Contrôle des pesticides organochlorés dans le lait et produits laitiers : Bioaccumulation et risques d’exposition

La présente étude vise à déterminer les teneurs des pesticides organochlorés (POC) dans le lait de vache et du beurre élaboré traditionnellement. Ainsi, 90 échantillons de lait et 45 échantillons de beurre ont été collectés auprès des éleveurs installés dans les régionsde Buyo, Grand-lahou et Yamoussoukro. Ces échantillons ont été traités en vue de déterminer les résidus de 14 POC. Les analyses ont été menées par chromatographie en phase gazeuse sur colonne capillaire avec un détecteur à capture d'électrons (ECD). Les résultats observés révèlent une contamination générale du lait et du beurre par les POC.Ainsi, des charges moyennes en hexachlorocyclohexane (HCH) de 42,75 mg/kg et 165,94 mg/kg), en endosulfane de 31,58 et 436,80 mg/kg, en heptachlore 8,70 et 59,91 mg/kg et en Dichlorodiphenyltrichloroethane (DDT) 36,20 et 227,82 mg/kg, ont été respectivement déterminées dans le lait et dans le beurre. La teneur résiduelle moyenne des isomères HCH et des cyclodiènes (dieldrine, endosulfane et heptachlore) constitue respectivement 36,9 % et 13,2 % de la moyenne du total des POC mesurés dans le lait et respectivement 40,7 % et 28,2 % de celle mesurée dans le beurre. Le DDT et ses métabolites mesurés dans nos échantillons représentent 49,9 % du total des POC du lait et 31 % pour le beurre.Mots-clés : Pesticides organochlorés, lait de vache, bioaccumulation, écotoxicologie, lacs, Côte d’Ivoir

Black Hole Entropy without Brick Walls

We present evidence which confirms a suggestion by Susskind and Uglum regarding black hole entropy. Using a Pauli-Villars regulator, we find that 't Hooft's approach to evaluating black hole entropy through a statistical-mechanical counting of states for a scalar field propagating outside the event horizon yields precisely the one-loop renormalization of the standard Bekenstein-Hawking formula, S=\A/(4G). Our calculation also yields a constant contribution to the black hole entropy, a contribution associated with the one-loop renormalization of higher curvature terms in the gravitational action.Comment: 15 pages, plain LaTex minor additions including some references; version accepted for publicatio

Modeled Health and Economic Impact of Team-Based Care for Hypertension

IntroductionTeam-based interventions for hypertension care have been widely studied and shown effective in improving hypertension outcomes. Few studies have evaluated long-term effects of these interventions; none have assessed broad-scale implementation. This study estimates the prospective health, economic, and budgetary impact of universal adoption of a team-based care intervention model that targets people with treated but uncontrolled hypertension in the U.S.MethodsAnalysis was conducted in 2014−2015 using a microsimulation model, constructed with various data sources from 1948 to 2014, designed to evaluate prospective cardiovascular disease (CVD)−related interventions in the U.S. population. Ten-year primary outcomes included prevalence of uncontrolled hypertension; incident myocardial infarction, stroke, CVD events, and CVD-related mortality; intervention and net medical costs by payer; productivity; and quality-adjusted life years.ResultsAbout 4.7 million (13%) fewer people with uncontrolled hypertension and 638,000 prevented cardiovascular events would be expected over 10 years. Assuming $525 per enrollee, implementation would cost payers$22.9 billion, but $25.3 billion would be saved in averted medical costs. Estimated net cost savings for Medicare approached$5.8 billion. Net costs were especially sensitive to intervention costs, with break-even thresholds of $300 (private),$450 (Medicaid), and $750 (Medicare).ConclusionsNationwide adoption of team-based care for uncontrolled hypertension could have sizable effects in reducing CVD burden. Based on the study’s assumptions, the policy would be cost saving from the perspective of Medicare and may prove to be cost effective from other payers’ perspectives. Expected net cost savings for Medicare would more than offset expected net costs for all other insurers

Iodofiltic Acid I 123 (BMIPP) Fatty Acid Imaging Improves Initial Diagnosis in Emergency Department Patients With Suspected Acute Coronary Syndromes A Multicenter Trial

ObjectivesThe aim of this study was to assess the performance of β-methyl-p-[123I]-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) to detect acute coronary syndromes (ACS) in emergency department patients with chest pain.BackgroundEmergency department diagnosis of chest pain is problematic, often requiring prolonged observation and stress testing. BMIPP SPECT detects abnormalities in fatty acid metabolism resulting from myocardial ischemia, even many hours after symptom cessation.MethodsEmergency department patients with suspected ACS were enrolled at 50 centers. Patients received 5 mCi BMIPP within 30 h of symptom cessation. BMIPP SPECT images were interpreted semiquantitatively by 3 blinded readers. Initial clinical diagnosis was based on symptoms, initial electrocardiograms, and troponin, whereas the final diagnosis was based on all available data (including angiography and stress SPECT) but not BMIPP SPECT. Final diagnoses were adjudicated by a blinded committee as ACS, intermediate likelihood of ACS, or negative for ACS.ResultsA total of 507 patients were studied and efficacy was evaluated in 448 patients with sufficient data. The sensitivity of BMIPP by 3 blinded readers for a final diagnosis of ACS and intermediate likelihood of ACS was 71% (95% confidence interval [CI]: 64% to 79%), 74% (95% CI: 68% to 81%), and 69% (95% CI: 62% to 77%); the corresponding specificity of BMIPP was 67% (95% CI: 61% to 73%), 54% (95% CI: 48% to 60%), and 70% (95% CI: 64% to 76%). Compared with the initial diagnosis alone, BMIPP + initial diagnosis increased sensitivity from 43% to 81% (p < 0.001), negative predictive value from 62% to 83% (p < 0.001), and positive predictive value from 41% to 58% (p < 0.001), whereas specificity was unchanged (61% to 62%, p = NS).ConclusionsThe addition of BMIPP data to the initially available clinical information adds incremental value toward the early diagnosis of an ACS, potentially allowing determination of the presence or absence of ACS to be made earlier in the evaluation process. (Safety and Efficacy Iodofiltic Acid I 123 in the Treatment of Acute Coronary Syndrome [Zeus-ACS]; NCT00514501

The MRN complex is transcriptionally regulated by MYCN during neural cell proliferation to control replication stress

The MRE11/RAD50/NBS1 (MRN) complex is a major sensor of DNA double strand breaks, whose role in controlling faithful DNA replication and preventing replication stress is also emerging. Inactivation of the MRN complex invariably leads to developmental and/or degenerative neuronal defects, the pathogenesis of which still remains poorly understood. In particular, NBS1 gene mutations are associated with microcephaly and strongly impaired cerebellar development, both in humans and in the mouse model. These phenotypes strikingly overlap those induced by inactivation of MYCN, an essential promoter of the expansion of neuronal stem and progenitor cells, suggesting that MYCN and the MRN complex might be connected on a unique pathway essential for the safe expansion of neuronal cells. Here, we show that MYCN transcriptionally controls the expression of each component of the MRN complex. By genetic and pharmacological inhibition of the MRN complex in a MYCN overexpression model and in the more physiological context of the Hedgehog-dependent expansion of primary cerebellar granule progenitor cells, we also show that the MRN complex is required for MYCN-dependent proliferation. Indeed, its inhibition resulted in DNA damage, activation of a DNA damage response, and cell death in a MYCN- and replication-dependent manner. Our data indicate the MRN complex is essential to restrain MYCN-induced replication stress during neural cell proliferation and support the hypothesis that replication-born DNA damage is responsible for the neuronal defects associated with MRN dysfunctions.Cell Death and Differentiation advance online publication, 12 June 2015; doi:10.1038/cdd.2015.81

Born-Infeld Theory and Stringy Causality

Fluctuations around a non-trivial solution of Born-Infeld theory have a limiting speed given not by the Einstein metric but the Boillat metric. The Boillat metric is S-duality invariant and conformal to the open string metric. It also governs the propagation of scalars and spinors in Born-Infeld theory. We discuss the potential clash between causality determined by the closed string and open string light cones and find that the latter never lie outside the former. Both cones touch along the principal null directions of the background Born-Infeld field. We consider black hole solutions in situations in which the distinction between bulk and brane is not sharp such as space filling branes and find that the location of the event horizon and the thermodynamic properties do not depend on whether one uses the closed or open string metric. Analogous statements hold in the more general context of non-linear electrodynamics or effective quantum-corrected metrics. We show how Born-Infeld action to second order might be obtained from higher-curvature gravity in Kaluza-Klein theory. Finally we point out some intriguing analogies with Einstein-Schr\"odinger theory.Comment: 31 pages, 4 figures, LaTex; Some comments and references adde

Heterogeneity in the longitudinal courses of global functioning in children at familial risk of major psychiatric disorders: Association with trauma and familial characteristics

Abstract Objectives The extent to which heterogeneity in childhood risk trajectories may underlie later heterogeneity in schizophrenia (SZ), bipolar disorder (BP), and major depressive disorder (MDD) remains a chief question. Answers may optimally be found by studying the longitudinal trajectories of children born to an affected parent. We aimed to differentiate trajectories of global functioning and their sensitive periods from the age of 6 to 17 years in children at familial risk (FHRs). Methods First, a latent class mixed model analysis (LCMM) was applied to yearly ratings of the Children's Global Assessment Scale (CGAS) from the age of 6 to 17 years in 170 FHRs born to a parent affected by DSM-IV SZ (N = 37), BP (N = 82) or MDD (N = 51). Then, we compared the obtained Classes or trajectories of FHRs in terms of sex, parental diagnosis, IQ, child clinical status, childhood trauma, polygenic risk score (PRS), and outcome in transition to illness. Results The LCMM on yearly CGAS trajectories identified a 4-class solution showing markedly different childhood and adolescence dynamic courses and temporal vulnerability windows marked by a functioning decline and a degree of specificity in parental diagnosis. Moreover, IQ, trauma exposure, PRS level, and timing of later transition to illness differentiated the trajectories. Almost half (46%) of the FHRs exhibited a good and stable global functioning trajectory. Conclusions FHRs of major psychiatric disorders show heterogeneous functional decline during development associated with parental diagnosis, polygenic risk loading, and childhood trauma

The nucleon-nucleon interaction

We review the major progress of the past decade concerning our understanding of the nucleon-nucleon interaction. The focus is on the low-energy region (below pion production threshold), but a brief outlook towards higher energies is also given. The items discussed include charge-dependence, the precise value of the $\pi NN$ coupling constant, phase shift analysis and high-precision NN data and potentials. We also address the issue of a proper theory of nuclear forces. Finally, we summarize the essential open questions that future research should be devoted to.Comment: 42 pages, 12 figures, iopart.cls style; Topical Review prepared for J. Phys. G: Nucl. Part. Phy