On the origin of comets

Physico-chemical processes leading to the dynamic formation and physical evolution of comets are reviewed in relationship to the various theories that propose solar origins, protoplanetary origins, planetary origins and interstellar origins. Evidence points to the origins of comets by the growth and agglomeration of small particles from gas and dust at very low temperatures at undetermined regions in space

On the origin of the solar system

Origin of solar syste

Plasma universe

Traditionally the views on the cosmic environent have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasmas. Such a medium may also emit synchrotron radiation which is observable in the radio region. If a model of the universe is based on the plasma phenomena mentioned it is found that the plasma universe is drastically different from the traditional visual universe. Information about the plasma universe can also be obtained by extrapolation of laboratory experiments and magnetospheric in situ measurements of plasmas. This approach is possible because it is likely that the basic properties of plasmas are the same everywhere. In order to test the usefulness of the plasma universe model it is applied to cosmogony. Such an approach seems to be rather successful. For example, the complicated structure of the Saturnian C ring can be accounted for. It is possible to reconstruct certain phenomena 4 to 5 billions of years ago with an accuracy of better than 1%

Cosmogony as an extrapolation of magnetospheric research

A theory of the origin and evolution of the Solar System which considered electromagnetic forces and plasma effects is revised in light of information supplied by space research. In situ measurements in the magnetospheres and solar wind can be extrapolated outwards in space, to interstellar clouds, and backwards in time, to the formation of the solar system. The first extrapolation leads to a revision of cloud properties essential for the early phases in the formation of stars and solar nebulae. The latter extrapolation facilitates analysis of the cosmogonic processes by extrapolation of magnetospheric phenomena. Pioneer-Voyager observations of the Saturnian rings indicate that essential parts of their structure are fossils from cosmogonic times. By using detailed information from these space missions, it is possible to reconstruct events 4 to 5 billion years ago with an accuracy of a few percent

Evolution of the Solar System

The origin and evolution of the solar system are analyzed. Physical processes are first discussed, followed by experimental studies of plasma-solid reactions and chemical and mineralogical analyses of meteorites and lunar and terrestrial samples

Are Electric Currents Heating the Magnetic Chromosphere?

This paper presents an analysis of three-dimensional vector currents and temperatures observed in a sunspot from the photosphere to the chromosphere, spanning a range of heights of approximately 1500 km. With this unique dataset, based on novel spectro-polarimetric observations of the 850 nm spectral region, it is possible to conduct for the first time an empirical study of the relation between currents and chromospheric heating. It is shown that, while resistive current dissipation contributes to heat the sunspot chromosphere, it is not the dominant factor. The heating effect of current dissipation is more important in the penumbra of the sunspot, but even there it is still a relatively modest contribution.Comment: Submitted to the Astrophysical Journal Letter

Association of OSTA index with bone mineral density (BMD) and its comparison with calcaneal quantitative ultrasound for the prediction of low BMD in peri-menopausal Indian women

Background: Osteoporosis is characterized by low bone mineral density (BMD) and an increased risk of fractures with advancing age in postmenopausal women. BMD measurements with dual energy X-ray absorptiometry (DEXA) are costly and not widely available The Osteoporosis Self-Assessment Tool for Asians (OSTA) index is a simple tool based on age and body weight to predict low BMD and identify women at risk of osteoporosis. The objective was to study the association of OSTA index with BMD (T-score) and to validate OSTA index in comparison with calcaneal Quantitative Ultrasound (QUS) for the prediction of low BMD in peri-menopausal Indian women.Methods: This was a prospective, cross-sectional, descriptive study carried out in department of physiology of a tertiary care teaching hospital (Navi Mumbai). Seventy two peri-menopausal women between 40 to 55 years with no previous diagnosis of osteoporosis were included. Participants’ socio-demographic detail, anthropometric measurements, OSTA index and QUS-based BMD was recorded. Pearson’s correlation test was used. Sensitivity, specificity, positive and negative predictive value was calculated.Results: OSTA index did not correlate with BMD in the entire samples. On subgroup analysis, OSTA index significantly correlated in a positive direction with BMD (T-score) in women in the age group of 50-55 years. OSTA index had a sensitivity of 70 %, and specificity of 84.62 % at T-score cutoff value of < -1.Conclusions: OSTA index is a simple risk assessment tool that can be used to identify women with low BMD in the age group of 50-55 years.

A prospective study of management of subtrochanteric femur fracture using proximal femoral nail

Background: Proximal femur fractures present considerable challenge in management. They are due to high velocity trauma, with or without soft tissue injury and usually with a metaphyseal and diaphyseal involvement. The surgeon has to face many challenges like identifying the entry, reduction the fracture, and difficulty due to a narrow medullary canal and comminution. The present study was conducted to assess the utility and effectiveness of Proximal Femoral Nail for subtrochanteric fractures of femur.Methods: In this study a total of 30 patients with Sub trochanteric femur fracture admitted to MGM medical college and hospital from June 2015 to July 2017 were selected for treatment with proximal femur nail.Results: 30 patients were included in this study with subtrochanteric fractures of femur treated with Proximal femoral nail. Maximum 21(70%) of patients were below 61 yrs of age. Mean age was 47.9 years. There was 21 male and 9 females in the study.  There were 6 patients with local complications. Final result of our study, we had 26.7% excellent, 46.6% good, 20% fair and 6.7 % poor results according to Harris hip score.Conclusions: In our study, looking at the results we found that Proximal femoral Nail proves to be a good implant in management of subtrochanteric fractures of femur.  However, it is a small study to conclude anything definitely

A Radio Polarimetric Study of the Galactic Center Threads

Multi-frequency, polarimetric VLA observations of the non-thermal filaments (NTF's), G0.08+0.15, and G359.96+0.09, also known as the Northern and Southern Threads are presented at 20, 6, 3.6 and 2 cm, with high enough spatial resolution to be resolved for the first time at 6 and 3.6 cm. The 20 cm image reveals a wealth of new detail in the radio sources lying within the inner 60 pc of the Galaxy. The Southern Thread has a prominent split along its length, similar to splitting at the ends of previously studied NTF's. With resolutions as fine as 2'', the 3.6 and 6 cm images reveal a high degree of continuity and little substructure internal to the filament. The spectral index of the Northern Thread has been determined over a broad range of frequencies. Its flux density falls with frequency, alpha=-0.5 between 90 and 6 cm, and becomes much steeper (alpha=-2.0) between 6 and 2 cm. The spectral index does not vary significantly along the length of the Northern Thread, which implies either that the diffusion timescale for the emitting electrons is less than their synchrotron lifetime, or that the emitting electrons are reaccelerated continuously at multiple positions along the filament. Because of the lack of spectral index variation, we have not located the source of relativistic electrons. Polarization observations at 6 and 3.6 cm confirm the non-thermal nature of the emission from the Northern Thread. The fractional polarization in the Northern Thread reaches 70% in some regions, although the polarized emission is patchy. Large rotation measures (RM > 2000 rad/m2) have been observed with irregular variations across the filament.The intrinsic magnetic field in the Northern Thread is predominantly aligned along its long axis.Comment: 19 pages, incl. 24 figs; to appear in the Astrophysical Journa

Expanding horizons of anticoagulant therapy: Dabigatran etexilate a novel oral anticoagulant

Thrombo-embolic disease is a major challenging clinical problem associated with significant mortality and morbidity. Anticoagulation with the existing heparin products and vitamin K antagonist (VKA) anticoagulants are still the mainstay of management. However, due to the risk of bleeding and well-documented drawbacks, the quest for a novel oral anticoagulant has led to the clinical development of dabigatran etexilate. Dabigatran etexilate is a direct thrombin (IIa) inhibitor which has recently been approved in India for prevention of venous thromboembolic events (VTE) in patients who have undergone major orthopaedic (total knee or hip replacement) surgery and for prevention of stroke, systemic embolism and reduction of vascular mortality in adult patients with atrial fibrillation. Thus dabigatran etexilate is a promising alternative to the current heparin products and VKAs in patients who require long-term oral anticoagulation