Chondroblastoma of bone in extremities. - A single centre study of 177 cases

Introduction Chondroblastoma is a rare benign bone tumour that usually occurs in children and young adults. They are cartilaginous tumours arising in the epiphysis or apophysis of a long bone. The tumour is classified as benign, although rare cases of pulmonary metastases have been reported. The aims of this study were to describe clinical, radiographic characteristics of chondroblastoma; to analyse the local recurrence rate and complications associated with surgery. Material and methods This retrospective study included 177 patients, who had been diagnosed with a chondroblastoma in extremity between 1990 and 2015. Results The most common site was proximal tibia 20%, followed by proximal humerus 19%, proximal femur 18%, distal femur 16% and foot 15%. One patient has died of the disease and one patient is alive after being operated for lung metastases. There was local recurrence in 25/177 (14%) patients. The median time to local recurrence was 10 months (range 3-158 months). The most common site for local recurrence was proximal tibia (22.2%). The proximal femur was the location in 32/178 (18%) of the cases. 18/32 (56%) were in the greater trochanter and 14/32 (44%) in the femoral head. The mean age was lower in tumours located in femoral head when compared to the greater trochanter; 19.5 years and 13.9 years respectively (p=0.004). Tumours located in greater trochanter were all curetted without further complications. Local recurrence was seen more often in femoral head tumours, though without statistical significance; 3/14 (21%) and none, respectively (p=0.073). Conclusions Chondroblastoma is a rare benign to intermediate grade bone tumour with a potential to metastasise. Femoral head chondroblastoma is rare, presenting 4.5% of all chondroblastoma cases. Around 50% of the chondroblastoma in femoral head. occur in patients with open growth plates.Peer reviewe

Genetic variability studies in forage type hybrid parents of pearl millet

One hundred and sixteen forage-type hybrid parents of pearl millet were investigated in summer season for two years, the results revealed that the traits like number of tillers and leaf to stem ratio (L/S) at first cut (50 days after planting); and dry forage yield (DFY) at second cut (30 days after first cut) had high phenotypic coefficient of variation (PCV) values than genotypic coefficient of variation (GCV), hence selection will not be effective for these traits. Many of the desirable and undesirable forage quantity and quality linked traits under investigation had GCV almost equivalent to PCV, thus selection to improve those traits might be effective. High to moderate heritability coupled with high genetic advance per cent of mean (GA) was observed for plant height in both the cuts, indicating, this trait to be controlled by additive gene action and thus can be improved through selection, while, moderate heritability and high GA was observed for DFY at first cut; for green forage yield (GFY) at second cut and for total green forage yield (TGFY) from both the cuts, hence improvement in these traits will be possible through selection at later generations

Field Theories of Frustrated Heisenberg Antiferromagnets

We study the Heisenberg antiferromagnetic chain with both dimerization and frustration. The classical ground state has three phases: a Neel phase, a spiral phase and a colinear phase. In each phase, we discuss a non-linear sigma model field theory governing the low energy excitations. We study the theory in the spiral phase in detail using the renormalization group. The field theory, based on an $SO(3)$ matrix-valued field, becomes $SO(3) \times SO(3)$ and Lorentz invariant at long distances where the elementary excitation is analytically known to be a massive spin-$1/2$ doublet. The field theory supports $Z_2 ~$ solitons which lead to a double degeneracy in the spectrum for half-integer spins (when there is no dimerization).Comment: Latex, 12 pages, 2 figures (gzipped and uuencoded

Correlation and Path Coefficient Analysis of Biomass Yield and Quality Traits in Forage Type Hybrid Parents of Pearl Millet

One hundred and sixteen forage type hybrid parents (seed and pollinator parents) were investigated at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), India, in summer seasons of 2015 and 2016 for estimating inter-relationships between forage quantity and quality traits and their direct and indirect effects. Significant negative correlation but of low value was found between crude protein (CP), In vitro organic matter digestibility (IVOMD) and dry forage yield (DFY). The direct and indirect effect of these forage quantity related traits on the DFY and other forage quality related traits on IVOMD was investigated in pearl millet. Path analysis revealed that total green forage yield (TGFY) had highest positive direct effect on DFY for forage quantity traits followed by plant height (PH). For forage quality traits, metabolizable energy (ME) had highest direct effect on IVOMD in both the cuts. CP and cellulose also had positive direct effects on IVOMD in both the cuts

Transport in Double-Crossed Luttinger Liquids

We study transport through two Luttinger liquids (one-dimensional electrons interacting through a Coulomb repulsion in a metal) coupled together at {\it two} points. External voltage biases are incorporated through boundary conditions. We include density-density couplings as well as single-particle hops at the contacts. For weak repulsive interactions, transport through the wires remains undisturbed by the inter-wire couplings, which renormalise to zero. For strong repulsive interactions, the inter-wire couplings become strong. For symmetric barriers and no external voltage bias, a single gate voltage is sufficient to tune for resonance transmission in both wires. However, for asymmetric couplings or for finite external biases, the system is insulating.Comment: Latex file, 11 pages, one eps figur

Bosonic Mean Field Theory of the Spiral Phases of Heisenberg Antiferromagnets on a Chain

We develop a novel bosonic mean field theory to describe the spiral phases of a Heisenberg antiferromagnet on a one-dimensional chain, in terms of three bosons at each site. The ground state is disordered and for large values of the spin $S$, two different and exponentially small energy gaps are found. The spin-spin correlation function is computed and is shown to decay exponentially at large distances. Our mean field theory is also shown to be exact in a large-$N$ generalization.Comment: plain.tex, TIFR/TH/92-66, IISc/CTS/92-1

Junction of several weakly interacting quantum wires: a renormalization group study

We study the conductance of three or more semi-infinite wires which meet at a junction. The electrons in the wires are taken to interact weakly with each other through a short-range density-density interaction, and they encounter a general scattering matrix at the junction. We derive the renormalization group equations satisfied by the S-matrix, and we identify its fixed points and their stabilities. The conductance between any pair of wires is then studied as a function of physical parameters such as temperature. We discuss the possibility of observing the effects of junctions in present day experiments, such as the four-terminal conductance of a quantum wire and crossed quantum wires.Comment: RevTeX, 13 pages, including 4 eps figure

Analysis of COVID-19 pandemic - Origin, global impact and Indian therapeutic solutions for infectious diseases

103-117The first case of COVID-19 was reported in China in December 2019(ref. 1) and almost 213 countries have reported around 5,350,000 COVID-19 cases all over the world, with the mortality rate up to 3.4% as of May 23,2020. On March 11, 2020, the WHO (World Health Organization) declared COVID-19 as a global pandemic. Moving towards from epidemic to global pandemic situation just in two months, COVID-19 has caused tremendous adverse effects on people's well being and the economy all over the world. Scientists and researchers around the globe have a vested interest in researching and mitigating to handle the dire situation. This paper covers the COVID-19's origin, characteristics of the virus and reasons behind the outbreak, and precautionary measures that have to be followed to handle the critical situation. Several therapeutic solutions in the Indian healing tradition have been discussed to improve the immune system in order to equip ourselves to deal with the outbreak of COVID-19