Use of MESSENGER radioscience data to improve planetary ephemeris and to test general relativity

The current knowledge of Mercury orbit has mainly been gained by direct radar ranging obtained from the 60s to 1998 and by five Mercury flybys made by Mariner 10 in the 70s, and MESSENGER made in 2008 and 2009. On March 18, 2011, MESSENGER became the first spacecraft to orbit Mercury. The radioscience observations acquired during the orbital phase of MESSENGER drastically improved our knowledge of the orbit of Mercury. An accurate MESSENGER orbit is obtained by fitting one-and-half years of tracking data using GINS orbit determination software. The systematic error in the Earth-Mercury geometric positions, also called range bias, obtained from GINS are then used to fit the INPOP dynamical modeling of the planet motions. An improved ephemeris of the planets is then obtained, INPOP13a, and used to perform general relativity tests of PPN-formalism. Our estimations of PPN parameters (beta and gamma?) are more stringent than previous results.Comment: Accepted by A&

A study on patterns of needle - stick injuries among gynaecologic and general surgeons in open surgery

Background: An estimated 3,84,000 percutaneous injuries are reported by HCW in hospitals in the United States each year, placing them at risk of exposure to HIV, HBV, or HCV. Suture needles have been identified as the most frequent cause of injury. They are involved in as many as 44% of such injuries. This study is designed to note the NSI in major gynaecological procedures and surgical procedures using conventional method (CM) versus (VS) use of HK.Methods: Study was conducted over a period of 12 months from January 2017 to December 2017. 60 patients were included in this study and were divided into 2 groups A and B with 30 patients in each group. Group A was major surgery performed by conventional method; Group B was major surgery performed by using harmonic knife. NSI in two groups were studied and analyzed.Results: Most of the operated patients were between 41-50 years age group. 16.6% procedures were emergency and 83.3% were elective. NSI in conventional surgery was 63.3% in the surgeon and 33.3% with harmonic knife. There were 13.3% NSI in first assistant in conventional surgery and 23.3% in harmonic scalpel group. No such injuries were reported by second assistant in either group. Injuries were more in non-dominant hand in either groups in the surgeon and first assistant.Conclusions: It is concluded that NSI are common in surgeons and first assistant. Such injuries are more in non-dominant hand and in procedures where there is little exposure like vaginal hysterectomy. Use of innovative technologies like harmonic scalpel may be useful

Relationship between pregnancy rate and number of intrauterine insemination cycles during the study of comparative efficacy of letrozole and clomiphene citrate adjuvants to gonadotropin stimulation in controlled ovarian stimulation cycles combined with intrauterine insemination therapy

Background: Infertility is commonly defined as the failure of conception after at least twelve months of unprotected intercourse. Factors contributing are both male and female in which unexplained etiology accounts for 51%, male factor 28%, endometriosis 17% and ovulatory disorders 4%.Methods: Prospective, randomized study was conducted at DRRPG medical college, Tanda, Kangra, Himachal Pradesh. In our study, patients were randomized into two groups of 30 each. Women in group A received clomiphene citrate 100mg/day and group B received letrozole 2.5 mg/day from day 3-7 of menstrual cycle. All the patients received human menopausal gonadotropin 75 U given every alternate day from day 5 until HCG administration. Ovulation was triggered with recombinant HCG (5000 IUIM) when the dominant follicles reached 18 mm in diameter. A single IUI was performed 36 hours later. A maximum of four cycles were given.Results: In our study, total number of induction cycles given in group A and B were 120 and 114 respectively. Out of these, 112 and 111 IUI cycles were done in group A and B respectively. A pregnancy rate of 1.66% and 7.87% per IUI cycle was observed in group A and B respectively.Thus it is concluded that the pregnancy rates were significantly higher in letrozole group (30%) in comparison to clomiphene citrate group (6.66%).Conclusions: Aromatase inhibitor letrozole appears to constitute a good alternative to clomiphene citrate in patients with unexplained infertility undergoing gonadotropin-stimulated COS cycles combined with IUI therapy

Evaluation of difference in central corneal thickness between premenopausal and postmenopausal women

Background: Menopause is defined as permanent cessation of menses. By convention the diagnosis of menopause is not made until the individual has had 12 months of amenorrhoea. It is a physiological condition, and associated with changes in levels of sex hormones. Certain changes occur in the corneal tissue due to change in these hormones. The current study intended to study any change in central corneal thickness among women after menopause. CCT can cause false readings in IOP measurements and affect the diagnosis and monitoring of glaucoma. Methods: It is a prospective, cross sectional, observational, case control study conducted in Department of Ophthalmology, GMC, Jammu for a period of 6 months from October 2022 to March 2023. 54 eyes of 27 patients each for pre and postmenopausal women were taken. Central corneal thickness was measured using specular biomicroscopy. Results: The mean age of post-menopausal women was found to be 52±2 years and pre-menopausal women was found to be 48±3. The mean of group 1 was found to be 524±18.67 microns and the mean of group 2 was found to 558±20.83 microns Conclusions: The data presented in this study suggest that menopause cause decrease in central corneal thickness

Yarkovsky Drift Detections for 247 Near-Earth Asteroids

The Yarkovsky effect is a thermal process acting upon the orbits of small celestial bodies, which can cause these orbits to slowly expand or contract with time. The effect is subtle (da/dt ~ 10^-4 au/My for a 1 km diameter object) and is thus generally difficult to measure. We analyzed both optical and radar astrometry for 600 near-Earth asteroids (NEAs) for the purpose of detecting and quantifying the Yarkovsky effect. We present 247 NEAs with measured drift rates, which is the largest published set of Yarkovsky detections. This large sample size provides an opportunity to examine the Yarkovsky effect in a statistical manner. In particular, we describe two independent population-based tests that verify the measurement of Yarkovsky orbital drift. First, we provide observational confirmation for the Yarkovsky effect's theoretical size dependence of 1/D, where D is diameter. Second, we find that the observed ratio of negative to positive drift rates in our sample is 2.34, which, accounting for bias and sampling uncertainty, implies an actual ratio of $2.7^{+0.3}_{-0.7}$. This ratio has a vanishingly small probability of occurring due to chance or statistical noise. The observed ratio of retrograde to prograde rotators is two times lower than the ratio expected from numerical predictions from NEA population studies and traditional assumptions about the sense of rotation of NEAs originating from various main belt escape routes. We also examine the efficiency with which solar energy is converted into orbital energy and find a median efficiency in our sample of 12%. We interpret this efficiency in terms of NEA spin and thermal properties.Comment: 27 pages, 9 figures, published in the Astronomical Journal, 159, 92, 202