Origin of cadmium enrichments in carbonate rocks deposited in the Alpine Tethys area during the Middle-Late Jurassic

ABSTRACTThe pollution of air, soil and water by heavy metals through anthropogenic activities is an object of numerous environmental studies since long times. A number of natural processes, such as volcanic activity, hydrothermal fluid circulation and weathering of metal-rich deposits may lead to an additional and potentially important input and accumulation of heavy metals in the environment. In the Swiss and French Jura Mountains, anomalous high cadmium (Cd) concentrations (up to 16 ppm) in certain soils are related to the presence of underlying Cd-enriched (up to 21 ppm) carbonate rocks of Middle to Late Jurassic age. The aim of this study is to understand the processes controlling Cd incorporation into carbonate rocks of Middle and Late Jurassic age and to reconstruct the sedimentary and environmental conditions, which have led to Cd enrichments in these sedimentary rocks.Cd concentrations in studied hemipelagic sections in France vary between 0.1 and 0.5 ppm (mean 0.15 ppm). Trace-element behavior and high Mn concentrations suggest that sediment accumulation occurred in a well-oxygenated environment. Increases in Cd contents in the bulk-rock carbonate sediments may be related to increases in surface-water productivity under oxic conditions and important remineralization of organic matter within the water column. In platform settings preserved in the Swiss Jura Mountains, no correlation is observed between Cd contents and evolution of environmental conditions. Cd concentrations in these platform sections are often below the detection limit, with isolated peaks of up to 21 ppm. These important Cd enrichments are associated with peaks in Zn concentrations and are present in carbonate rocks independently of facies and age. The high Cd contents in these shallow-water carbonate rocks are partly related to the presence of disseminated, Cd-rich (up to 1.8%), sphalerite (ZnS) mineralization. The basement rocks are considered to be the source of metals for sulfide mineralization in the overlying Jurassic strata, as the sphalerite Pb isotope pattern is comparable to that of granite rocks from the nearby southern Black Forest crystalline massif. The Rb-Sr ages of sphalerite samples indicate that a main phase of sphalerite formation occurred near the boundary between the late Middle and early Late Jurassic, at around 162 Ma, as a result of enhanced tectonic and hydrothermal activity in Europe, related to the opening of the Central Atlantic and to the tectonic/thermal subsidence during spreading of the Alpine Tethys. I therefore propose to use unusually high Cd concentrations in carbonates as a tracer of tectonic activity in the Jura Mountains area, especially in the case when important enrichments in Zn co-occur. Paleoproductivity reconstructions based on records of authigenic Cd may be compromised not only by post-depositional redistribution, but also by incorporation of additional Cd from hydrothermal solutions circulating in the rock.The circulation of metal-rich hydrothermal fluids through the sediment sequence, in addition to specific environmental conditions during sedimentation, contributes to the incorporation of Cd into the carbonate rocks. However, only hydrothermal activity has led to the unusually high concentrations of Cd in carbonate rocks of Bajocian-Oxfordian age, through the formation of sphalerite mineralization.

Facies, depositional environment, and palaeoecology of the Middle Triassic Cassina Beds (Meride Limestone, Monte San Giorgio, Switzerland).

The Ladinian Cassina beds belong to the fossiliferous levels of the world-famous Middle Triassic Monte San Giorgio Lagerstatte (UNESCO World Heritage List, Canton Ticino, Southern Alps). Although they are a rich archive for the depositional environment of an important thanatocoenosis, previous excavations focused on vertebrates and particularly on marine reptiles. In 2006, the Museo Cantonale di Storia Naturale (Lugano) started a new research project focusing for the first time on microfacies, micropalaeontological, palaeoecological and taphonomic analyses. So far, the upper third of the sequence has been excavated on a surface of around 40 m(2), and these new data complete those derived from new vertebrate finds (mainly fishes belonging to Saurichthys, Archaeosemionotus, Eosemionotus and Peltopleurus), allowing a better characterization of the basin. Background sedimentation on an anoxic to episodically suboxic seafloor resulted in a finely laminated succession of black shales and limestones, bearing a quasi-anaerobic biofacies, which is characterized by a monotypic benthic foraminiferal meiofauna and has been documented for the first time from the whole Monte San Giorgio sequence. Event deposition, testified by turbidites and volcaniclastic layers, is related to sediment input from basin margins and to distant volcanic eruptions, respectively. Fossil nekton points to an environment with only limited connection to the open sea. Terrestrial macroflora remains document the presence of emerged areas covered with vegetation and probably located relatively far away. Proliferation of benthic microbial mats is inferred on the basis of microfabrics, ecological considerations and taphonomic (both biostratinomic and diagenetic) features of the new vertebrate finds, whose excellent preservation is ascribed to sealing by biofilms. The occurrence of allochthonous elements allows an insight into the shallow-waters of the adjoining time-equivalent Salvatore platform. Finally, the available biostratigraphic data are critically reviewed.

Association between conventional risk factors and different ultrasound-based markers of atherosclerosis at carotid and femoral levels in a middle-aged population.

Ultrasound detection of sub-clinical atherosclerosis (ATS) may help identify individuals at high cardiovascular risk. Most studies evaluated intima-media thickness (IMT) at carotid level. We compared the relationships between main cardiovascular risk factors (CVRF) and five indicators of ATS (IMT, mean and maximal plaque thickness, mean and maximal plaque area) at both carotid and femoral levels. Ultrasound was performed on 496 participants aged 45-64 years randomly selected from the general population of the Republic of Seychelles. 73.4 % participants had ≥ 1 plaque (IMT thickening ≥ 1.2 mm) at carotid level and 67.5 % at femoral level. Variance (adjusted R2) contributed by age, sex and CVRF (smoking, LDL-cholesterol, HDL-cholesterol, blood pressure, diabetes) in predicting any of the ATS markers was larger at femoral than carotid level. At both carotid and femoral levels, the association between CVRF and ATS was stronger based on plaque-based markers than IMT. Our findings show that the associations between CVRF and ATS markers were stronger at femoral than carotid level, and with plaque-based markers rather than IMT. Pending comparison of these markers using harder cardiovascular endpoints, our findings suggest that markers based on plaque morphology assessed at femoral artery level might be useful cardiovascular risk predictors.

Prevalence of frailty indicators and association with socioeconomic status in middle-aged and older adults in a swiss region with universal health insurance coverage : a population-based cross-sectional study

Frailty prevalence in older adults has been reported but is largely unknown in middle-aged adults. We determined the prevalence of frailty indicators among middle-aged and older adults from a general Swiss population characterized by universal health insurance coverage and assessed the determinants of frailty with a special focus on socioeconomic status. Participants aged 50 and more from the population-based 2006-2010 Bus Santé study were included (N = 2,930). Four frailty indicators (weakness, shrinking, exhaustion, and low activity) were measured according to standard definitions. Multivariate logistic regressions were used to determine associations. Overall, 63.5%, 28.7%, and 7.8% participants presented no frailty indicators, one frailty indicator, and two or more frailty indicators, respectively. Among middle-aged participants (50-65 years), 75.1%, 22.2%, and 2.7% presented 0, 1, and 2 or more frailty indicators. The number of frailty indicators was positively associated with age, hypertension, and current smoking and negatively associated with male gender, body mass index, waist-to-hip ratio, and serum total cholesterol level. Lower income level but not education was associated with higher number of frailty indicators. Frailty indicators are frequently encountered in both older and middle-aged adults from the Swiss general population. Despite universal health insurance coverage, household income is independently associated with frailty.

Nutrition transition in a middle-income country: 22-year trends in the Seychelles.

BACKGROUND/OBJECTIVES: There is little objective information regarding nutrition transition in African countries. We assessed trends in nutrition patterns in the Seychelles between 1989 and 2011. SUBJECTS/METHODS: Population-based samples were obtained in 1989, 1994 and 2011 and participants aged 25-44 are considered in this study (n=493, 599 and 471, respectively). Similar, although not identical, food frequency questionnaires (FFQs) were used in each survey and the variables were collapsed into homogenous categories for the purpose of this study. RESULTS: Between 1989 and 2011, consumption frequency of fish (5+/week) decreased from 93 to 74%, whereas the following increased: meat (5+/week) 25 to 51%, fruits (1+/week) 48 to 94%, salty snacks (1+/week) 22 to 64% and sweet snacks (1+/week) 38 to 67% (P<0.001 for all). Consumption frequency decreased for home-brewed alcoholic drinks (1+/week) 16 to 1%, but increased for wine (1+/week) 5 to 33% (both P<0.001). Between 2004 and 2011, consumption frequency decreased for rice (2/day) 62 to 57% and tea (1+/day) 72 to 68%, increased for poultry (1+/week) 86 to 96% (all P<0.01), and did not change for vegetables (70.3 to 69.8%, P=0.65). CONCLUSIONS: Seychelles is experiencing nutrition transition characterized by a decreased consumption frequency of traditional staple foods (fish, polished rice), beverages (tea) and of inexpensive home brews, and increased consumption frequency of meat, poultry and snacks. Food patterns also became more varied along with a broader availability of products in the 22-year interval. The health impact of these changes should be further studied.

Evidence for multiple B- and T-cell epitopes in Plasmodium falciparum liver-stage antigen 3.

Liver-stage antigen 3 (LSA-3) is a new vaccine candidate that can induce protection against Plasmodium falciparum sporozoite challenge. Using a series of long synthetic peptides (LSP) encompassing most of the 210-kDa LSA-3 protein, a study of the antigenicity of this protein was carried out in 203 inhabitants from the villages of Dielmo (n = 143) and Ndiop (n = 60) in Senegal (the level of malaria transmission differs in these two villages). Lymphocyte responses to each individual LSA-3 peptide were recorded, some at high prevalences (up to 43%). Antibodies were also detected to each of the 20 peptides, many at high prevalence (up to 84% of responders), and were directed to both nonrepeat and repeat regions. Immune responses to LSA-3 were detectable even in individuals of less than 5 years of age and increased with age and hence exposure to malaria, although they were not directly related to the level of malaria transmission. Thus, several valuable T- and B-cell epitopes were characterized all along the LSA-3 protein, supporting the antigenicity of this P. falciparum vaccine candidate. Finally, antibodies specific for peptide LSP10 located in a nonrepeat region of LSA-3 were found significantly associated with a lower risk of malaria attack over 1 year of daily clinical follow-up in children between the ages of 7 and 15 years, but not in older individuals.

Suicidal expression among school-attending adolescents in a middle-income sub-Saharan country.

We investigated correlates for suicidal expression among adolescents in the Seychelles. Data on 1,432 students (52% females) were derived from the Global School-based Health Survey. Participants were divided into three groups: those with no suicidal behavior (N = 1,199); those with suicide ideation/SI (N = 89); and those reporting SI with a plan to carry out a suicide attempt/SISP (N = 139), each within a 12-month recall period. Using multinomial logistic regression, we examined the strength of associations with social, behavioral and economic indicators while adjusting for covariates. Sixteen percent of school-attending adolescents reported a suicidal expression (10% with a plan/6.2% without). Those reporting SI were younger (relative risk ratio RRR = 0.81; CI = 0.68-0.96), indicated signs of depression (RRR = 1.69; CI = 1.05-2.72) and loneliness (RRR=3.36; CI =1.93-5.84). Tobacco use (RRR = 2.34; CI = 1.32-4.12) and not having close friends (RRR = 3.32; CI = 1.54-7.15) were significantly associated with SI. Those with SISP were more likely to be female (RRR = 0.47; 0.30-0.74), anxious (RRR = 3.04; CI = 1.89-4.88) and lonely (RRR = 1.74; CI = 1.07-2.84). Having no close friends (RRR = 2.98; 1.56-5.69) and using tobacco (RRR = 2.41; 1.48-3.91) were also strongly associated. Having parents who were understanding was protective (RRR = 0.50; CI = 0.31-0.82). Our results suggest that school health promotion programs may benefit from targeting multiple factors associated with suicidal expression. More research, particularly multilevel designs are needed to identify peer and family influences which may modify associations with suicidality.

Subduction and obduction processes in the Swiss Alps

The significance of the Brianconnais domain in the Alpine orogen is reviewed in the light of data concerning its collision with the active Adriatic margin and the passive Helvetic margin. The Brianconnais which formerly belonged to the Iberian plate, was located on the northern margin of the Alpine Tethys (Liguro-Piemont ocean) since its opening in the early-Middle Jurassic. Together with the Iberian plate the Brianconnais terrane was separated from the European plate in the Late Jurassic-Early Cretaceous, following the northern Atlantic, Bay of Biscay, Valais ocean opening. This was accompanied by the onset of subduction along the northern margin of Adria and the closure of the Alpine Tethys. Stratigraphic and metamorphic data regarding this subduction and the geohistory of the Brianconnais allows the scenario of subduction-obduction processes during the Late Cretaceous-early Tertiary in the eastern and western Alps to be specified. HP-LT metamorphism record a long-lasting history of oceanic subduction-accretion, followed in the Middle Eocene by the incorporation of the Brianconnais as an exotic terrane into the accretionary prism. Middle to Late Eocene cooling ages of the Brianconnais basement and the presence of pelagic, anorogenic sedimentation lasting until the Middle Eocene on the Brianconnais preclude any sort of collision before that time between this domain and the active Adria margin or the Helvetic margin. This is confirmed by plate reconstructions constrained by magnetic anomalies in the Atlantic domain. Only a small percentage of the former Brianconnais domain was obducted, most of the crust and lithospheric roots were subducted. This applies also to domains formerly belonging to the southern Alpine Tethys margin (Austroalpine-inner Carpathian domain). It is proposed that there was a single Palaeogene subduction zone responsible for the Alpine orogen formation (from northern Spain to the East Carpathians), with the exception of a short-lived Late Cretaceous partial closure of the Valais ocean. Subduction in the western Tethyan domain originated during the closure of the Meliata ocean during the Jurassic incorporating the Austroalpine-Carpathian domain as terranes during the Cretaceous. The subduction zone propagated into the northern margin of Adria and then to the northern margin of the Iberian plate, where it gave birth to the Pyrenean-Provencal orogenic belt. This implies the absence of a separated Cretaceous subduction zone within the Austro-Carpathian Penninic ocean. Collision of Iberia with Europe forced the subduction to jump to the SE margin of Iberia in the Eocene, creating the Apenninic orogenic wedge and inverting the vergence of subduction from south- to north-directed. (C) 1998 Elsevier Science B.V. All rights reserved.

Sleep EEG changes after middle cerebral artery infarcts in mice: different effects of striatal and cortical lesions.

STUDY OBJECTIVES: Hemispheric stroke in humans is associated with sleep-wake disturbances and sleep electroencephalogram (EEG) changes. The correlation between these changes and stroke extent remains unclear. In the absence of experimental data, we assessed sleep EEG changes after focal cerebral ischemia of different extensions in mice. DESIGN: Following electrode implantation and baseline sleep-wake EEG recordings, mice were submitted to sham surgery (control group), 30 minutes of intraluminal middle cerebral artery (MCA) occlusion (striatal stroke), or distal MCA electrocoagulation (cortical stroke). One and 12 days after stroke, sleep-wake EEG recordings were repeated. The EEG recorded from the healthy hemisphere was analyzed visually and automatically (fast Fourier analysis) according to established criteria. MEASUREMENTS AND RESULTS: Striatal stroke induced an increase in non-rapid eye movement (NREM) sleep and a reduction of rapid eye movement sleep. These changes were detectable both during the light and the dark phase at day 1 and persisted until day 12 after stroke. Cortical stroke induced a less-marked increase in NREM sleep, which was present only at day 1 and during the dark phase. In cortical stroke, the increase in NREM sleep was associated in the wake EEG power spectra, with an increase in the theta and a reduction in the beta activity. CONCLUSION: Cortical and striatal stroke lead to different sleep-wake EEG changes in mice, which probably reflect variable effects on sleep-promoting and wakefulness-maintaining neuronal networks.

Denosumab for prevention of fractures in postmenopausal women with osteoporosis.

BACKGROUND: Denosumab is a fully human monoclonal antibody to the receptor activator of nuclear factor-kappaB ligand (RANKL) that blocks its binding to RANK, inhibiting the development and activity of osteoclasts, decreasing bone resorption, and increasing bone density. Given its unique actions, denosumab may be useful in the treatment of osteoporosis. METHODS: We enrolled 7868 women between the ages of 60 and 90 years who had a bone mineral density T score of less than -2.5 but not less than -4.0 at the lumbar spine or total hip. Subjects were randomly assigned to receive either 60 mg of denosumab or placebo subcutaneously every 6 months for 36 months. The primary end point was new vertebral fracture. Secondary end points included nonvertebral and hip fractures. RESULTS: As compared with placebo, denosumab reduced the risk of new radiographic vertebral fracture, with a cumulative incidence of 2.3% in the denosumab group, versus 7.2% in the placebo group (risk ratio, 0.32; 95% confidence interval [CI], 0.26 to 0.41; P<0.001)--a relative decrease of 68%. Denosumab reduced the risk of hip fracture, with a cumulative incidence of 0.7% in the denosumab group, versus 1.2% in the placebo group (hazard ratio, 0.60; 95% CI, 0.37 to 0.97; P=0.04)--a relative decrease of 40%. Denosumab also reduced the risk of nonvertebral fracture, with a cumulative incidence of 6.5% in the denosumab group, versus 8.0% in the placebo group (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01)--a relative decrease of 20%. There was no increase in the risk of cancer, infection, cardiovascular disease, delayed fracture healing, or hypocalcemia, and there were no cases of osteonecrosis of the jaw and no adverse reactions to the injection of denosumab. CONCLUSIONS: Denosumab given subcutaneously twice yearly for 36 months was associated with a reduction in the risk of vertebral, nonvertebral, and hip fractures in women with osteoporosis. (ClinicalTrials.gov number, NCT00089791.)

Subjective Memory Deficits in People with and without Dementia: Findings from the 10/66 Dementia Research Group Pilot Studies in Low- and Middle-Income Countries

OBJECTIVES To compare subjective memory deficit (SMD) in older adults with and without dementia or depression across multiple centers in low- and middle-income countries (LAMICs). DESIGN Secondary analysis of data from 23 case control studies. SETTING Twenty-three centers in India, Southeast Asia (including China), Latin America and the Caribbean, Nigeria, and Russia. PARTICIPANTS Two thousand six hundred ninety-two community-dwelling people aged 60 and older in one of three groups: people with dementia, people with depression, and controls free of dementia and depression. MEASUREMENTS SMD was derived from the Geriatric Mental State examination. RESULTS Median SMD frequency was lowest in participants without dementia (26.2%) and higher in those with depression (50.0%) and dementia (66.7%). Frequency of SMD varied between centers. Depression and dementia were consistently associated with SMD. Older age and hypochondriasis were associated with SMD only in subjects without dementia. In those with dementia, SMD was associated with better cognitive function, whereas the reverse was the case in controls. CONCLUSION Associations with SMD may differ between subjects with and without dementia living in LAMICs.

Hemispheric processing of differently valenced and self-relevant attachment words in middle-aged married and separated individuals

The reliance in experimental psychology on testing undergraduate populations with relatively little life experience, and/or ambiguously valenced stimuli with varying degrees of self-relevance, may have contributed to inconsistent findings in the literature on the valence hypothesis. To control for these potential limitations, the current study assessed lateralised lexical decisions for positive and negative attachment words in 40 middle-aged male and female participants. Self-relevance was manipulated in two ways: by testing currently married compared with previously married individuals and by assessing self-relevance ratings individually for each word. Results replicated a left hemisphere advantage for lexical decisions and a processing advantage of emotional over neutral words but did not support the valence hypothesis. Positive attachment words yielded a processing advantage over neutral words in the right hemisphere, while emotional words (irrespective of valence) yielded a processing advantage over neutral words in the left hemisphere. Both self-relevance manipulations were unrelated to lateralised performance. The role of participant sex and age in emotion processing are discussed as potential modulators of the present findings.