Elimination of extremal index zeroes from generic paths of closed 1-forms

Let $\alpha$ be a Morse closed $1$-form of a smooth $n$-dimensional manifold $M$. The zeroes of $\alpha$ of index $0$ or $n$ are called \emph{centers}. It is known that every non-vanishing de Rham cohomology class $u$ contains a Morse representative without centers. The result of this paper is the one-parameter analogue of the last statement: every generic path $(\alpha_t)_{t\in [0,1]}$ of closed $1$-forms in a fixed class $u\neq 0$ such that $\alpha_0, \alpha_1$ have no centers, can be modified relatively to its extremities to another such path $(\beta_t)_{t\in [0,1]}$ having no center at all.Comment: Mathematische Zeitschrift (2014) 25 p

Effectiveness of video-assisted debriefing versus oral debriefing in simulation-based interdisciplinary health professions education: A randomized trial

* Corresponding author at: Department of Nursing, Faculty of Health Sciences, University of Granada, Granada 18016, Spain. E-mail address: [email protected] (R. Gil-Gutiérrez).Aim We aimed to compare the debriefing experience, simulation assessment, reflection, anxiety and simulation satisfaction of using oral debriefing versus video-assisted debriefing after a simulated clinical session in an interdisciplinary cohort of health sciences students. Background Debriefing is a reflective process that takes place after a clinical simulation and that can be performed either in a traditional way (oral) or using video-assisted debriefing. Design A randomized controlled trial was conducted in 143 health sciences students (35.7% male, 61.5% female). Methods The simulation scenario was designed to evaluate the procedure for donning and doffing personal protective equipment. Differences in debriefing experience, simulation assessment, reflection, anxiety and satisfaction were assessed. Results Regarding debriefing experience, significant differences were observed for the category “learning” (34.9 (6.13) vs. 36.7 (3.89); p = 0.039). For simulation assessment, significantly higher scores for all categories were identified in video-assisted debriefing compared with oral debriefing (p<0.001). There were also significant differences between the oral debriefing versus video-assisted debriefing for the overall score of reflection ability (86.97 (10.55) vs. 90.74 (9.67); p=0.028) as well as for the category “reflective communication” (24.72 (3.77) vs 26.04 (4.07); p=0.047). Perceived satisfaction was significantly higher in the video-assisted debriefing group compared with oral debriefing group (p <0.001). For anxiety, no significant differences were observed between debriefing groups. Conclusion Video-assisted debriefing after a simulated clinical session improves debriefing experience, simulation assessment, reflection and simulation satisfaction, but does not increase anxiety compared with oral debriefing among health sciences students.*Funding for open access charge: Univeresidad de Granada/CBUA

PSA Kinetics as Prognostic Markers of Overall Survival in Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Abiraterone Acetate

Background: Abiraterone acetate (AA) is widely used in the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). However, a significant percentage of patients will still progress, highlighting the need to identify patients more likely to benefit from AA. Parameters linked to prostate-specific antigen (PSA) kinetics are promising prognostic markers. We have examined clinical and PSA-related factors potentially asso- ciated with overall survival (OS) in patients treated with AA. Methods: Between 2011 and 2014, 104 patients with mCRPC treated with AA after progression to docetaxel at centers of the Catalan Institute of Oncology were included in this retrospective study. Patients were assessed monthly. Baseline characteristics and vari- ables related to PSA kinetics were included in univariate and multivariate analyses of OS. Results: Median OS was 16.4 months (range 12.4-20.6) for all patients. The univariate analysis identified the following baseline characteristics as significantly associated with OS: ECOG PS, location of metastases, time between starting androgen deprivation therapy and starting AA, time between stopping docetaxel treatment and starting AA, neutrophil- lymphocyte ratio (NLR), alkaline phosphatase levels, and PSA levels. Factors related to PSA kinetics associated with longer OS were PSA response >50%, early PSA response (>30% decline at four weeks), PSA decline >50% at week 12, PSA nadir 140 days, the combination of PSA nadir and time to PSA nadir, and low end-of- treatment PSA levels. The multivariate analysis identified ECOG PS (HR 37.46; p<0.001), NLR (HR 3.7; p<0.001), early PSA response (HR 1.22; p=0.002), and time to PSA nadir (HR 0.39; p=0.002) as independent prognostic markers. Conclusion: Our results indicate an association between PSA kinetics, especially early PSA response, and outcome to AA after progression to docetaxel. Taken together with other factors, lack of an early PSA response could identify patients who are unlikely to benefit from AA and who could be closely monitored with a view to offering alternative therapies

Identifying SARS-CoV-2 'memory' NK cells from COVID-19 convalescent donors for adoptive cell therapy

COVID-19 disease is the manifestation of syndrome coronavirus 2 (SARS-CoV-2) infection, which is causing a worldwide pandemic. This disease can lead to multiple and different symptoms, being lymphopenia associated with severity one of the most persistent. Natural killer cells (NK cells) are part of the innate immune system, being fighting against virus-infected cells one of their key roles. In this study, we determined the phenotype of NK cells after COVID-19 and the main characteristic of SARS-CoV-2-specific-like NK population in the blood of convalescent donors. CD57+ NKG2C+ phenotype in SARS-CoV-2 convalescent donors indicates the presence of 'memory'/activated NK cells as it has been shown for cytomegalovirus infections. Although the existence of this population is donor dependent, its expression may be crucial for the specific response against SARS-CoV-2, so that, it gives us a tool for selecting the best donors to produce off-the-shelf living drug for cell therapy to treat COVID-19 patients under the RELEASE clinical trial (NCT04578210)

Contribution à une théorie de Morse-Novikov à paramètre

The framework of this study is a closed manifold of dimension at least six that is provided with a nonzero De Rham cohomology class. The aim is to create tools to address the next problem: two closed non-singular (without zeroes) 1-forms in the fixed class are always isotopic? The general answer to the question is no, and a K-theoretical obstruction is expected. It is always possible to connect two non-singular closed 1-forms by a path that remains in the cohomology class; the isotopy of the two ends of the path is equivalent to find a relative homotopy of the path to another one made of non-singular 1-forms only. We introduce two kinds of pseudo-gradients for each positive number L: those with an L-elementary link and those that we call L-transverse. They form a class of vector fields adapted to the 1-forms that allows to do an algebraic reading associated with the path. This reading is similar to that made in the theory of Hatcher-Wagoner who treated the isotopy problem of real-valued functions without critical points. We manage to find L, a number large enough to deform a path of 1-forms with only two critical indices into another one with an L-transverse equipment in normal form. The zeroes of such a path that are born together, die together and moreover, the associated Cerf-Novikov graphic is closed : the cited algebraic reading belongs to some K_2, which is the starting point for the definition of an obstruction for two non-singular closed 1-forms to be isotopic.Le cadre de cette étude est une variété fermée de dimension au moins six qui est munie d'une classe de cohomologie de De Rham non-nulle. L'objectif de la thèse est de créer des outils pour répondre au problème de savoir si deux 1-formes fermées non-singulières (sans zéro) dans la classe fixée sont toujours isotopes. La réponse générale à la question est non, et une obstruction de type K-théorique est attendue. Il est toujours possible de relier deux 1-formes fermées non singulières par un chemin qui reste dans la classe de cohomologie ; l'isotopie des extrêmes du chemin équivaut à déformer le chemin par une homotopie relative en un autre constitué de 1-formes non-singulières. On introduit deux sortes de pseudo-gradients pour chaque nombre L positif : ceux avec une liaison L-élémentaire et ceux que nous appelons L-transverses. Ils forment une classe de champs de vecteurs adaptés aux 1-formes qui permettent de faire une lecture algébrique associée au chemin. Cette lecture est analogue à celle qui est faite dans la théorie de Hatcher-Wagoner qui traitait le problème d'isotopie pour les fonctions à valeurs réelles sans point critique. On réussit à trouver un nombre L assez grand pour déformer un chemin de 1-formes à deux indices critiques en un autre chemin muni d'un équipement L-transverse qui est sous forme normale. Les zéros d'un tel chemin de 1-formes qui sont nés ensemble, s'éliminent ensemble et de plus le graphique de Cerf-Novikov associé se ferme : la lecture algébrique citée appartient à un certain K_2, ce qui est au point de départ de la définition d'une obstruction à l'isotopie des 1-formes fermées non-singulières

A geometric Morse-Novikov complex with infinite series coefficients

International audienceLet M be a closed n-dimensional manifold, n > 2, whose first real cohomology group H 1 (M ; R) is non-zero. We present a general method for constructing a Morse 1-form α on M , closed but non-exact, and a pseudo-gradient X such that the differential ∂ X of the Novikov complex of the pair (α, X) has at least one incidence coefficient which is an infinite series. This is an application of our previous study of the homoclinic bifurcation of pseudo-gradients of multivalued Morse functions

Contribution à une théorie de Morse-Novikov à paramètre

Le cadre de cette étude est une variété fermée de dimension au moins six qui est munie d'une classe de cohomologie de De Rham non-nulle. L'objectif de la thèse est de créer des outils pour répondre au problème de savoir si deux 1-formes fermées non-singulières (sans zéro) dans la classe fixée sont toujours isotopes. La réponse générale à la question est non, et une obstruction de type K-théorique est attendue. Il est toujours possible de relier deux 1-formes fermées non singulières par un chemin qui reste dans la classe de cohomologie ; l'isotopie des extrêmes du chemin équivaut à déformer le chemin par une homotopie relative en un autre constitué de 1-formes non-singulières. On introduit deux sortes de pseudo-gradients pour chaque nombre L positif : ceux avec une liaison L-élémentaire et ceux que nous appelons L-transverses. Ils forment une classe de champs de vecteurs adaptés aux 1-formes qui permettent de faire une lecture algébrique associée au chemin. Cette lecture est analogue à celle qui est faite dans la théorie de Hatcher-Wagoner qui traitait le problème d'isotopie pour les fonctions à valeurs réelles sans point critique. On réussit à trouver un nombre L assez grand pour déformer un chemin de 1-formes à deux indices critiques en un autre chemin muni d'un équipement L-transverse qui est sous forme normale. Les zéros d'un tel chemin de 1-formes qui sont nées ensemble, s'éliminent ensemble et de plus le graphique de Cerf-Novikov associé se ferme : la lecture algébrique citée appartient à un certain K2, ce qui est au point de départ de la définition d'une obstruction à l'isotopie des 1-formes fermées non-singulières.The framework of this study is a closed manifold of dimension at least six that is provided with a nonzero De Rham cohomology class. The aim is to create tools to address the next problem : two closed non-singular (without zeroes) 1-forms in the fixed class are always isotopic ? The general answer to the question is no, and a K-theoretical obstruction is expected. It is always possible to connect two non-singular closed 1-forms by a path that remains in the cohomology class ; the isotopy of the two ends of the path is equivalent to find a relative homotopy of the path to another one made of non-singular 1-forms only. We introduce two kinds of pseudo-gradients for each positive number L : those with an L-elementary link and those that we call L-transverse. They form a class of vector fields adapted to the 1-forms that allows to do an algebraic reading associated with the path. This reading is similar to that made in the theory of Hatcher-Wagoner who treated the isotopy problem of real-valued functions without critical points. We manage to find L, a number large enough to deform a path of 1-forms with only two critical indices into another one with an L-transverse equipment in normal form. The zeroes of such a path that are born together, die together and moreover, the associated Cerf-Novikov graphic is closed : the cited algebraic reading belongs to some K2, which is the starting point for the definition of an obstruction for two non-singular closed 1-forms to be isotopic.NANTES-BU Sciences (441092104) / SudocSudocFranceF