MIMAC-He3 : MIcro-tpc MAtrix of Chambers of He3

The project of a micro-TPC matrix of chambers of He3 for direct detection of non-baryonic dark matter is outlined. The privileged properties of He3 are highlighted. The double detection (ionization - projection of tracks) will assure the electron-recoil discrimination. The complementarity of MIMAC-He3 for supersymmetric dark matter search with respect to other experiments is illustrated. The modular character of the detector allows to have different gases to get A-dependence. The pressure degreee of freedom gives the possibility to work at high and low pressure. The low pressure regime gives the possibility to get the directionality of the tracks. The first measurements of ionization at very few keVs for He3 in He4 gas are described

Fractures After Denosumab Discontinuation: A Retrospective Study of 797 Cases.

A rebound of osteoclast activity during the 2 years after a treatment or prevention of osteoporosis with denosumab (Dmab) leads to an increased risk of vertebral fractures (VFs). We attempted to identify the risk factors for these VF and to examine the protective role of bisphosphonates. For that, 22 specialists in Switzerland provided data of unselected patients, treated with denosumab for osteoporosis or breast cancer without metastases under aromatase inhibitors, who have received at least two injections of Dmab, with at least 1 year of follow-up after discontinuation. The questionnaire covered separately the periods before, during, and after Dmab treatment, and registered clinical, radiological, and lab data. For the analysis of the risk factors, the main outcomes were the time to the first VF after the treatment, the presence of multiple VFs (MVFs), and the number of VFs. The incidence of VF was 16.4% before, 2.2% during, and 10.3% after the treatment with Dmab. The risk of VF after Dmab discontinuation was associated with an increased risk of non-vertebral fractures. The pretreatment predictors of the post-treatment fracture risk were a parental hip fracture and previous VFs. Further risk factors appeared later, such as low total hip bone mineral density (BMD) during and after denosumab, increased bone resorption markers, and the loss of total hip BMD after the denosumab. Treatment with bisphosphonates, especially after Dmab, had a protective effect. Bisphosphonates given before Dmab did not further decrease the risk of VF in cases who got bisphosphonates after Dmab. This study shows that the risk of VF is poorly predictable before the prescription of denosumab. But during and after the treatment, bone resorption markers and BMD have a significant predictive value. Bisphosphonates after the treatment with denosumab are protective against VFs. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)

The properties of asteroid (2867) Steins from Spitzer observations and OSIRIS shape reconstruction

We report on the thermal properties and composition of asteroid (2867) Steins derived from an analysis of new Spitzer Space Telescope (SST) observations performed in March 2008, in addition to previously published SST observations performed in November 2005. We consider the three-dimensional shape model and photometric properties derived from OSIRIS images obtained during the flyby of the Rosetta spacecraft in September 2008, which we combine with a thermal model to properly interpret the observed SST thermal light curve and spectral energy distributions. We obtain a thermal inertia in the range 100\pm50 JK-1m-2s-1/2 and a beaming factor (roughness) in the range 0.7-1.0. We confirm that the infrared emissivity of Steins is consistent with an enstatite composition. The November 2005 SST thermal light curve is most reliably interpreted by assuming inhomogeneities in the thermal properties of the surface, with two different regions of slightly different roughness, as observed on other small bodies, such as the nucleus of comet 9P/Tempel 1. Our results emphasize that the shape model is important to an accurate determination of the thermal inertia and roughness. Finally, we present temperature maps of Steins, as seen by Rosetta during its flyby, and discuss the interpretation of the observations performed by the VIRTIS and MIRO instruments

The nucleus of 103P/Hartley 2, target of the EPOXI mission

103P/Hartley 2 was selected as the target comet for the Deep Impact extended mission, EPOXI, in October 2007. There have been no direct optical observations of the nucleus of this comet, as it has always been highly active when previously observed. We aimed to recover the comet near to aphelion, to a) confirm that it had not broken up and was in the predicted position, b) to provide astrometry and brightness information for mission planning, and c) to continue the characterisation of the nucleus. We observed the comet at heliocentric distances between 5.7 and 5.5 AU, using FORS2 at the VLT, at 4 epochs between May and July 2008. We performed VRI photometry on deep stacked images to look for activity and measure the absolute magnitude and therefore estimate the size of the nucleus. We recovered the comet near the expected position, with a magnitude of m_R = 23.74 \pm 0.06 at the first epoch. The comet had no visible coma, although comparison of the profile with a stellar one showed that there was faint activity, or possibly a contribution to the flux from the dust trail from previous activity. This activity appears to fade at further epochs, implying that this is a continuation of activity past aphelion from the previous apparition rather than an early start to activity before the next perihelion. Our data imply a nucleus radius of \le 1 km for an assumed 4% albedo; we estimate a ~6% albedo. We measure a colour of (V-R) = 0. 26 \pm 0.09.Comment: 5 pages, 4 figures, accepted for publication in A&

Differential Blood Counts Do Not Consistently Predict Clinical Measurements of Bone Mineral Density and Microarchitecture at Homeostasis.

The hematopoietic stem cell niche constitutes a complex bone marrow (BM) microenvironment. Osteoporosis is characterized by both reduced bone mineral density (BMD) and microarchitectural deterioration, constituting the most frequent alteration of the BM microenvironment. It is unclear to which extent modifications of the BM microenvironment, including in the context of osteoporosis, influence blood cell production. We aimed to describe the association between lumbar spine and total hip BMD and microarchitecture (assessed by trabecular bone score [TBS]) and differential blood counts. Data were collected at two time points from 803 (first assessment) and 901 (second assessment) postmenopausal women participating in the CoLaus/OsteoLaus cohort, a population-based sample in Lausanne, Switzerland. Participants with other active disease or treatment that could influence hematopoiesis or osteoporosis were excluded. Bivariate and multivariate associations between each peripheral blood cell count and BMD or TBS were performed. Additionally, participants in the highest BMD and TBS tertiles were compared with participants in the lowest BMD and TBS tertiles. At first assessment, only neutrophils were significantly different in the lowest BMD and TBS tertile (3.18 ± 0.09 versus 3.47 ± 0.08 G/L, p = 0.028). At the second assessment, leucocytes (5.90 ± 0.11 versus 5.56 ± 0.10 G/L, p = 0.033), lymphocytes (1.87 ± 0.04 versus 1.72 ± 0.04 G/L p = 0.033), and monocytes (0.49 ± 0.01 versus 0.46 ± 0.1 G/L, p = 0.033) were significantly different. Power analysis did not identify quasi-significant associations missed due to sample size. Although significant associations between blood counts and BMD or TBS were found, none was consistent across bone measurements or assessments. This study suggests that, at homeostasis and in postmenopausal women, there is no clinically significant association between the osteoporotic microenvironment and blood production output as measured by differential blood counts. In the context of conflicting reports on the relationship between osteoporosis and hematopoiesis, our study represents the first prospective two time-point analysis of a large, homogenous cohort at steady state. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Millimetre continuum observations of comet C/2009 P1 (Garradd)

Little is known about the physical properties of the nuclei of Oort cloud comets. Measuring the thermal emission of a nucleus is one of the few means for deriving its size and constraining some of its thermal properties. We attempted to measure the nucleus size of the Oort cloud comet C/2009 P1 (Garradd). We used the Plateau de Bure Interferometer to measure the millimetric thermal emission of this comet at 157 GHz (1.9 mm) and 266 GHz (1.1 mm). Whereas the observations at 266 GHz were not usable due to bad atmospheric conditions, we derived a 3-sigma upper limit on the comet continuum emission of 0.41 mJy at 157 GHz. Using a thermal model for a spherical nucleus with standard thermal parameters, we found an upper limit of 5.6 km for the radius. The dust contribution to our signal is estimated to be negligible. Given the water production rates measured for this comet and our upper limit, we estimated that Garradd was very active, with an active fraction of its nucleus larger than 50%.Comment: Accepted for publication in Astronomy & Astrophysics. 5 pages, 2 figure

Prediction of potentially avoidable readmission risk in a division of general internal medicine.

The 30-day post-discharge readmission rate is a quality indicator that may reflect suboptimal care. The computerised algorithm SQLape® can retrospectively identify a potentially avoidable readmission (PARA) with high sensitivity and specificity. We retrospectively analysed the hospital stays of patients readmitted to the Department of Internal Medicine of the CHUV (Centre Hospitalier Universitaire Vaudois) in order to quantify the proportion of PARAs and derive a risk prediction model. All hospitalisations between January 2009 and December 2011 in our division of general internal medicine were analysed. Readmissions within 30 days of discharge were categorised using SQLape®. The impact on PARAs was tested for various clinical and nonclinical factors. The performance of the developed model was compared with the well-validated LACE and HOSPITAL scores. From a total of 11 074 hospital stays, 777 (7%) were followed with PARA within 30 days. By analysing a group of 6729 eligible stays, defined in particular by the patients' returning to their place of residence (home or residential care centre), we identified the following risk factors: ≥1 hospitalisation in the year preceding index admission, Charlson score >1, active cancer, hyponatraemia, length of stay >11 days, prescription of ≥15 different medications during the stay. These variables were used to derive a risk prediction model for PARA with a good discriminatory power (C-statistic 0.70) and calibration (p = 0.69). Patients were then classified as low (16.4%), intermediate (49.4%) or high (34.2%) risk of PARA. The estimated risk of PARA for each category was 3.5%, 8.7% and 19.6%, respectively. The LACE and the HOSPITAL scores were significantly correlated with the PARA risk. The discriminatory power of the LACE (C-statistic 0.61) and the HOSPITAL (C-statistic 0.54) were lower than our model. Our model identifies patients at high risk of 30-day PARA with a good performance. It could be used to target transition of care interventions. Nevertheless, this model should be validated on more data and could be improved with additional parameters. Our results highlight the difficulty to generalise one model in the context of different healthcare systems

MIMAC : A Micro-TPC Matrix of Chambers for direct detection of Wimps

The project of a micro-TPC matrix of chambers of He3 and CF4 for direct detection of non-baryonic dark matter is outlined. The privileged properties of He3 are highlighted. The double detection (ionization - projection of tracks) will assure the electron-recoil discrimination. The complementarity of MIMAC for supersymmetric dark matter search with respect to other experiments is illustrated.The modular character of the detector allows to have different gases to get A-dependence. The pressure degreee of freedom gives the possibility to work at high and low pressures. The low pressure regime gives the possibility to get the directionality of the tracks. The first measurements of ionization at very few keVs for He3 in CF4 gas are described.Comment: to be published in the Proceedings of the Third Symposium on Large TPCs for Low Energy Rare Event Detection, 11 - 12 December 2006, Pari