Low-pressure, water-assisted anatexis of basic dykes in a contact metamorphic aureole, Fuerteventura (Canary Islands): oxygen isotope evidence for a meteoric fluid origin

Migmatites produced by low-pressure anatexis of basic dykes are found in a contact metamorphic aureole around a pyroxenite-gabbro intrusion (PX2), on Fuerteventura. Dykes outside and inside the aureole record interaction with meteoric water, with low or negative δ18O whole-rock values (+0.2 to −3.4‰), decreasing towards the contact. Recrystallised plagioclase, diopside, biotite and oxides, from within the aureole, show a similar evolution with lowest δ18O values (−2.8, −4.2, −4.4 and −7.6‰, respectively) in the migmatite zone, close to the intrusion. Relict clinopyroxene phenocrysts preserved in all dykes, retain typically magmatic δ18O values up to the anatectic zone, where the values are lower and more heterogeneous. Low δ18O values, decreasing towards the intrusion, can be ascribed to the advection of meteoric water during magma emplacement, with increasing fluid/rock ratios (higher dyke intensities towards the intrusion acting as fluid-pathways) and higher temperatures promoting increasing exchange during recrystallisatio

Increasing the time resolution of a pulse width modulator in a class D power amplifier by using delay lines

In this paper, we present a method to increase the time resolution of a pulse width modulator by using delay lines. The modulator is part of an open loop class D power amplifier, which uses the ZePoC algorithm to code the audio signal which is amplified in the class D power stage. If the time resolution of the pulse width modulator is high enough, ZePoC could also be used to build an high accuracy AC power standard, because of its open loop property. With the presented method the time resolution theoretically could be increased by a factor of 16, which means here the time resolution will be enhanced from 5 ns to 312.5 ps

RNA integrity in post-mortem samples: influencing parameters and implications on RT-qPCR assays

Abstract Messenger RNA (mRNA) profiling in postmortem human tissue might reveal information about gene expression at the time point of death or close to it. When working with post-mortem human tissue, one is confronted with a natural RNA degradation caused by several parameters which are not yet fully understood. The aims of the present study were to analyse the influence of impaired RNA integrity on the reliability of quantitative gene expression data and to identify ante-and post-mortem parameters that might lead to reduced RNA integrities in post-mortem human brain, cardiac muscle and skeletal muscle tissues. Furthermore, this study determined the impact of several parameters like type of tissue, age at death, gender and body mass index (BMI), as well as duration of agony, cause of death and post-mortem interval on the RNA integrity. The influence of RNA integrity on the reliability of quantitative gene expression data was analysed by generating degradation profiles for three gene transcripts. Based on the deduced cycle of quantification data, this study shows that reverse transcription quantitative polymerase chain reaction (RT-qPCR) performance is affected by impaired RNA integrity. Depending on the transcript and tissue type, a shift in cycle threshold values of up to two cycles was observed. Determining RNA integrity number of 136 post-mortem samples revealed significantly different RNA qualities among the three tissue types with brain revealing significantly lower integrities compared to skeletal and cardiac muscle. The body mass index was found to influence RNA integrity in skeletal muscle tissue (M. iliopsoas). Samples originating from deceased with a BMI>25 were of significantly lower integrity compared to samples from normal weight donors. Correct data normalisation was found to partly diminish the effects caused by impaired RNA quality. Nevertheless, it can be concluded that in post-mortem tissue with low RNA integrity numbers, the detection of large differences in gene expression activities might still be possible, whereas small expression differences are prone to misinterpretation due to degradation. Thus, when working with post-mortem Electronic supplementary material The online version of this articl

A novel ZePoC encoder for sinusoidal signals with a predictable accuracy for an AC power standard

In this paper we present an analytical formulation of a Zero Position Coding (ZePoC) encoder for an AC power standard based on class-D topologies. For controlling a class-D power stage a binary signal with special spectral characteristics will be generated by this ZePoC encoder for sinusoidal signals. These spectral characteristics have a predictable accuracy within a separated baseband to keep the noise floor below a specified level. Simulation results will validate the accuracy of this novel ZePoC encoder. For a real-time implementation of the encoder on a DSP/FPGA hardware architecture a trade-off between accuracy and speed of the ZePoC algorithm has to be made. Therefore the numerical effects of different floating point formats will be analyzed. © 2015 Author(s)

Exploring the thermomechanical properties of peroxide/co-agent assisted thermoplastic vulcanizates through temperature scanning stress relaxation measurements

Temperature scanning stress relaxation (TSSR) measurement of peroxide vulcanized polymer blends of polypropylene (PP) and ultrahigh molecular-EPDM (UHM-EPDM) rubber has been performed to study the thermomechanical behavior of thermoplastic vulcanizates (TPVs). Co-agents play crucial roles in the enhancement of properties of TPVs. Different types of co-agents (Triallyl cyanurate-TAC; N, N-m-phenylene-dimaleimide-HVA2; zinc dimethacrylate-ZDMA; and in-situ formed zinc dimethacrylate-ZMA) have been explored in this work. TSSR study shows that higher T50 and T90 values have been achieved in ZMA co-agent assisted-TPV. Higher TSSR-index (RI) value was also found for the same co-agent ZMA, indicating higher elastic behavior. TSSR result supports the mechanical and rheological properties, and it is found that the ZMA and ZDMA show higher mechanical strength. Cross-linked-density calculated by modified Flory–Rehner equation and the cross-link-density as obtained from TSSR method have been compared and the trend was found to be the same. Stress relaxation study shows the slow relaxation-phenomena of the ZMA-TPV with slowest relaxation-time (θr) than the other TPVs, which correlates with superior material strength. Thermogravimetric analysis proves that there is a difference in degradation temperature of the blends at approximately 5–10°C. Ultrahigh molecular weight-EPDM/PP based TPVs reveal superior thermomechanical and physico-mechanical properties with ZMA and ZDMA co-agent over TAC and HVA2. These ultrahigh molecular weight-EPDM based TPVs can be used in automotive seals/strips, hoses, bellows, and 2 K-molds for automotive applications

Formation of chlorite during thrust fault reactivation. Record of fluid origin and P-T conditions in the Monte Perdido thrust fault (southern Pyrenees)

The chemical and isotopic compositions of clay minerals such as illite and chlorite are commonly used to quantify diagenetic and low-grade metamorphic conditions, an approach that is also used in the present study of the Monte Perdido thrust fault from the South Pyrenean fold-and-thrust belt. The Monte Perdido thrust fault is a shallow thrust juxtaposing upper Cretaceous-Paleocene platform carbonates and Lower Eocene marls and turbidites from the Jaca basin. The core zone of the fault, about 6m thick, consists of intensely deformed clay-bearing rocks bounded by major shear surfaces. Illite and chlorite are the main hydrous minerals in the fault zone. Illite is oriented along cleavage planes while chlorite formed along shear veins (<50μm in thickness). Authigenic chlorite provides essential information about the origin of fluids and their temperature. δ18O and δD values of newly formed chlorite support equilibration with sedimentary interstitial water, directly derived from the local hanging wall and footwall during deformation. Given the absence of large-scale fluid flow, the mineralization observed in the thrust faults records the P-T conditions of thrust activity. Temperatures of chlorite formation of about 240°C are obtained via two independent methods: chlorite compositional thermometers and oxygen isotope fractionation between cogenetic chlorite and quartz. Burial depth conditions of 7km are determined for the Monte Perdido thrust reactivation, coupling calculated temperature and fluid inclusion isochores. The present study demonstrates that both isotopic and thermodynamic methods applied to clay minerals formed in thrust fault are useful to help constrain diagenetic and low-grade metamorphic condition

The Impact of Olfactory Disorders in the United Kingdom

Olfactory disorders are believed to affect 5% of the general population and have been shown to bear significant psychosocial consequences to sufferers. Although more common than blindness and profound deafness in the United Kingdom, the impact of these disorders has not been assessed to date and the plight of British patients has yet to be quantified. In 2012, a patient support organization, Fifth Sense, was founded to provide information and support to sufferers of chemosensory disorders. Following a recent members conference, a survey of the membership was conducted anonymously using a series of questions based on an existing olfactory disorders questionnaire. From 496 respondents, this has demonstrated high rates of depression (43%) and anxiety (45%), impairment of eating experience (92%), isolation (57%), and relationship difficulties (54%). Women appear to have significantly more issues than men in terms of social and domestic dysfunction relating to olfactory loss (P = 0.01). Qualitative disorders also affected more than 1 in 5 members with parosmia reported in 19% and phantosmia in 24%. This paper discusses the details of the British story of anosmia and other related disorders as depicted by those most affected

Interaction of rat alveolar macrophages with dental composite dust

Background: Dental composites have become the standard filling material to restore teeth, but during the placement of these restorations, high amounts of respirable composite dust (<5 mu m) including many nano-sized particles may be released in the breathing zone of the patient and dental operator. Here we tested the respirable fraction of several composite particles for their cytotoxic effect using an alveolar macrophage model system. Methods: Composite dust was generated following a clinical protocol, and the dust particles were collected under sterile circumstances. Dust was dispersed in fluid, and 5-mu m-filtered to enrich the respirable fractions. Quartz DQ12 and corundum were used as positive and negative control, respectively. Four concentrations (22.5 mu g/ml, 45 mu g/ml, 90 mu g/ml and 180 mu g/ml) were applied to NR8383 alveolar macrophages. Light and electron microscopy were used for subcellular localization of particles. Culture supernatants were tested for release of lactate dehydrogenase, glucuronidase, TNF-alpha, and H2O2. Results: Characterization of the suspended particles revealed numerous nano-sized particles but also many high volume particles, most of which could be removed by filtering. Even at the highest concentration (180 mu g/ml), cells completely cleared settled particles from the bottom of the culture vessel. Accordingly, a mixture of nano- and micron-scaled particles was observed inside cells where they were confined to phagolysosomes. The filtered particle fractions elicited largely uniform dose-dependent responses, which were elevated compared to the control only at the highest concentration, which equaled a mean cellular dose of 120 pg/cell. A low inflammatory potential was identified due to dose-dependent release of H2O2 and TNF-alpha. However, compared to the positive control, the released levels of H2O2 and TNF-alpha were still moderate, but their release profiles depended on the type of composite. Conclusions: Alveolar macrophages are able to phagocytize respirable composite dust particle inclusive nanoparticles. Since NR8383 cells tolerate a comparatively high cell burden (60 pg/cell) of each of the five materials with minimal signs of cytotoxicity or inflammation, the toxic potential of respirable composite dust seems to be low. These results are reassuring for dental personnel, but more research is needed to characterize the actual exposure and uptake especially of the pure nano fraction

Interaction of rat alveolar macrophages with dental composite dust

Background: Dental composites have become the standard filling material to restore teeth, but during the placement of these restorations, high amounts of respirable composite dust (<5 mu m) including many nano-sized particles may be released in the breathing zone of the patient and dental operator. Here we tested the respirable fraction of several composite particles for their cytotoxic effect using an alveolar macrophage model system. Methods: Composite dust was generated following a clinical protocol, and the dust particles were collected under sterile circumstances. Dust was dispersed in fluid, and 5-mu m-filtered to enrich the respirable fractions. Quartz DQ12 and corundum were used as positive and negative control, respectively. Four concentrations (22.5 mu g/ml, 45 mu g/ml, 90 mu g/ml and 180 mu g/ml) were applied to NR8383 alveolar macrophages. Light and electron microscopy were used for subcellular localization of particles. Culture supernatants were tested for release of lactate dehydrogenase, glucuronidase, TNF-alpha, and H2O2. Results: Characterization of the suspended particles revealed numerous nano-sized particles but also many high volume particles, most of which could be removed by filtering. Even at the highest concentration (180 mu g/ml), cells completely cleared settled particles from the bottom of the culture vessel. Accordingly, a mixture of nano- and micron-scaled particles was observed inside cells where they were confined to phagolysosomes. The filtered particle fractions elicited largely uniform dose-dependent responses, which were elevated compared to the control only at the highest concentration, which equaled a mean cellular dose of 120 pg/cell. A low inflammatory potential was identified due to dose-dependent release of H2O2 and TNF-alpha. However, compared to the positive control, the released levels of H2O2 and TNF-alpha were still moderate, but their release profiles depended on the type of composite. Conclusions: Alveolar macrophages are able to phagocytize respirable composite dust particle inclusive nanoparticles. Since NR8383 cells tolerate a comparatively high cell burden (60 pg/cell) of each of the five materials with minimal signs of cytotoxicity or inflammation, the toxic potential of respirable composite dust seems to be low. These results are reassuring for dental personnel, but more research is needed to characterize the actual exposure and uptake especially of the pure nano fraction

Postnatal parental smoking: an important risk factor for SIDS

Background: Sudden infant death syndrome (SIDS) is the unexpected death of an infant that remains unexplained after a thorough investigation of the circumstances, family history, paediatric investigation and complete autopsy. In Western society, it is the leading cause of post-neonatal death below 1 year of age. In the Netherlands, the SIDS incidence is very low, which offers opportunities to assess the importance of old and new environmental risk factors. For this purpose, cases were collected through pathology departments and the working group on SIDS of the Dutch Paediatrician Foundation. A total of 142 cases were included; these occurred after the parental education on sleeping position (1987), restricted to the international age criteria and had no histological explanation. Age-matched healthy controls (N∈=∈2,841) came from a survey of the Netherlands Paediatric Surveillance Unit, completed between November 2002 and April 2003. A multivariate analysis was performed to determine the risk factors for SIDS, including sleeping position, antenatal maternal smoking, postnatal parental smoking, premature birth, gender, lack of breastfeeding and socio-economic status. Postnatal smoking was identified as an important environmental risk factor for SIDS (OR one parent∈=∈2.5 [1.2, 5.0]; both parents∈=∈5.77 [2.2, 15.5]; maternal∈=∈2.7 [1.0, 6.4]; paternal∈=∈2.4 [1.3, 4.5] ) as was prone sleeping (OR put prone to sleep∈=∈21.5 [10.6, 43.5]; turned prone during sleep∈=∈100 [46, 219]). Premature birth was also significantly associated with SIDS (OR∈=∈2.4 [1.2, 4.8]). Conclusion: Postnatal parental smoking is currently a major environmental risk factor for SIDS in the Netherlands together with the long-established risk of prone sleeping