The Panarea Volcanic Group (PVG) is a group of emergent islands rising from the truncated cone of an underwater edifice in the eastern sector of the Aeolian Island Arc in the Tyrrhenian Sea, Italy. ...Selected lava units from the main island of Panarea and some of the nearby islets were analysed for their major and trace element compositions to the dataset available in the literature. Major mineral phases were identified as plagioclase ± clinopyroxene ± orthopyroxene ± olivine ± amphibole ± mica. The lavas of this study range from andesite to rhyolite with major element compositions equivalent to previously published data. Pyroxene geobarometry suggests a polybaric distribution to crystal fractionation, beginning at the Moho, and continuing to a shallow magma reservoir, at approximately 0.8 km depth. A plot of Nd
143
/Nd
144
vs. Sr
87
/Sr
86
show the compositions of Panarea overlap with the compositions of the eastern and central Aeolian Arc, while Pb
208
/Pb
204
vs. Pb
206
/Pb
204
do not overlap, but fall between the central and eastern arc values. As major and trace element concentrations, and isotope compositions of the lavas of this study overlap most consistently with lava compositions from the central and eastern Aeolian Arc, indicating Panarea should be considered an “intermediate” volcano in the arc.
There is a growing interest in the use of geophysical methods to aid investigation and monitoring of complex biogeochemical environments, for example delineation of contaminants and microbial ...activity related to land contamination. We combined geophysical monitoring with chemical and microbiological analysis to create a conceptual biogeochemical model of processes around a contaminant plume within a manufactured gas plant site. Self‐potential, induced polarization and electrical resistivity techniques were used to monitor the plume. We propose that an exceptionally strong (>800 mV peak to peak) dipolar SP anomaly represents a microbial fuel cell operating in the subsurface. The electromagnetic and electrical geophysical data delineated a shallow aerobic perched water body containing conductive gasworks waste which acts as the abiotic cathode of microbial fuel cell. This is separated from the plume below by a thin clay layer across the site. Microbiological evidence suggests that degradation of organic contaminants in the plume is dominated by the presence of ammonium and its subsequent degradation. We propose that the degradation of contaminants by microbial communities at the edge of the plume provides a source of electrons and acts as the anode of the fuel cell. We hypothesize that ions and electrons are transferred through the clay layer that was punctured during the trial pitting phase of the investigation. This is inferred to act as an electronic conductor connecting the biologically mediated anode to the abiotic cathode. Integrated electrical geophysical techniques appear well suited to act as rapid, low cost sustainable tools to monitor biodegradation.
Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ...ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought.
Regular aspirin use is associated with reduced risk of several malignancies. Epidemiologic studies analyzing aspirin, nonaspirin nonsteroidal anti-inflammatory drug (NSAID), and acetaminophen use and ...ovarian cancer risk have been inconclusive.
We analyzed pooled data from 12 population-based case-control studies of ovarian cancer, including 7776 case patients and 11843 control subjects accrued between 1992 and 2007. Odds ratios (ORs) for associations of medication use with invasive epithelial ovarian cancer were estimated in individual studies using logistic regression and combined using random effects meta-analysis. Associations between frequency, dose, and duration of analgesic use and risk of ovarian cancer were also assessed. All statistical tests were two-sided.
Aspirin use was associated with a reduced risk of ovarian cancer (OR = 0.91; 95% confidence interval CI = 0.84 to 0.99). Results were similar but not statistically significant for nonaspirin NSAIDs, and there was no association with acetaminophen. In seven studies with frequency data, the reduced risk was strongest among daily aspirin users (OR = 0.80; 95% CI = 0.67 to 0.96). In three studies with dose information, the reduced risk was strongest among users of low dose (<100 mg) aspirin (OR = 0.66; 95% CI = 0.53 to 0.83), whereas for nonaspirin NSAIDs, the reduced risk was strongest for high dose (≥500 mg) usage (OR = 0.76; 95% CI = 0.64 to 0.91).
Aspirin use was associated with a reduced risk of ovarian cancer, especially among daily users of low-dose aspirin. These findings suggest that the same aspirin regimen proven to protect against cardiovascular events and several cancers could reduce the risk of ovarian cancer 20% to 34% depending on frequency and dose of use.
We developed a naturalistic behavioral task to investigate the influence of spatial and temporal expectations on attentional orienting to moving targets. In this task, the movement of an object ...before its disappearance under an occluding barrier generated expectations concerning the location and/or time of its reappearance. Four different trial types were intermixed, each inducing a different state of expectation: no expectation, only spatial expectation about the location of reappearance, only temporal expectation about the moment of reappearance, and combined spatial and temporal expectation. The behavioral validity of the task was shown by the fact that all expectation conditions produced significantly shorter reaction times than the control state of no expectation. Spatial attention modulated early perceptual analysis in extrastriate areas, as demonstrated by significant enhancement of the visual P1 component. Temporal attention alone had no effect on P1 but instead modulated response-specific components. However, when spatial and temporal attention were combined, the enhancement of perceptual processing was significantly augmented, leading to a greater enhancement of the P1 component than by spatial attention alone. Perceptual analysis reflected by the P1 component correlated significantly with reaction times. In summary, event-related potentials revealed the presence of individual modulatory effects attributable to spatial and temporal expectation as well as synergistic effects indicative of an interaction of the two. This synergistic effect is likely to play a critical role in directing attention to the reappearance of a temporarily occluded moving target, a process of obvious importance in everyday situations.
This review paper is intended to be a guideline to novices on how to conduct research on silicate melt inclusions in volcanic environments, which analytical techniques are more suitable to gather the ...desired data and the major pitfalls scientist may encounter. Silicate melt inclusions (SMIs) are small quantities of silicate melt that are trapped in minerals during their growth or crystallization. They contain liquids formed in equilibrium with their host minerals and therefore record the liquid line of descent of magmatic systems. Upon trapping, SMIs become ideally closed to the surrounding environment, and behave as time capsules, giving important information about processes that originated magmas and the nature of their mantle source. A melt inclusions investigation is composed of several steps: (1) a detailed petrographic study to characterize and select representative SMIs, with the aim of identifying Melt Inclusions Assemblages (MIA), the only reliable tool to assess that SMIs obey Roedder's rules and have not re-equilibrated following entrapment; (2) a careful preparation of samples for re-heating experiments and microanalysis; (3) high temperature studies in order to homogenize the SMIs and be able to perform chemical analysis; (4) interpretation of SMIs data, which should always be compared with bulk rock composition and relevant experimentally derived liquid compositions. We suggest that the search for good SMI candidates for study will be achieved by good petrographic analysis of SMIs and detailed petrographic information (size, shape, appearance, position relative to the host and other SMI within the same host). If the goal of a SMIs study is to determine volatile concentrations, assessing the relative time of trapping among SMIs is of paramount importance, as it allows understanding if the variation in volatile concentrations is consistent with a certain magmatic physical–chemical process. Researchers that choose to work with SMIs face several challenges. SMIs are not always hosted in all samples or they can be difficult to recognize (mostly due to their small size). Additionally, due several processes, such as post-entrapment crystallization, boundary layer and sampling melt heterogeneity at the micron scale, they may not be representative of the original trapped melt composition.
•Silicate melt inclusions are small quantities of melt trapped in minerals during their growth.•Silicate melt inclusions record the liquid line of descent of magmatic systems.•The search for good SMI candidates for study is achieved by detailed petrographic study.•Their study includes homogenization and analysis by EMP, SIMS, Raman, FTIR, LA-ICPMS, etc.•Due to several processes, they may not be representative of the original trapped melt composition.
Aim: We sought to study the survival of newborn children according to HIV status of the mother, that of the child and the timing of infection.
Methods: This is a prospective cohort study of 883 ...mothers (665 HIV‐positive and 218 HIV‐negative) and their infants. Data were collected using semi‐structured questionnaires during home visits between the antenatal period and 36 weeks post‐delivery. Infant HIV status was determined at 3, 24 and 36 weeks by HIV DNA PCR.
Results: The majority (81.3%) of infected infants who died were infected by 3 weeks of age. Of the HIV‐exposed infants who died, 19 (28.4%) died before 6 weeks and 38 (56.7%) died by 12 weeks. The hazard ratio (HR) of mortality at 36 weeks of age in HIV‐infected infants compared with exposed but negative infants was 8.9 (95% CI: 6.7–11.8). There was no significant difference in 36 week survival rates between HIV‐non‐exposed and HIV‐exposed but negative infants (HR: 0.7; 95% CI: 0.3–1.5). The infant being HIV‐positive at age 3 weeks (HR: 32 95% CI: 14.0–73.1) and rural site (HR: 4.4 95% CI: 1.2–23.4) were the two independent risk factors for infant death amongst HIV‐exposed infants.
Conclusion: The prognosis for infants with early HIV infection was very poor in this cohort. A greater focus on prevention of early infection, earlier screening for HIV infection and access to antiretrovirals for eligible infants is recommended.
The antileukaemic tyrosine kinase inhibitor, imatinib, has been reported to inhibit specifically the growth of bcr-abl expressing CML progenitors at levels of 0.1-5.0 microM, by blocking the ...ATP-binding site of the kinase domain of bcr-abl. Inhibition of the c-abl, platelet-derived growth factor receptor and stem cell factor receptor (c-kit) tyrosine kinases by imatinib has also been reported. Here, we demonstrate that imatinib significantly inhibits in vitro monocyte/macrophage development from normal bone marrow progenitors, while neutrophil and eosinophil development was less affected. Monocyte/macrophage inhibition was observed in semisolid agar and liquid cultures at concentrations of imatinib as low as 0.3 microM. The maturation of monocytes into macrophages was also found to be impaired following treatment of cultures with 1.0 microM imatinib. Imatinib blocked monocyte/macrophage development in cultures stimulated with and without M-CSF, suggesting that inhibition of the M-CSF receptor, c-fms, by imatinib was unlikely to be responsible. Imatinib may therefore have an inhibitory activity for other kinase(s) that play a role in monocyte/macrophage differentiation. This inhibition of normal monocyte/macrophage development was observed at concentrations of imatinib achievable pharmacologically, suggesting that imatinib or closely related derivatives may have potential for the treatment of diseases where monocytes/macrophages contribute to pathogenesis.
Dystrophic or ectopic mineral deposition occurs in many pathologic conditions, including atherosclerosis. Calcium mineral deposits that frequently accompany atherosclerosis are readily quantifiable ...radiographically, serve as a surrogate marker for the disease, and predict a higher risk of myocardial infarction and death. Accelerating research interest has been propelled by a clear need to understand how plaque structure, composition, and stability lead to devastating cardiovascular events. In atherosclerotic plaque, accumulating evidence is consistent with the notion that calcification involves the participation of arterial osteoblasts and osteoclasts. Here we summarize current models of intimal arterial plaque calcification and highlight intriguing questions that require further investigation. Because atherosclerosis is a chronic vascular inflammation, we propose that arterial plaque calcification is best conceptualized as a convergence of bone biology with vascular inflammatory pathobiology.
BACKGROUND Abnormal bleeding is common in hormone therapy (HT) users. We aimed to determine how HT alters endometrial blood vessels and stromal factors known to regulate vascular growth and ...integrity. METHODS Prospective observational study of 165 post-menopausal women in Western Australia. The following were measured in endometrial biopsies: vascular density (vessels/mm2), total vessel area (total area enclosed by peripheral vascular immunostaining for perivascular pericytes in mm2), total luminal area (mm2) and vessel wall area (total vessel area minus luminal area), stromal expression of matrix metalloproteinases (MMP) -1, -3, -9 and -14, their tissue inhibitors (TIMPs) -1-4 and vascular endothelial growth factor (VEGF) by immunohistochemistry. RESULTS Total vessel area was greater during bleeding compared with HT users with no bleeding (P = 0.028) or with a prior irregular bleeding (P = 0.039). Total vessel area was greater in non-HT users compared with HT users with no bleeding (P = 0.021). In HT users, vessel luminal area was greater during bleeding compared with HT users with no bleeding (P = 0.030) and vessel wall area was also increased (P = 0.025). During bleeding there was an increase in stromal TIMP-2 staining (P = 0.044). No significant changes in endometrial MMP or VEGF were seen. CONCLUSIONS Abnormal bleeding in HT users is associated with changes in endometrial vessel size and in stromal expression of factors known to regulate vascular growth and integrity. These changes may contribute to abnormal bleeding.
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