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Although many virtuous leaders are guided by the ideal of prioritizing the needs and welfare of their subordinates, others advance their self-interest at the expense of the people they purport to serve. In this article, we discuss conspiracy theories as a tool that leaders use to advance their personal interests. We propose that leaders spread conspiracy theories in service of four primary goals: 1) to attack opponents; 2) to galvanize followers; 3) to shift blame and responsibility; and 4) to undermine institutions that threaten their power. We argue that authoritarian, populist, and conservative leaders are most likely to spread conspiracy theories during periods of instability.

Objectifs Plusieurs modeles existent pour predire le risque d’envahissement ganglionnaire pelvien mais aussi le risque de recidive biologique apres prostatectomie dans le cancer de prostate localise. Ces scores ont ete valides dans des populations en majorite caucasienne. Peu de donnees sont disponibles pour les populations d’ascendance africaine. L’objectif etait d’evaluer, d’une part, la performance des scores Memorial Sloan Kettering Cancer Centre (MSKCC) et Briganti dans la prediction de l’invasion ganglionnaire, et d’autre part, celle de la classification de D’Amico et des scores de CAPRA et CAPRA-S dans la prediction de la recidive biologique dans deux populations ethno-geographique differentes avec un acces aux soins similaires. Methodes Nous avons realise une etude retrospective bicentrique entre janvier 2000 et decembre 2017 incluant 3249 patients ayant justifie une prostatectomie radicale pour cancer de prostate localise (1830 Afro-antillais et 1419 Caucasiens). Les patients etaient classes par groupe de risque selon les classifications D’Amico et scores CAPRA et CAPRA-S. Parmi eux, 1065 patients justifiaient une lymphadenectomie pelvienne etendue (259 Afro-antillais et 806 Caucasiens). Les scores MSKCC et BRIGANTI 2012 etaient calcules a partir des donnees preoperatoires. La recidive biologique a ete definie par le dosage de 2 PSA consecutifs superieur a 0,2 ng/mL. La performance de ces scores etait testee par l’index C de discrimination de Harrell ou l’analyse de l’aire sous la courbe (AUC) des courbes ROC. Par ailleurs, des courbes de calibration etaient construites illustrant la relation entre les risques estimes et les proportions observees. Resultats L’âge median etait 64 ans (41–81). Le suivi median etait de 3,1 ans (0–22). Au total, 667 (21 %) patients ont presente une recidive biologique : 457 (25 %) Afro-antillais et 210 (15 %) Caucasiens. Le curage ganglionnaire etait positif chez 35 patients (3,3 %) : 15 sur 259 (5,8 %) dans le groupe Afro-antillais et 20 sur 806 (2,5 %) dans le groupe Caucasiens. Toutes les valeurs de C index etait plus faible chez les Afro-antillais par rapport a la cohorte caucasienne, respectivement ; D’Amico (0,62 vs 0,65), CAPRA (0,67 vs 0,68), CAPRA-S (0,69 vs 0,73). La performance de l’outil du MSKCC etait superieure dans le groupe Afro-antillais par rapport au groupe Caucasien (AUC respectivement a 0,69 et 0,65) (Tableau 1). Conclusion La performance des principaux scores predictifs d’envahissement ganglionnaire et de recidive biologique utilises de nos jours n’est pas equivalente au sein de deux populations francaises d’origine ethno-geographique differentes. Dans la population Afro-antillais, nos resultats suggerent d’utiliser le score MSKCC pour predire l’envahissement ganglionnaire et le score CAPRA-S pour predire la recidive biologique.

The de novo pathway of sphingolipid synthesis has been identified recently as a novel means of generating ceramide during apoptosis. Furthermore, it has been suggested that the activation of dihydroceramide synthase is responsible for increased ceramide production through this pathway. In this study, accumulation of ceramide mass in Molt-4 human leukemia cells by the chemotherapy agent etoposide was found to occur primarily due to activation of the de novo pathway. However, when the cells were labeled with a substrate for dihydroceramide synthase in the presence of etoposide, there was no corresponding increase in labeled ceramide. Further investigation using a labeled substrate for serine palmitoyltransferase, the rate-limiting enzyme in the pathway, resulted in an accumulation of label in ceramide upon etoposide treatment. This result suggests that the activation of serine palmitoyltransferase is the event responsible for increased ceramide generation during de novo synthesis initiated by etoposide. Importantly, the ceramide generated from de novo synthesis appears to have a distinct function from that induced by sphingomyelinase action in that it is not involved in caspase-induced poly (ADP-ribose)polymerase proteolysis but does play a role in disrupting membrane integrity in this model system. These results implicate serine palmitoyltransferase as the enzyme controlling de novo ceramide synthesis during apoptosis and begin to define a unique function of ceramide generated from this pathway.

The main goal of the M4 protocol was to evaluate the efficacy of treatment excluding supratentorial radiation in patients with newly diagnosed medulloblastoma. All patients underwent surgical resection and received postoperative chemotherapy. Chemotherapy was adapted to the initial staging and pronostic factors (Group A: good-risk; Group B: poor-risk). Chemotherapy was started early after surgery, and consisted of two courses of the “eight drug in one day” regimen and two courses of high dose methotrexate. Radiotherapy was delayed until 5 (Group B) to 7 (Group A) weeks after the first course of chemotherapy. Radiotherapy was administered only to the posterior fossa and the spinal axis. Only l3 16 patients (18%) are alive and disease-free with a mean follow up of 6 years. The site of progression was supratentorial in 9 out of 13 patients and three patients had spinal and/or cerebrospinal fluid relapses. Only one patient had isolated posterior fossa relapse. The mean time to relapse was 484 days. We conclude that the chemotherapy regimens used in the M4 protocol do not allow the reduction of irradiation fields in patients with cerebellar medulloblastoma. In spite of long-term side effects on neurocognitive functions, supratentorial radiotherapy should remain a major component of medulloblastoma treatment.

Light photolysis of a Rb-THF solution in the presence of cryptate, serving as a complexing agent, results in an ESR line-shape which strongly depends on the light intensity, attributed to a superposition of the photoelectron e − photo and the loose ion pair (Rb cryptate + , e − ). An analysis in terms of the radical pair mechanism is presented.

The lipids of plasma and red cells were separated in four cases of hemolytic anemic syndrome of infancy. The values were compared with those of healthy and of hyperlipemic infants. The lysolecithins of plasma were increased in all four cases of hemolytic anemia of infancy and returned to normal values with the regression of the clinical signs. The lysolecithins of red cells remained unchanged. The lysolecithins of the plasma of hyperlipemic infants were unaltered or slightly elevated.