Post-Newtonian factorized multipolar waveforms for spinning, non-precessing black-hole binaries

We generalize the factorized resummation of multipolar waveforms introduced by Damour, Iyer and Nagar to spinning black holes. For a nonspinning test-particle spiraling a Kerr black hole in the equatorial plane, we find that factorized multipolar amplitudes which replace the residual relativistic amplitude f_{l m} with its l-th root, \rho_{l m} = f_{l m}^{1/l}, agree quite well with the numerical amplitudes up to the Kerr-spin value q \leq 0.95 for orbital velocities v \leq 0.4. The numerical amplitudes are computed solving the Teukolsky equation with a spectral code. The agreement for prograde orbits and large spin values of the Kerr black hole can be further improved at high velocities by properly factoring out the lower-order post-Newtonian contributions in \rho_{l m}. The resummation procedure results in a better and systematic agreement between numerical and analytical amplitudes (and energy fluxes) than standard Taylor-expanded post-Newtonian approximants. This is particularly true for higher-order modes, such as (2,1), (3,3), (3,2), and (4,4) for which less spin post-Newtonian terms are known. We also extend the factorized resummation of multipolar amplitudes to generic mass-ratio, non-precessing, spinning black holes. Lastly, in our study we employ new, recently computed, higher-order post-Newtonian terms in several subdominant modes, and compute explicit expressions for the half and one-and-half post-Newtonian contributions to the odd-parity (current) and even-parity (odd) multipoles, respectively. Those results can be used to build more accurate templates for ground-based and space-based gravitational-wave detectors.Comment: 37 pages, 11 figures; Typos in Sec.IV Eqs.(38-42) fixe

Caractérisation de variables de structure forestière à partir du nuage de points du lidar aéroporté

Les pratiques d'aménagement forestier doivent être adaptées aux particularités des écosystèmes. L'inventaire de la structure forestière permet de fournir les informations de base pour décrire la diversité des écosystèmes. La télédétection est une solution économique pour mesurer de manière détaillée et extensive la structure forestière. Le lidar (Light Detection and Ranging) aéroporté est une technologie qui permet d'observer la structure tridimensionnelle de la végétation sur de grandes superficies. Cette thèse s'intéresse à trois éléments de la structure forestière : l'âge, la composition et la densité de couvert. Dans le premier chapitre, nous utilisons la distribution verticale des retours lidar ainsi que d'autres indicateurs de structure forestière (hauteur, taux de pénétration des premiers retours, paramètres de distribution Weibull) et de station (altitude, pente, orientation, radiation solaire, indice d'humidité, aire du bassin versant et longueur de pente arrière) pour prédire l'âge moyen des placettes avec une erreur de prédiction de 8.8 ans (R² 0.83, racine de l'erreur quadratique moyenne (RMSE) 19%). Dans le deuxième chapitre, nous avons associé la distribution verticale des retours lidar à l'espèce, l'âge et la densité de couvert en utilisant un GLM fonctionnel et un nouveau test de signifiance non paramétrique graphique permettant d'identifier les variations associées à chacune des variables. Nos résultats indiquent que les trois variables peuvent expliquer jusqu'à 47% de la variation de la distribution verticale des retours lidar. Chaque espèce présentait des caractéristiques discriminantes, mais trois groupes se démarquaient : les peuplements de peuplier faux-tremble affichaient la distribution verticale la plus uniforme ; les peuplements de sapin baumier et de bouleau à papier présentaient une distribution centrée autour de 50% de la hauteur. Les peuplements dominés par les épinettes blanche et noire présentaient une distribution plutôt concentrée à 30% de la hauteur du peuplement. Une augmentation de la fermeture du couvert était associée à une concentration de la distribution autour de 50% de la hauteur du peuplement. L'augmentation de l'âge déplaçait la distribution dans la partie supérieure du peuplement jusqu'à 50-70 ans, puis se stabilisait et redescendait à 90-120 ans. Finalement, nous avons étudié l'influence du seuil de hauteur et de la résolution spatiale de la grille sur la répétabilité des mesures de densité de couvert par lidar aéroporté en utilisant trois survols, dont deux conduits la même année (respectivement 2016 et 2018). En utilisant une mesure d'asymétrie (skewness) et la variance des différences décalées de la densité de couvert, nous avons identifié des mesures qui étaient plus répétables entre les survols. Les résultats montrent que les paramètres suivants étaient optimaux : seuil de hauteur à 3 m, résolution de grille de 25 m (RMSE de 7% et 5% ; biais de 4% et 0% pour les relevés à basse densité de 2016 et 2018). Ces résultats montrent que le lidar est un outil important pour l'enrichissement des données d'inventaire par des données de structure et pourrait contribuer à cibler les pratiques d'aménagement adaptées aux particularités des écosystèmes

Tree species, crown cover, and age as determinants of the vertical distribution of airborne LiDAR returns

Light detection and ranging (LiDAR) provides information on the vertical structure of forest stands enabling detailed and extensive ecosystem study. The vertical structure is often summarized by scalar features and data-reduction techniques that limit the interpretation of results. Instead, we quantified the influence of three variables, species, crown cover, and age, on the vertical distribution of airborne LiDAR returns from forest stands. We studied 5,428 regular, even-aged stands in Quebec (Canada) with five dominant species: balsam fir (Abies balsamea (L.) Mill.), paper birch (Betula papyrifera Marsh), black spruce (Picea mariana (Mill.) BSP), white spruce (Picea glauca Moench) and aspen (Populus tremuloides Michx.). We modeled the vertical distribution against the three variables using a functional general linear model and a novel nonparametric graphical test of significance. Results indicate that LiDAR returns from aspen stands had the most uniform vertical distribution. Balsam fir and white birch distributions were similar and centered at around 50% of the stand height, and black spruce and white spruce distributions were skewed to below 30% of stand height (p<0.001). Increased crown cover concentrated the distributions around 50% of stand height. Increasing age gradually shifted the distributions higher in the stand for stands younger than 70-years, before plateauing and slowly declining at 90-120 years. Results suggest that the vertical distributions of LiDAR returns depend on the three variables studied

Selection of roosting habitat by male Myotis bats in a boreal forest

Male little brown bats (Myotis lucifugus (Le Conte, 1831)) and northern long-eared bats (Myotis septentrionalis (Trouessart, 1897)) often roost under exfoliating bark, within trunks, and within cavities of trees during summer. Current lack of knowledge about the roosting ecology of these species in boreal forest limits our understanding of how they may be affected by logging. The main objective was to identify tree and forest stand features that were selected by bats for roosting within a balsam fir (Abies balsamea (L.) Mill.) – paper birch (Betula papyrifera Marshall) forest of Quebec, Canada. Over 3 years, we captured and fitted radio transmitters to 22 individual bats to locate their roost trees for 7–14 days following release. We measured tree and forest stand features in the field and using light detection and ranging (LiDAR) technology. Roost trees were compared with random trees using generalized linear mixed models. Male Myotis bats selected larger and taller snags, within stands containing a higher proportion of canopy gaps and a larger number of snags compared with random trees. Vegetation clumps of 0.1 ha containing a minimum of 10 snags with a diameter at breast height (DBH) = 10 cm should be maintained to preserve roosting habitat that is used by male Myotis bats in balsam fir – paper birch forests.Les petites chauves-souris brune (Myotis lucifugus (Le Conte, 1831)) et les chauves-souris nordique (Myotis septentrionalis (Trouessart, 1897)) se perchent souvent sous l’écorce exfoliante, a` l’intérieur des troncs et des cavités d’arbres durant l’été. Le manque actuel de connaissances sur l’écologie de perchage de ces espèces dans la forêt boréale limite notre compréhension sur la façon dont elles peuvent être affectées par l’exploitation forestière. L’objectif principal était d’identifier les caractéristiques des arbres et des peuplements forestiers qui étaient sélectionnés par les chauves-souris pour se percher au sein de la sapinière (Abies balsamea (L.) Mill.) a` boulot blanc (Betula papyrifera Marshall) du Québec (Canada). Durant 3 ans, nous avons capturé et équipé 22 chauves-souris de radio-émetteurs pour localiser leurs arbres-gîtes durant 7 a` 14 jours après relâche. Nous avons mesuré les caractéristiques des arbres et du peuplement sur le terrain et en utilisant la technologie LiDAR (light detection and ranging). Les arbres-gites ont été comparés a` des arbres aléatoires en utilisant des modèles mixtes linéaires généralisés. Les chauves-souris mâles du genre Myotis ont choisi des chicots plus larges et plus hauts au sein de peuplements contenant une plus grande proportion de trouées et un plus grand nombre de chicots, comparativement aux arbres aléatoires. Des parcelles de végétation de 0,1 ha comprenant un minimum de 10 chicots avec un diamètre a` hauteur de poitrine (DHP) = 10 cmdevraient être maintenues afin de préserver les sites de perchages des chauves-souris mâles du genre Myotis au sein des sapinières a` bouleau blanc

Neovascular Age-Related Macular Degeneration : A Visual Acuity Model of Natural Disease Progression and Ranibizumab Treatment Effect

Intravitreal ranibizumab is a first-line therapy for neovascular age-related macular degeneration (nAMD), but there is a need to optimize patient outcomes while minimizing treatment burden. Here, we developed an indirect response, nonlinear, mixed effects model of disease progression and drug effect in anti-vascular endothelial growth factor (VEGF) treatment-naïve patients. A total of 1,524 treatment-naïve patients and 29,754 visual acuity observations from the ANCHOR, MARINA, PIER, and EXCITE clinical trials informed the model. The model accurately described natural nAMD disease progression and predicted mean visual acuity gains in the HARBOR study, notably with a 2.0 mg ranibizumab dose not used for model development. Furthermore, individualized treatment regimens were shown by simulation to be a viable alternative to the commonly used pro re nata or fixed monthly dosing regimen approaches. Therefore, this model could be a useful tool to predict the outcomes of different, more patient-tailored treatment regimens in nAMD

Hamiltonian of a spinning test-particle in curved spacetime

Using a Legendre transformation, we compute the unconstrained Hamiltonian of a spinning test-particle in a curved spacetime at linear order in the particle spin. The equations of motion of this unconstrained Hamiltonian coincide with the Mathisson-Papapetrou-Pirani equations. We then use the formalism of Dirac brackets to derive the constrained Hamiltonian and the corresponding phase-space algebra in the Newton-Wigner spin supplementary condition (SSC), suitably generalized to curved spacetime, and find that the phase-space algebra (q,p,S) is canonical at linear order in the particle spin. We provide explicit expressions for this Hamiltonian in a spherically symmetric spacetime, both in isotropic and spherical coordinates, and in the Kerr spacetime in Boyer-Lindquist coordinates. Furthermore, we find that our Hamiltonian, when expanded in Post-Newtonian (PN) orders, agrees with the Arnowitt-Deser-Misner (ADM) canonical Hamiltonian computed in PN theory in the test-particle limit. Notably, we recover the known spin-orbit couplings through 2.5PN order and the spin-spin couplings of type S_Kerr S (and S_Kerr^2) through 3PN order, S_Kerr being the spin of the Kerr spacetime. Our method allows one to compute the PN Hamiltonian at any order, in the test-particle limit and at linear order in the particle spin. As an application we compute it at 3.5PN order.Comment: Corrected typo in the ADM Hamiltonian at 3.5 PN order (eq. 6.20

An aPKC-Exocyst Complex Controls Paxillin Phosphorylation and Migration through Localised JNK1 Activation

The exocyst/aPKC complex controls the spatiotemporal activation of the kinases JNK and ERK at the leading edge of migrating cells and thereby controls the dynamic behaviour of the adhesion protein paxillin during cell migration

hPOC5 is a centrin-binding protein required for assembly of full-length centrioles

Centrin has been shown to be involved in centrosome biogenesis in a variety of eukaryotes. In this study, we characterize hPOC5, a conserved centrin-binding protein that contains Sfi1p-like repeats. hPOC5 is localized, like centrin, in the distal portion of human centrioles. hPOC5 recruitment to procentrioles occurs during G2/M, a process that continues up to the full maturation of the centriole during the next cell cycle and is correlated with hyperphosphorylation of the protein. In the absence of hPOC5, RPE1 cells arrest in G1 phase, whereas HeLa cells show an extended S phase followed by cell death. We show that hPOC5 is not required for the initiation of procentriole assembly but is essential for building the distal half of centrioles. Interestingly, the hPOC5 family reveals an evolutionary divergence between vertebrates and organisms like Drosophila melanogaster or Caenorhabditis elegans, in which the loss of hPOC5 may correlate with the conspicuous differences in centriolar structure

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries