Calibrating LISA Pathfinder raw data into femto-g differential accelerometry

LISA Pathfinder is an in-flight test of the local sources of acceleration noise in LISA. The acceleration noise level in LISA Pathfinder is measured by the residual differential acceleration Δg between the two test masses once the coupling to the spacecraft motion has been removed. The full process from raw data to Δg passes through a series of calibration experiments and different data elaboration procedure which are thoroughly used during the mission and represent the baseline for any other further investigation. © Published under licence by IOP Publishing Ltd

Tumor hypoxia and radiotherapy: A major driver of resistance even for novel radiotherapy modalities

Hypoxia in solid tumors is an important predictor of poor clinical outcome to radiotherapy. Both physicochemical and biological processes contribute to a reduced sensitivity of hypoxic tumor cells to ionizing radiation and hypoxia-related treatment resistances. A conventional low-dose fractionated radiotherapy regimen exploits iterative reoxygenation in between the individual fractions, nevertheless tumor hypoxia still remains a major hurdle for successful treatment outcome. The technological advances achieved in image guidance and highly conformal dose delivery make it nowadays possible to prescribe larger doses to the tumor as part of single high-dose or hypofractionated radiotherapy, while keeping an acceptable level of normal tissue complication in the co-irradiated organs at risk. However, we insufficiently understand the impact of tumor hypoxia to single high-doses of RT and hypofractionated RT. So-called FLASH radiotherapy, which delivers ionizing radiation at ultrahigh dose rates (> 40 Gy/sec), has recently emerged as an important breakthrough in the radiotherapy field to reduce normal tissue toxicity compared to irradiation at conventional dose rates (few Gy/min). Not surprisingly, oxygen consumption and tumor hypoxia also seem to play an intriguing role for FLASH radiotherapy. Here we will discuss the role of tumor hypoxia for radiotherapy in general and in the context of novel radiotherapy treatment approaches

Gravitational wave scintillation by a stellar cluster

The diffraction effects on gravitational waves propagating through a stellar cluster are analyzed in the relevant approximation of Fresnel diffraction limit. We find that a gravitational wave scintillation effect - similar to the radio source scintillation effect - comes out naturally, implying that the gravitational wave intensity changes in a characteristic way as the observer moves.Comment: 9 pages, in press in IJMP

Long-term placement of continuous popliteal nerve block catheter for management of a wounded patient in a combat field environment: A case report

Continuous peripheral nerve block is a relevant part of multimodal treatment of postoperative pain. In this context the continuous popliteal nerve block is described as an option for postoperative pain management for surgical procedures on the leg, and particularly on the ankle and foot. We applied continuous popliteal nerve block for different types of anesthesia and postoperative pain management via the same catheter. No clear evidence of this specific use has been described in the literature. A 38 year-old patient wounded in combat with a displaced fracture of left tibia and extensive loss of substance needed orthopedic surgeries as well as several reconstructive procedures. A continuous popliteal nerve block was applied via ultrasound-guided catheter for anesthesia at different times, and postoperative pain control for all surgical procedures. The continuous popliteal nerve block and its long-term positioning, of non-common evidence in literature, was utilized to treat a poly-traumatized patient, thereby avoiding repeated general anesthesia and opioid use and their adverse effects. This technique, within a complicated combat field environment, was demonstrated to be clinically effective with high patient satisfaction

Time Delay Interferometry combinations as instrument noise monitors for LISA

The LISA mission will likely be a signal dominated detector, such that one challenge is the separation of the different astrophysical sources, and to distinguish between them and the instrumental noise. One of the goals of LISA is to probe the early Universe by detecting stochastic GW backgrounds. As correlation with other detectors is not possible for LISA, discrimination of such a GW background from the instrumental noise requires a good estimate of the latter. To this purpose we have revisited Time Delay Interferometry (TDI) to look for new TDI signal combinations that fulfill the laser frequency noise suppression requirements. We illustrate that it is possible to do a linear combination of these TDI channels to find special null-combinations that suppress gravitational waves and mainly carry information about instrumental noise. We find that there exist many null-combinations that show different sensitivities to gravitational waves, some of which seem more suitable than the traditional T combination for estimating test-mass acceleration noise. In an idealised LISA configuration, they are all sensitive to a particular linear combination of the six test-masses acceleration, similar to a rigid rotation of the LISA triangle. In the following article, we illustrate what are the noise properties that can be extracted by monitoring these interferometry signals and discuss the implication of these findings for the detection of stochastic GW backgrounds

Castiglione a Milano

The essay aims to deepen the relation between Baldassarre Castiglione and the city of Milan. The first paragraph deals with the period of study spent in the capital of the duchy, where the author of the Cortegiano, still a teenager, and guest of his uncle senator, was able to learn about the profession and the language of diplomacy and to meet important figures of the humanistic and artistic culture of the city, who will appear in the pages of the Dialogue. Based on some passages from his correspondence, the second paragraph recounts Baldassarre's travels to Milan on the occasion of various military and diplomatic missions. The third paragraph highlights the specific references to the city found in his letters. The last section provides a textual and linguistic perspective, examining the famous letter to Iacomo Boschetto of 8 October 1499, written on the occasion of the entry of the King of France to Milan. It is a precious description of a parade from which a layered lexicon emerges, with names of weapons, clothes, and styles, which shows the richness of the language and of the courtesan letters, a first Italian sectorial dictionary.   Il saggio vuole approfondire il rapporto tra Baldassarre Castiglione e Milano: un primo paragrafo tratta del periodo di studio trascorso nella capitale del ducato, dove l’autore del Cortegiano ancora adolescente, ospite dello zio senatore, ebbe modo di conoscere la professione e la lingua della diplomazia e di incontrare personaggi di rilievo della cultura umanistica e artistica della città, che compariranno nelle pagine del Dialogo. Il secondo paragrafo racconta attraverso alcuni brani dell’epistolario i viaggi di Baldassarre a Milano, in occasione di diverse missioni militari e diplomatiche; mentre il terzo riporta i riferimenti alla città reperibili nelle sue lettere. Infine, una prospettiva testuale e linguistica: viene presa in esame la celebre lettera a Iacomo Boschetto dell’8 ottobre 1499, scritta in occasione dell’entrate del re di Francia a Milano. Si tratta di una preziosa descrizione di una parata da cui emerge un lessico stratificato, con nomi di armi, vesti e fogge, che mostra la ricchezza della lingua e della epistolografia cortigiana, un primo vocabolario settoriale italiano.