On the computation of preliminary orbits for Earth satellites with radar observations

We introduce a new method to perform preliminary orbit determination for satellites on low Earth orbits (LEO). This method works with tracks of radar observations: each track is composed by $nge 4$ topocentric position vectors per pass of the satellite, taken at very short time intervals. We assume very accurate values for the range $ho$, while the angular positions (i.e. the line of sight, given by the pointing of the antenna) are less accurate. We wish to correct the errors in the angular positions already in the computation of a preliminary orbit. With the information contained in a pair of radar tracks, using the laws of the two-body dynamics, we can write 8 equations in 8 unknowns. The unknowns are the components of the topocentric velocity orthogonal to the line of sight at the two mean epochs of the tracks, and the corrections $Delta$ to be applied to the angular positions. We take advantage of the fact that the components of $Delta$ are typically small. We show the results of some tests, performed with simulated observations, and compare this method with Gibbs' and the Keplerian integral

Prevention of suicide behind bars: first Italian results

Background: The reduction of suicides in jails and prisons is an international priority and, after the publication of a report about the necessity to prevent the suicide risk, in Tuscany (Italy) was created a new biphasic protocol. The aim of our study was to show the preliminary results after the introduction of this protocol in the Penitentiary of Pistoia. Methods: We conducted an ecological pilot study from April to December 2016. In the Penitentiary of Pistoia, a multidisciplinary staff collected socio-demographic and clinical information of the new inmates, and estimated the suicide risk administering the Arboleda-Florez Checklist. Results: Ninety-three new prisoners (all males) were conducted in the Penitentiary of Pistoia: 12 (12.90%) came from another prison; 81 (87.09%) were free before the arrival. 16 (17.2%) were homeless, 52 (55.91%) were unemployed, 1 (1.07%) was retired. 32 declared to use drugs; 7 of them declared also the alcohol abuse. Three detainees claimed only the alcohol abuse. 9 prisoners were already assisted by the Service for Drug Addiction when they have been arrested. 77 (82.79%) were positive for at least 1 item of the Arboleda-Florez Checklist. The measures of great surveillance were disposed for 67 prisoners. Three were the measures of Greatest Surveillance for high suicide risk. 13 inmates needed a specific pharmacological treatment prescribed by a psychiatrist. A therapy for mild anxiety and insomnia was prescribed in 29 cases: 21 after the first visit; 8 later. A psychological support was furnished to 23 prisoners who didn’t need the prescription of psychotropic medication, but only an emotional support. Conclusions: Our pilot study showed that the biphasic protocol could be able to manage in a good way the suicide risk, in fact no suicide occurred in the examined period of time. However, studies covering longer periods of time and involving other realities are needed to give more reliable results about its real efficacy

Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

Objectives: Few studies have analyzed factors associated with delirium subtypes. In this study, we investigate factors associated with subtypes of delirium only in patients with dementia to provide insights on the possible prevention and treatments. Design: This is a cross-sectional study nested in the “Delirium Day” study, a nationwide Italian point-prevalence study. Setting and Participants: Older patients admitted to 205 acute and 92 rehabilitation hospital wards. Measures: Delirium was evaluated with the 4-AT and the motor subtypes with the Delirium Motor Subtype Scale. Dementia was defined by the presence of a documented diagnosis in the medical records and/or prescription of acetylcholinesterase inhibitors or memantine prior to admission. Results: Of the 1057 patients with dementia, 35% had delirium, with 25.6% hyperactive, 33.1% hypoactive, 34.5% mixed, and 6.7% nonmotor subtype. There were higher odds of having venous catheters in the hypoactive (OR 1.82, 95% CI 1.18-2.81) and mixed type of delirium (OR 2.23, CI 1.43-3.46), whereas higher odds of urinary catheters in the hypoactive (OR 2.91, CI 1.92-4.39), hyperactive (OR 1.99, CI 1.23-3.21), and mixed types of delirium (OR 2.05, CI 1.36-3.07). We found higher odds of antipsychotics both in the hyperactive (OR 2.87, CI 1.81-4.54) and mixed subtype (OR 1.84, CI 1.24-2.75), whereas higher odds of antibiotics was present only in the mixed subtype (OR 1.91, CI 1.26-2.87). Conclusions and Implications: In patients with dementia, the mixed delirium subtype is the most prevalent followed by the hypoactive, hyperactive, and nonmotor subtype. Motor subtypes of delirium may be triggered by clinical factors, including the use of venous and urinary catheters, and the use of antipsychotics. Future studies are necessary to provide further insights on the possible pathophysiology of delirium in patients with dementia and to address the optimization of the management of potential risk factors