Abstract. We present photometric sequences in the Johnson's BV and Cousins' R bands in the fields of 10 BL Lacertae objects (BL Lacs) monitored at the Torino Astronomical Observatory. Data were taken during 14 photometric nights from February 1995 to May 1997. The 56 calibrated stars are brighter than V = 16 and can be used as comparison objects in order to derive the BL Lac magnitudes. Finding charts are included for the stars identification.

Abstract. In the course of the blazar monitoring activity at the Torino Astronomical Observatory, we obtained standard BV R magnitudes for 36 stars and standard V R magnitudes for 10 stars in the fields of 9 quasars. Observations were done during 14 photometric nights with the 1.05 m Cassegrain REOSC telescope equipped with a 1242×1152 pixel CCD camera. All stars are brighter than V = 16.6 and are useful comparison objects for the evaluation of the quasar magnitudes.

Radiotherapy is a cornerstone of cancer management. The improvement of spatial dose distribution in the tumor volume by minimizing the dose deposited in the healthy tissues have been a major concern during the last decades. Temporal aspects of dose deposition are yet to be investigated. Laser-plasma-based particle accelerators are able to emit pulsed-proton beams at extremely high peak dose rates (~10 9 Gy/s) during several nanoseconds. The impact of such dose rates on resistant glioblastoma cell lines, SF763 and U87-MG, was compared to conventionally accelerated protons and X-rays. No difference was observed in DNA double-strand breaks generation and cells killing. The variation of the repetition rate of the proton bunches produced an oscillation of the radio-induced cell susceptibility in human colon carcinoma HCT116 cells, which appeared to be related to the presence of the PARP1 protein and an efficient parylation process. Interestingly, when laser-driven proton bunches were applied at 0.5 Hz, survival of the radioresistant HCT116 p53 −/− cells equaled that of its radiosensitive counterpart, HCT116 WT, which was also similar to cells treated with the PARP1 inhibitor Olaparib. Altogether, these results suggest that the application modality of ultrashort bunches of particles could provide a great therapeutic potential in radiotherapy.