher values of sigma(i), E, K-Ic and gamma(f), and lower values of B compared to leucite-based glass-ceramic and porcelains. Positive correlations were observed for sigma(i) versus K-Ic, and K-Ic versus E-1/2, however, E did not show relationship with HV and B. The increase of crystalline phase content is beneficial to decrease the brittleness of dental ceramics by means of both an increase in fracture surface energy and a lowering in index of brittleness. (C) 2012 Elsevier Ltd and Techna Group Sri. All rights reserved.

Tragedy on grade crossing: driver failure or systemic fragility?

In 2010, an accident occurred in Americana-SP, Brazil, involving two trains and one bus on a Grade Crossing, when 10 people died and 17 were injured including workers. This paper aims to analyze the accident using the Model of Analysis and Prevention of Work Accidents (MAPA). The method provides observation of work, interviews and analysis of documents to understand precedents of the event in the following stages: to understand the usual work from the involved people, the changes occurred in the system, the operation of barriers, managerial and organizational aspects. By the end, measures are suggested to avoid new occurrences. The accident took place at night in a site with insufficient lighting. The working conditions of bus drivers, train operators and watchmen are inadequate. There were only symbolic barriers (visual and acoustic signals) triggered manually by watchman upon train operator radio communication. The fragility of the barrier system associated to poor lighting and short time to trigger the signaling seem to play a critical role in the event. Contrary to the official report which resulted in guilt of the bus driver, the conclusion of the paper emphasizes the fragility of the safety system and the need of level crossing reproject.

Analgesic effects of repetitive transcranial magnetic stimulation of the motor cortex in neuropathic pain: Influence of theta burst stimulation priming

Background Conventional protocols of high-frequency repetitive transcranial magnetic stimulation (rTMS) delivered to M1 can produce analgesia. Theta burst stimulation (TBS), a novel rTMS paradigm, is thought to produce greater changes in M1 excitability than conventional protocols. After a preliminary experiment showing no analgesic effect of continuous or intermittent TBS trains (cTBS or iTBS) delivered to M1 as single procedures, we used TBS to prime a subsequent session of conventional 10?Hz-rTMS. Methods In 14 patients with chronic refractory neuropathic pain, navigated rTMS was targeted over M1 hand region, contralateral to painful side. Analgesic effects were daily assessed on a visual analogue scale for the week after each 10?Hz-rTMS session, preceded or not by TBS priming. In an additional experiment, the effects on cortical excitability parameters provided by single- and paired-pulse TMS paradigms were studied. Results Pain level was reduced after any type of rTMS procedure compared to baseline, but iTBS priming produced greater analgesia than the other protocols. Regarding motor cortex excitability changes, the analgesic effects were associated with an increase in intracortical inhibition, whatever the type of stimulation, primed or non-primed. Conclusions The present results show that the analgesic effects of conventional 10?Hz-rTMS delivered to M1 can be enhanced by TBS priming, at least using iTBS. Interestingly, the application of cTBS and iTBS did not produce opposite modulations, unlike previously reported in other systems. It remains to be determined whether the interest of TBS priming is to generate a simple additive effect or a more specific process of cortical plasticity.

Proinflammatory and Antiinflammatory Cytokine Levels in Complicated and Noncomplicated Parapneumonic Pleural Effusions

Objectives: This study aimed to evaluate a panel of proinflammatory and antiinflammatory cytokines in noncomplicated and complicated parapneumonic pleural effusions and to correlate their levels with pleural fluid biochemical parameters. Methods: Serum and pleural effusion were collected from 60 patients with noncomplicated (n = 26) or complicated (n = 34) parapneumonic effusions and assayed for cytologic, biochemical, and proinflammatory and antiinflammatory cytokines. Student t test was used to compare serum and pleural fluid values, Spearman correlation to analyze the relationship between pleural fluid cytokines and biochemical parameters, and accuracy of pleural fluid cytokine levels to determine the optimal cutoff value for identification of complicated effusions. Corrections for multiple comparisons were applied and a P value < .05 was accepted as significant. Results: Serum and pleural fluid cytokine levels of IL-8, vascular endothelial growth factor (VEGF), IL-10, and tumor necrosis factor (TNF) soluble receptor (sR) II were similar between groups. In contrast, complicated effusions had higher levels of pleural fluid IL-1 beta, IL-1 receptor antagonist (ra), and TNF sRI. Negative correlations were found between pleural fluid glucose with IL-1 beta and TNF sRI and positive correlations between lactic dehydrogenate (LDH) with IL-1 beta, IL-8, and VEGF. Pleural fluid levels of IL-1 beta, IL-1ra, and TNF sRI were more accurate than IL-8, VEGF, IL-10, and TNF sRII in discriminating complicated effusions. Conclusions: Both proinflammatory and antiinflammatory cytokine levels in pleural fluid are elevated in complicated in comparison with noncomplicated parapneumonic pleural effusions, and they correlate with both pleural fluid glucose and LDH levels. IL-1 beta, IL-1ra, and TNF sRI had higher sensitivity and specificity than IL-8, VEGF, IL-10, and TNF sRII in discriminating complicated effusions. CHEST 2012; 141( 1):183-189

Adaptação do aparelho de amplificação sonora no SUS comparado com um modelo de adaptação compacto

In the present days it is critical to identify the factors that contribute to the quality of the audiologic care provided. The hearing aid fitting model proposed by the Brazilian Unified Health System (SUS) implies multidisciplinary care. This leads to some relevant and current questions. OBJECTIVE: To evaluate and compare the results of the hearing aid fitting model proposed by the SUS with a more compact and streamlined care. METHOD: We conducted a prospective longitudinal study with 174 participants randomly assigned to two groups: SUS Group and Streamline Group. For both groups we assessed key areas related to hearing aid fitting through the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire, in addition to evaluating the results of Speech Recognition Index (SRI) 3 and 9 months after fitting. RESULTS: Both groups had the same improvement related to the speech recognition after nine months of AASI use, and the IOI-HA didn't show any statically significant difference on three and nine months. CONCLUSION: The two strategies of care did not differ, from the clinical point of view, as regards the hearing aid fitting results obtained upon the evaluation of patients in the short and medium term, thus changes in the current model of care should be considered.