233: Symmetric dimethylarginine serum level as a new marker of left ventricular ejection fraction in patients with acute myocardial infarction

Asymmetric dimethylarginine (ADMA) is a by-product of protein methylation implicated in the prognosis after acute myocardial infarction (MI) and heart failure through Nitric Oxide Synthase (NOS) inhibition. We aimed to investigate whether SDMA - the endogenous symmetrical stereoisomer of ADMA - that has insignificant inhibitory effects on NOS might be a marker of left ventricular function in acute MI.MethodsBlood samples from 468 consecutive patients hospitalized <24 hours after acute MI were taken on admission. Serum levels of ADMA and SDMA were determined using high-performance liquid chromatography. Left ventricular ejection fraction (LVEF) was assessed by echocardiography at 2±1 d after admission.ResultsAmong the study population, mean age was 66±14 y, most were male (77%), hypertensive (54%), with prior CAD (20%) or diabetes (20%). On admission, half had ST segment elevation MI (STEMI) (55%), and ¼ suffered from heart failure, as assessed by killip>1 (23%). Mean LVEF was 52±13%. Mean ADMA and SDMA levels were at 0.81±0.42 and 0.61±0.44, respectively. Spearman analysis showed that LVEF was correlated negatively with SDMA (r=-0.135, p=0.006), but neither with ADMA (r=-0.001, p=0.99). SDMA was strongly associated with age (r=+0.354, p<0.001), creatinine clearance (r=-0.416, p<0.001), CRP (r=+0.134, p=0.004) and homocysteine (r=+0.413, p<0.001). By univariate linear regression analysis, age, homocysteine, hypertension, diabetes, prior CAD, admission heart rate, creatinine clearance, anterior wall location, STEMI, CK peak, and acute statin treatment, in addition to SDMA, were significantly associated with LVEF (p<0.05). Backward multivariate analysis including these covariates showed that SDMA remains an independent predictor of LVEF (B=-3.422; SE=1.687, p=0.043), beyond classical determinants of LVEF including age, homocysteine and renal function.ConclusionOur large prospective study showed for the first time that SDMA, but ADMA, may be linked to left ventricular function in patients with acute MI, and suggests that such dimethylarginines may probably exert biological activity by other pathways than NOS activity inhibition and beyond renal function

Rock magnetic investigation of possible sources of the Bangui magnetic anomaly

International audienceThe Bangui magnetic anomaly (BMA) is the largest lithospheric magnetic field anomaly on Earth at low latitudes. Previous studies investigated its geological source using constraints from satellite and ground magnetic field measurements, as well as from surface magnetic susceptibility measurements on rocks from the Panafrican Mobile Belt Zone (PMBZ). Here we combine magnetic field data modelling and rock magnetic property measurements (susceptibility and natural remanent magnetization, NRM) on many samples from this PMBZ and the surrounding formations. It reveals that NRM is a significant component of the total magnetization (Mt) of the BMA source, which reaches 4.3 A/m with maximum thicknesses of 38 and 54 km beneath the western and eastern parts of the BMA. Only the isolated and relatively thin banded iron formations and some migmatites show such Mt values. Thus we suggest that the thick BMA source may be composed either by overlapped slices of such metamorphic rocks, or by an iron-rich mafic source, or by a combination of these two geological structures

Magnetic field microscopy of rock samples using a giant magnetoresistance–based scanning magnetometer

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95412/1/ggge1634.pd

La gestion des biosolides de papetières au Québec : quelle serait la meilleure option pour réduire les émissions de gaz à effet de serre? (Pulp and paper mill sludge management in Quebec: what should be the best option to reduce greenhouse gas emissions?)

Les biosolides de papetières (BP) sont des matières organiques résiduelles provenant du processus d’épuration des effluents de l’industrie des pâtes et papiers. Le gouvernement québécois vise à réduire de 20 % les émissions de gaz à effet de serre (GES) par rapport au niveau de 1990 et à bannir la matière organique des lieux d’élimination d’ici 2020, ce qui affectera probablement la gestion des BP. Cette étude vise à quantifier les émissions de GES provenant des trois principales filières de gestion des BP : l’enfouissement, l’épandage sur sol agricole et la combustion avec récupération de chaleur. Les émissions de GES de l’enfouissement ont été mesurées à l’échelle pilote et celles de l’épandage, l’ont été pour des doses respectant les recommandations agronomiques. Les émissions de la combustion ont été mesurées à la cheminée de chaudières à biomasse utilisant entre 10 et 40 % de BP mélangés aux combustibles. L’enfouissement était la filière la plus émettrice de GES (0,90 t éq. CO2 t-1 BP secs), alors que les émissions étaient inférieures pour l’épandage (0,12 t éq. CO2 t-1 BP secs) et la combustion (0,00057-0,13 t éq. CO2 t-1 BP secs). L’épandage agricole et la combustion seraient de bonnes alternatives à l’enfouissement pour atténuer les émissions de GES. Toutefois, il serait nécessaire de multiplier les mesures d’émissions pour en augmenter la précision et assurer des scénarios robustes si l’on vise à initier l’élaboration d’un nouveau protocole d’obtention de crédits compensatoires pour le système de plafonnement et d’échange de droits d’émission de GES au Québec. Pulp and paper mill sludge (PPMS) is an organic residual generated from the paper mill wastewater treatments. The Quebec’s government policies aim to reduce the greenhouse gas emissions (GHG) by 20% below the level of 1990 and to ban disposal (landfilling and incineration without energy recovery) of organic material by 2020, which will likely affect PPMS management. This study aims at quantifying GHG emissions from the three main practices currently used to manage PPMS: landfilling, land application in agriculture and combustion for energy recovery. GHG emissions from landfilling were measured at the pilot-scale and those from land were measured following PPMS application at rates based on local agronomic recommendations. GHG emissions from combustion were measured at the chimney of biomass boilers using 10 to 40% PPMS in the fuel. Landfilling had the highest GHG emissions (0.90 t CO2e t-1 dry PPMS) whereas those from land application (0.12 t CO2e t-1 dry PPMS) and combustion (0.00057-0.13 t CO2e t-1 dry PPMS) were lower. Application of PPMS to agricultural land and combustion would therefore be good alternatives to landfilling to abate GHG emissions. However, more measurements would be required to increase the accuracy on the emission quantifications and start building a new offset credit protocol to be used in the Quebec cap-and-trade system for GHG emission allowances applied bylaw

Villæ – Villages du haut Moyen Âge en plaine du Languedoc oriental. Maillage, morphologie et économie

Le village de plaine en Languedoc oriental au premier Moyen Âge était encore, ces dernières années, un grand inconnu. Non qu’il fut rare entre les ve et xiie siècles – c’est au contraire manifestement la forme d’habitat la plus répandue à partir du ixe siècle –, mais parce qu’il n’a laissé que peu de traces, tant dans la documentation écrite et iconographique qu’au sol. Peu d’historiens se sont attachés au sujet, ce que la parcimonie des sources explique en grande partie. Les archéologues, de..

Comparative Gene Expression Analysis throughout the Life Cycle of Leishmania braziliensis: Diversity of Expression Profiles among Clinical Isolates

Leishmania is a group of parasites (Protozoa, Trypanosomatidae) responsible for a wide spectrum of clinical forms. Among the factors explaining this phenotypic polymorphism, parasite features are important contributors. One approach to identify them consists in characterizing the gene expression profiles throughout the life cycle. In a recent study, the transcriptome of 3 Leishmania species was compared and this revealed species-specific differences, albeit in a low number. A key issue, however, is to ensure that the observed differences are indeed species-specific and not specific of the strains selected for representing the species. In order to illustrate the relevance of this concern, we analyzed here the gene expression profiles of 5 clinical isolates of L. braziliensis at seven time points of the life cycle. Our results clearly illustrate the unique character of each isolate in terms of gene expression dynamics: one Leishmania strain is not necessarily representative of a given species

Greenhouse gas emissions after application of landfilled paper mill sludge for land reclamation of a nonacidic mine tailings site

Large areas of mine tailings are reclaimed by applying organic amendments such as paper mill sludge (PMS). Although mining industries can use PMS freshly generated by paper mills, operational constraints on paper industries make temporary landfilling of this material an unavoidable alternative for the paper industries, creating the most prominent PMS source for mining industries. This study aimed to quantify soil greenhouse gas (GHG) emissions (N2O, CO2, and CH4) after application of landfilled PMS (LPMS; i.e., excavated from a landfill site at a paper mill) and LPMS combined with a seeding treatment of white clover (Trifolium repens L.) on nonacidic mine tailings site prior to reforestation. Soil N2O, CO2, and CH4 fluxes were measured after applications of 50 and 100 Mg dry LPMS ha−1 during two consecutive snowfree seasons on two adjacent sites; LPMS was applied once in the first season. The LPMS application increased N2O emissions (7.6 to 34.7 kg N2O-N ha−1, comprising 1.04 to 2.43% of applied N) compared with the unamended control during the first season; these emissions were negligible during the second season. The LPMS application increased CO2 emissions (~5800 to 11,400 kg CO2–C ha−1, comprising 7 to 27% of applied C) compared with the unamended control on both sites and in both seasons. Fluxes of CH4 were negligible. White clover combined with LPMS treatments did not affect soil GHG emissions. These new GHG emission factors should be integrated into life-cycle analyses to evaluate the C footprint of potential symbioses between the mining and paper industries. Future research should focus on the effect of PMS applications on soil GHG emissions from a variety of mine tailings under various management practices and climatic conditions to plan responsible and sustainable land reclamation

Importance of proximity to resources, social support, transportation and neighborhood security for mobility and social participation in older adults: results from a scoping study

ABSTRACT: Background: Since mobility and social participation are key determinants of health and quality of life, it is important to identify factors associated with them. Although several investigations have been conducted on the neighborhood environment, mobility and social participation, there is no clear integration of the results. This study aimed to provide a comprehensive understanding regarding how the neighborhood environment is associated with mobility and social participation in older adults.Methods: A rigorous methodological scoping study framework was used to search nine databases from different fields with fifty-one keywords. Data were exhaustively analyzed, organized and synthesized according to the International Classification of Functioning, Disability and Health (ICF) by two research assistants following PRISMA guidelines, and results were validated with knowledge users.Results: The majority of the 50 selected articles report results of cross-sectional studies (29; 58 %), mainly conducted in the US (24; 48 %) or Canada (15; 30 %). Studies mostly focused on neighborhood environment associations with mobility (39; 78 %), social participation (19; 38 %), and occasionally both (11; 22 %). Neighborhood attributes considered were mainly 'Pro ducts and technology' (43; 86) and 'Services, systems and policies' (37; 74 %), but also 'Natural and human- made changes' (27; 54 %) and 'Support and relationships' (21; 42 %). Mobility and social participation were both positively associated with Proximity to resources and recreational facilities, Social support, Having a car or driver's license, Public transportation and Neighborhood security, and negatively associated with Poor user-friendliness of the walking environment and Neighborhood insecurity. Attributes of the neighborhood environment not covered by previous research on mobility and social participation mainly concerned 'Attitudes', and 'Services, systems and policies'.Conclusion: Results from this comprehensive synthesis of empirical studies on associations of the neighborhood environment with mobility and social participation will ultimately support best practices, decisions and the development of innovative inclusive public health interventions including clear guidelines for the creation of age-supportive environments. To foster mobility and social participation, these interventions must consider Proximity to resources and to recreational facilities, Social support, Transportation, Neighborhood security and User-friendliness of the walking environment. Future studies should include both mobility and social participation, and investigate how they are associated with 'Attitudes', and 'Services, systems and policies' in older adults, including disadvantaged older adults