Isotopic control of the boron-vacancy spin defect in hexagonal boron nitride

We report on electron spin resonance (ESR) spectroscopy of boron-vacancy (V$_\text{B}^-$) centers hosted in isotopically-engineered hexagonal boron nitride (hBN) crystals. We first show that isotopic purification of hBN with $^{15}$N yields a simplified and well-resolved hyperfine structure of V$_\text{B}^-$ centers, while purification with $^{10}$B leads to narrower ESR linewidths. These results establish isotopically-purified h$^{10}$B$^{15}$N crystals as the optimal host material for future use of V$_\text{B}^-$ spin defects in quantum technologies. Capitalizing on these findings, we then demonstrate optically-induced polarization of $^{15}$N nuclei in h$^{10}$B$^{15}$N, whose mechanism relies on electron-nuclear spin mixing in the V$_\text{B}^-$ ground state. This work opens up new prospects for future developments of spin-based quantum sensors and simulators on a two-dimensional material platform.Comment: 6 pages, 3 figur

Tumor-Induced Cholesterol Efflux from Macrophages Drives IL-4 Mediated Reprogramming and Tumor Progression

Tumor-associated macrophages (TAM) have been shown to have important roles in the malignant progression of various cancers. However, macrophages also posses intrinsic tumoricidal activity and can promote the activity of cytotoxic lymphocytes, but they rapidly adopt an alternative phenotype within tumors, associated with immune-suppression and trophic functions that support tumor growth. The mechanisms that promote TAM polarization in the tumor-microenvironment remain poorly understood, these mechanisms may represent important therapeutic targets to block the tumor-promoting functions of TAM and restore their anti-tumor potential. Here we have characterized TAM in a mouse model of metastatic ovarian cancer. We show that ovarian cancer cells promote membrane-cholesterol efflux and the depletion of lipid rafts from macrophages. Increased cholesterol efflux promoted IL-4 mediated reprogramming while inhibiting IFNγ-induced gene expression. These studies reveal an unexpected role for tumor-induced membrane-cholesterol efflux in driving the IL-4 signaling and the tumor-promoting functions of TAM, while rendering them refractory to pro-inflammatory stimuli. Thus, preventing cholesterol efflux in TAM could represent a novel therapeutic strategy to block pro-tumor functions and restore anti-tumor immunity. Biopharmaceutic

Agrimonde. Agricultures et alimentations du monde en 2050 - Scénarios et défis pour un développement durable - Rapport final, INRA-CIRAD, GIP IFRAI.

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Saving Jobs, Promoting Democracy: Worker Co-Operatives

peer reviewedThe article examines transformative alternatives that may offer pathways to a more participative, sustainable and equitable social order. It focuses on one form of alternative, worker-owned co-operatives, and argues this existing form of democratic and economic relations has already proven capacity to generate more equitable socio-economic outcomes and residual social capital. The worker-owned model is located within an ideological framework that focuses on the inherent democratising principles of their praxis that can in the right circumstances underpin firm strategic foundations for radical social change. It examines the development of worker-owned co-ops in Ireland north and south and the obstacles that need to be overcome to make these a more feasible and common form of economic ownership. Reflecting on the current debate in Ireland it argues such co-ops cannot work effectively without a secure legal framework governing their status and softer supports including entrepreneurship development, leadership training, market research, accessing loan finance and grant aid, inter-cooperative networking and federation building. The article poses workers’ co-operatives as sites of political struggle and consciousness, expressed in co-operatives’ core values including sovereignty of labour, the subordinate nature of capital, democracy, inter-cooperation and sustainability, and in tangible democratic experiences and transformative praxis