Dynamics of Local Group Satellite Galaxies in the Era of Precision Astrometry

High-precision astrometric data from the {\em Hubble Space Telescope} (HST) and {\em Gaia} are revolutionizing our ability to study galaxies in the Local Group (LG) in unprecedented detail. Recent breakthroughs, such as high accuracy proper motion (PM) measurements for Andromeda (M31), Triangulum (M33), and many of the dwarf galaxies orbiting the Milky Way (MW) and M31 now make it possible to analyze the interaction histories between satellite galaxies and their hosts. In this dissertation, I explore how the combination of astrometric data with high-resolution cosmological simulations can be used to improve our classical understanding of the LG's dynamical history. Using PMs from HST and the \textit{Very Long Baseline Array} and independently measured PMs with \textit{Gaia}, I show that the most plausible orbital history for M31's most massive satellite galaxy, M33, is a first infall scenario where M33 enters M31's halo in the last 2-4 Gyr, arriving at its closest position relative to M31 today. I also demonstrate that this orbital history is consistent with those of M33 analogs in M31-mass systems in \textit{Illustris-1-Dark}. M33's new orbital history is contrary to its classical orbit (developed before M31's PM was measured) where M33 has a close ($<$ 100 kpc), recent ($<$ 3 Gyr) tidal interaction with M31, resulting in M33's curious morphology. If on first infall into M31's halo, M33 is expected to retain its infall mass and any associated satellite galaxies. Here, I quantify the predicted satellite galaxy population of M33 in a $\Lambda$CDM paradigm, which may provide an alternative explanation for M33's warped morphology and can be directly tested with existing observatories. In the remaining chapters, I develop innovative methods to statistically constrain the precise masses of the MW and M31 by comparing the kinematic and dynamical properties of their satellite galaxies to the properties of simulated analogs in \textit{Illustris-1-Dark}. I show that the orbital angular momenta of satellite galaxies is the most reliable estimator of host halo mass over time. Using the angular momenta of multiple satellites simultaneously narrows the current uncertainty in the MW’s mass by $\sim$25\%, showing promise for improved constraints on the mass of M31 and ultimately the LG

Machine Learning the Dark Matter Halo Mass of Milky Way-Like Systems

Despite the Milky Way's proximity to us, our knowledge of its dark matter halo is fairly limited, and there is still considerable uncertainty in its halo mass. Many past techniques have been limited by assumptions such as the Galaxy being in dynamical equilibrium as well as nearby galaxies being true satellites of the Galaxy, and/or the need to find large samples of Milky Way analogs in simulations.Here, we propose a new technique based on neural networks that obtains high precision ($<0.14$ dex mass uncertainty) without assuming halo dynamical equilibrium or that neighboring galaxies are all satellites, and which can use information from a wide variety of simulated halos (even those dissimilar to the Milky Way) to improve its performance. This method uses only observable information including satellite orbits, distances to nearby larger halos, and the maximum circular velocity of the largest satellite galaxy. In this paper, we demonstrate a proof-of-concept method on simulated dark matter halos; in future papers in this series, we will apply neural networks to estimate the masses of the Milky Way's and M31's dark matter halos, and we will train variations of these networks to estimate other halo properties including concentration, assembly history, and spin axis

Asymmetric Drift of Andromeda Analogs in the IllustrisTNG Simulation

We analyze the kinematics as a function of stellar age for Andromeda (M31) mass analogs from the IllustrisTNG cosmological simulation. We divide the star particles into four age groups: less than 1 Gyr, 1 to 5 Gyr, 5 to 10 Gyr, and greater 10 Gyr, and compare the kinematics of these groups to that of the neutral gas cells. We calculate rotation curves for the stellar and gaseous components of each analog from 2 kpc to 20 kpc from the center of mass. We find that the lag, or asymmetric drift (AD), between the gas rotation curve and the stellar rotation curve on average increases with stellar age. This finding is consistent with observational measurements of AD in the disk of the Andromeda galaxy. When the M31 analogs are separated into groups based on merger history, we find that there is a difference in the AD of the analogs that have had a 4:1 merger the last 4 Gyr, 8 Gyr, or 12 Gyr compared to analogs that have not experienced a 4:1 merger in the same time frame. The subset of analogs that have had a 4:1 merger within the last 4 Gyr are also similar to AD measurements of stars in the disk of M31, providing evidence that M31 may in fact have recently merged with a galaxy nearly one fourth of its mass. Further work using high resolution zoom in simulations is required to explore the contribution of internal heating to AD.Comment: 14 pages, 11 figures, accepted to MNRAS for publication July 20, 202

Debating desalination: Stakeholder participation and decision-making in southern California

As desalination gains rapid traction worldwide, it is instructive to investigate how various stakeholders debate this water supply infrastructure and how decision-making processes incorporate stakeholder input. This paper conducts a discourse analysis of public comments and official deliberations tied to the permitting of Poseidon Water’s proposed $1.4 billion seawater desalination facility in Huntington Beach, California, which state regulators ultimately denied in May 2022. The facility was the first and largest desalination project to undergo permitting since the state passed desalination-specific legislation in 2015. This paper analyses public hearings between 2020 and 2022 at two key permitting agencies to detail the main storylines that proponents and opponents of this desalination facility used to justify their positions for, or against, the facility. Seven key themes are identified within the storylines. The paper shows that discursive tactics can create temporary openings for desalination debates to be depoliticised or (re)politicised in ways that influence permitting decisions on the margins, but that the decisionmaking process remains largely rigid to stakeholder participation. The results have implications for understanding desalination-specific issue areas for stakeholders and motivating decision-making processes to be more collaborative and engaging with stakeholders on newer water policy issues

Nelumbo Nucifera (Lotus): A Review on Ethanobotany, Phytochemistry and Pharmacology

Nelumbo nucifera Gaertn (Nymphaeaceae), a perennial aquatic plant, has been used as a medicinal herb in China and India. It has been recorded in the most famous medicinal book in China for more than 400 years. Different part of plant (leaves, seeds, flower, and rhizome) can be used in traditional system of medicine. In traditional system of medicine, the different parts of plant is reported to possess beneficial effects as in for the treatment of pharyngopathy, pectoralgia, spermatorrhoea, leucoderma, smallpox, dysentery, cough, haematemesis, epistaxis, haemoptysis, haematuria, metrorrhagia, hyperlipidaemia, fever, cholera, hepatopathy and hyperdipsia. Following the traditional claims for the use of N.nucifera as cure of numerous diseases considerable efforts have been made by researchers to verify it’s utility through scientific pharmacological screenings. The pharmacological studies have shown that N.nucifera posseses various notable pharmacological activities like amti-ischemic, antioxidant, anticancer, antiviral, antiobesity, lipolytic, hypocholestemic, antipyretic, hepatoprotective, hypoglycaemic, antidiarrhoeal, antifungal, antibacterial, antiinflammatory and diuretic activities. A wide variety of phytoprinciples have been isolated from the plant. The present review is an effort to consolidate traditional, ethnobotanic, phytochemical and pharmacological information available on N.nucifera

Management Of Bilateral Temporomandibular Joint Ankylosis With Micrognathia And Obstructive Sleep Apnea Syndrome Using Interpositional Arthroplasty And Distraction Osteogenesis – A Case Report

Temporomandibular joint (TMJ) Ankylosis posses many problems like inability to open the mouth, poor oral hygiene, difficulty in eating proper food, unaesthetic appearance due to growth retardation and in severe cases difficulty in breathing specially during night depending on the time of occurance of injury. If the TMJ Ankylosis occurs the early stage of life it affects both the form and function of the patient. One of the most common treatments used to treat temporomandibular joint (TMJ) ankylosis is interpositional arthroplasty (IPA). When patients come with severe mandibular dysplasia either orthognathic surgery or distraction osteogenesis (DO) can be considered. Simultaneous IPA with DO has been used by many surgeons correct TMJ ankylosis associated with facial asymmetry/micrognathia as as it enables them to simultaneously reconstruct the neocondyle and correct facial malformations eliminating the need for second surgery. Here we have narrated a case of an young male patient suffering from bilateral TMJ Ankylosis with micrognathia treated by simultaneous IPA and DO and regular follow up was done. &nbsp; &nbsp

DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF IVERMECTIN AND CLORSULON IN IVERCAM INJECTION

A precise, simple, accurate and selective method was developed and validate for estimation of Ivermectin and Clorsulon in Ivercam injection, Reversed phase high performance liquid chromatographic (RP-HPLC) method was developed for routine quantification of Ivermectin and Clorsulon in laboratory prepared mixtures as well as in combined dosage form. Chromatographic separation was achieved on a BDS hypersil C18 (5μ, 250 x 4.6 mm) utilizing mobile phase of filtered and degassed mixture of 60 phosphate buffer (pH 5.5 adjusted with 1% O-phosphoric acid) and Methanol (60:40 v/v) at a flow rate of 1 mL/min with UV detection at 234 nm. The method has been validated for linearity, accuracy and precision. In RP-HPLC method, the calibration graphs were linear in the concentration range of 2.5-7.5 μg/ml for Ivermectin and 25-75 μg/ml for Clorsulon with percentage recoveries of 100.34 % and 99.76% for Ivermectin and Clorsulon respectively. Conclusion: The results obtained by RP-HPLC methods are rapid, accurate and precise. Therefore proposed method can be used for routine analysis of Clorsulon and Ivermectin in injection

The Large Magellanic Cloud's ∼30\sim30 Kiloparsec Bow Shock and its Impact on the Circumgalactic Medium

The interaction between the supersonic motion of the Large Magellanic Cloud (LMC) and the Circumgalactic Medium (CGM) is expected to result in a bow shock that leads the LMC's gaseous disk. In this letter, we use hydrodynamic simulations of the LMC's recent infall to predict the extent of this shock and its effect on the Milky Way's (MW) CGM. The simulations clearly predict the existence of an asymmetric shock with a present day stand-off radius of $\sim6.7$ kpc and a transverse diameter of $\sim30$ kpc. Over the past 500 Myr, $\sim8\%$ of the MW's CGM in the southern hemisphere should have interacted with the shock front. This interaction may have had the effect of smoothing over inhomogeneities and increasing mixing in the MW CGM. We find observational evidence of the existence of the bow shock in recent $H\alpha$ maps of the LMC, providing a potential explanation for the envelope of ionized gas surrounding the LMC. Furthermore, the interaction of the bow shock with the MW CGM may also explain observations of ionized gas surrounding the Magellanic Stream. Using recent orbital histories of MW satellites, we find that many satellites have likely interacted with the LMC shock. Additionally, the dwarf galaxy Ret2 is currently sitting inside the shock, which may impact the interpretation of reported gamma ray excess in Ret2. This work highlights bow shocks associated with infalling satellites are an under-explored, yet potentially very important dynamical mixing process in the circumgalactic and intracluster media.Comment: Submitted to ApJ Letters, 5 figures and 1 table. Comments welcome

Diagnosis and staging of lung carcinoma with CT scan and its histopathological correlation

Background: Lung cancer is the most common cancer worldwide. Hence, timely diagnosis and accurate staging of the carcinoma is critical for the treatment and prognosis. So, this study was performed to evaluate the role of CT scan in diagnosis and staging of lung cancer.Methods: This was a prospective and observational study carried out over one and half years at a tertiary care hospital. The patients found to have abnormalities on chest X-ray suggestive of carcinoma were included in the study. Pre and post contrast CT scans were performed. Individual patient biopsies were done for histopathological staging.Results: Most patients belonged to 41-50 years age group with male preponderance (81.33%). Habit of smoking was prevalent among the lung cancer patients. Almost all masses (92%) showed heterogeneous contrast enhancement on CT. Additionally, there were calcifications, cavitation, hilar enlargement, pleural invasion, mediastinal lymphadenopathy and contiguous bone involvement. Adenocarcinoma was the most common (46.66%) form of cancer followed by squamous cell carcinoma (42.66%). For histopathological diagnosis, majority of patients (73.33%) were diagnosed using CT guided biopsy. In the remaining patients, USG guided biopsy or fibreoptic bronchoscopy were performed. The most common lobe affected by bronchogenic carcinoma was right upper lobe. The most common site of metastasis was pleura (22.66%) followed by bone (17.33%). Majority of the patients (41.33%) presented with TNM stage IV.Conclusions: CT scan as a modality for detection and staging of bronchogenic carcinoma is superior to chest radiograph. CT guided FNAC has a high success rate in evaluation of lung carcinoma.