Prélèvement à la source de l’impôt sur le revenu : comment faire ?

Le gouvernement a décidé de reporter le prélèvement à la source de l’impôt sur le revenu (IR) à janvier 2019. A partir de cette date, les employeurs prélèveront directement l’impôt sur la fiche de paie à un taux transmis par l’administration fiscale. Ce taux sera calculé sur la base de la déclaration fiscale effectuée au printemps 2018 (sur les revenus 2017). En 2019, l’impôt sera ainsi payé sur les revenus 2019. L’avantage principal de la réforme réside dans cette contemporanéité : si les revenus d’un ménage baissent (chômage, départ à la retraite, …), l’impôt baissera proportionnellement[1]. En cas de changement de situation conduisant à une baisse prévisible significative de l’impôt dû, les ménages pourront demander en cours d’année sur le site impots.gouv.fr une mise à jour de leur taux de prélèvement à la source, de sorte que la baisse de l’impôt payé sera plus que proportionnelle. Le prélèvement à la source évite ainsi les difficultés de trésorerie pour les personnes dont la situation change en cours d’année. Du point de vue de l’Etat, le prélèvement à la source permettrait également une plus grande efficacité des stabilisateurs automatiques (l’IR variera en temps réel avec les revenus). [Premier paragraphe

IMB 1800 Programs for Data processing at the Accelerators of the Central Bureau for Nuclear Measurements. Part 3: Programs for Interactive Data Reduction. EUR 4404.

<p>A, miR393 and <i>DlCHS</i>; B, miR393 and <i>DlCHI</i>; C, miR393 and <i>DlFLS</i>; D, miR393 and <i>DlF3′H</i>; E, miR393 and <i>DlDFR</i>; F, miR393 and <i>DlLAR</i>; G, miR393 and its target gene <i>DlTIR1-3</i>.</p

Flexible CNT-MXene-CNT Film with Low Surface Conductance for High- and Low-Power Electromagnetic Absorption Protection

High absorption performance terahertz (THz) and GHz absorbers with low surface conductance are urgently indispensable in the application of military electromagnetic protection and multiband communication. Herein, cost-effective approaches of modified grafting and hot-pressing molding methods are proposed to construct CNT-MXene-CNT films based on a modified methyl vinyl silicone rubber (MVSR). The resultant 3 mm CNT-1.1-MXene-1.9-CNT-1.1 sample exhibits average electromagnetic interference shielding effectiveness (EMI SE) of about 29.2 dB in the range of 2–12.5 GHz and favorable EMI SE of 48.2 dB within 0.1–2.2 THz. In addition, the optimized sample also obtains excellent EMI SE of about 31.8 and 41.2 dB under the high-power test conditions in the GHz and THz bands. Besides, the CNT-1.1-MXene-1.9-CNT-1.1 sample possesses only about 1.5% overall loading content with a low surface conductivity of 2.3 μS/m. The as-prepared absorber with a low surface conductance demonstrates enormous potential in future military and civilian applications

Total Synthesis of (−)-Spinosyn A via Carbonylative Macrolactonization

Spinosyn A (<b>1</b>), a complex natural product featuring a unique 5,6,5,12-fused tetracyclic core structure, is the major component of spinosad, an organic insecticide and an FDA-approved agent used worldwide. Herein, we report an efficient total synthesis of (−)-spinosyn A with 15 steps in the longest linear sequence and 23 steps total from readily available compounds <b>14</b> and <b>23</b>. The synthetic approach features several important catalytic transformations including a chiral amine-catalyzed intramolecular Diels–Alder reaction to afford <b>22</b> in excellent diastereoselectivity, a one-step gold-catalyzed propargylic acetate rearrangement to convert <b>28</b> to α-iodoenone <b>31</b>, an unprecedented palladium-catalyzed carbonylative Heck macrolactonization to form the 5,12-fused macrolactone in one step, and a gold-catalyzed Yu glycosylation to install the challenging β-forosamine. This total synthesis is highly convergent and modular, thus offering opportunities to synthesize spinosyn analogues in order to address the emerging cross-resistance problems

Biosynthetically Inspired Divergent Approach to Monoterpene Indole Alkaloids: Total Synthesis of Mersicarpine, Leuconodines B and D, Leuconoxine, Melodinine E, Leuconolam, and Rhazinilam

Inspired by their potential biosynthesis, we have developed divergent total syntheses of seven monoterpene indole alkaloids including mersicarpine, leuconodines B and D, leuconoxine, melodinine E, leuconolam, and rhazinilam, and one unnatural analogue with an unprecedented structural skeleton. The key steps involve a Witkop–Winterfeldt oxidative indole cleavage followed by transannular cyclization. The transannular cyclization product was then converted to the corresponding structural skeletons by pairing its functional groups into different reaction modes

Percentage of cuticular hydrocarbons of <i>Acyrthosiphon pisum</i> translocated from <i>Trifolium repens</i> to <i>Vicia faba</i>.

<p>Percentage of cuticular hydrocarbons of <i>Acyrthosiphon pisum</i> translocated from <i>Trifolium repens</i> to <i>Vicia faba</i>.</p

Principal components analysis (PCA) of CHC profiles of the 3rd instar nymphs, wingless and winged adults of <i>A</i>. <i>pisum</i>.

<p>The GNY morph was used for direct SPME sampling with 7 μm PDMS fiber. Shown are score plots of PC 1 versus 2, with the percentage of total variance explained by each axis given in parentheses. Each symbol represents an aphid individual. Data points for each group are enclosed within a line.</p

Percentage of cuticular hydrocarbons at different developmental stages of <i>Acyrthosiphon pisum</i>.

<p>Percentage of cuticular hydrocarbons at different developmental stages of <i>Acyrthosiphon pisum</i>.</p

Coefficient of variation (%) of the measurements for each of the nine CHC components.

<p>Coefficient of variation (%) of the measurements for each of the nine CHC components.</p

Principal components analysis (PCA) of CHC profiles of five geographic morphs of <i>A</i>. <i>pisum</i>.

<p>Wingless adults of each morph reared on <i>V</i>. <i>faba</i> were used for SPME sampling (7 μm PDMS). Shown are score plots of PC 1 versus 2, with the percentage of total variance explained by each axis denoted in parentheses. Each symbol represents an aphid individual. Data points for each morph are enclosed within a line. Factor loadings of CHC components on each PC are indicated in panel (B).</p