The Hamiltonian Analysis for Yang-Mills Theory on R×S2R\times S^2

Pure Yang-Mills theory on ${\mathbb R} \times S^2$ is analyzed in a gauge-invariant Hamiltonian formalism. Using a suitable coordinatization for the sphere and a gauge-invariant matrix parametrization for the gauge potentials, we develop the Hamiltonian formalism in a manner that closely parallels previous analysis on ${\mathbb R}^3$. The volume measure on the physical configuration space of the gauge theory, the nonperturbative mass-gap and the leading term of the vacuum wave functional are discussed using a point-splitting regularization. All the results carry over smoothly to known results on ${\mathbb R}^3$ in the limit in which the sphere is de-compactified to a plane

Supersymmetry and Mass Gap in 2+1 Dimensions: A Gauge Invariant Hamiltonian Analysis

A Hamiltonian formulation of Yang-Mills-Chern-Simons theories with $0\leq N\leq 4$ supersymmetry in terms of gauge-invariant variables is presented, generalizing earlier work on nonsupersymmetric gauge theories. Special attention is paid to the volume measure of integration (over the gauge orbit space of the fields) which occurs in the inner product for the wave functions and arguments relating it to the renormalization of the Chern-Simons level number and to mass-gaps in the spectrum of the Hamiltonians are presented. The expression for the integration measure is consistent with the absence of mass gap for theories with extended supersymmetry (in the absence of additional matter hypermultiplets and/or Chern-Simons couplings), while for the minimally supersymmetric case, there is a mass-gap, the scale of which is set by a renormalized level number, in agreement with indications from existing literature. The realization of the supersymmetry algebra and the Hamiltonian in terms of the gauge invariant variables is also presented.Comment: 31 pages, References added, typos correcte

Bilateral Pleural Effusions due to Pulmonary Amyloidosis as the Presenting Manifestation of Multiple Myeloma

Multiple Myeloma is a hematologic malignancy of plasma cell origin. Pleural effusion may develop in the setting of myeloma due to various reasons but is extremely uncommon as a presenting symptom. A 69-year-old Caucasian man presented with pleural effusions of undetermined etiology after extensive work up, and multiple failed pleurodesis. Lung biopsy revealed pulmonary amyloidosis and led to the diagnosis of multiple myeloma. Patient was started on chemotherapy but died within 6 weeks of his diagnosis due to multiorgan failure. Pulmonary amyloidosis should be suspected as a cause of intractable pleural effusions, even in patient who do not have evidence of lung involvement on imaging studies or typical features of multiple myeloma. Pleural effusions due to amyloidosis are often refractory to treatment, and a high index of suspicion is required for early diagnosis and treatment

Dynein catch bond as a mediator of codependent bidirectional cellular transport

Intracellular bidirectional transport of cargo on microtubule filaments is achieved by the collective action of oppositely directed dynein and kinesin motors. Experiments have found that in certain cases, inhibiting the activity of one type of motor results in an overall decline in the motility of the cellular cargo in both directions. This counter-intuitive observation, referred to as {\em paradox of codependence} is inconsistent with the existing paradigm of a mechanistic tug-of-war between oppositely directed motors. Unlike kinesin, dynein motors exhibit catchbonding, wherein the unbinding rates of these motors decrease with increasing force on them. Incorporating this catchbonding behavior of dynein in a theoretical model, we show that the functional divergence of the two motors species manifests itself as an internal regulatory mechanism, and leads to codependent transport behaviour in biologically relevant regimes. Using analytical methods and stochastic simulations, we analyse the processivity characteristics and probability distribution of run times and pause times of transported cellular cargoes. We show that catchbonding can drastically alter the transport characteristics and also provide a plausible resolution of the paradox of codependence.Comment: 14 pages, 13 figure

Severe Degloving Injury with Covid-19 Infection – Successful Outcome and Hard Lessons Learnt

 Here we share an interesting case of severe trauma with tissue loss to nearly half of the back and a lacerated perineum in a Covid-19 positive patient in septic shock. This article highlights our experiences and hard lessons learnt in successful management of this complicated injury. Managing severe trauma is a challenge especially with respiratory failure resulting from Covid-19 infection. The patient reported to the hospital during a very difficult period, when proper medical care was difficult as hospitals and wards were filled with Covid positive patients. Managing patients was difficult especially wearing personal protective equipment round the clock. It’s a challenge when an entire team of surgeon, anesthesiologist, nursing staff and paramedics, rose above their daily call of duty to save the patient for her children. It was a fight against time and an many unknown enemy over three months for the entire team. The challenge to save a middle-aged patient from the claws of death against all odds was really miraculous. It was highly rewarding to see the patient going back to the family with a smile

Arthroscopic anterior cruciate ligament reconstruction with semitendinosus graft versus peroneus longus tendon graft

Background: Arthroscopic anterior cruciate ligament (ACL) reconstruction can be performed using autograft from various sources namely, bone patellar tendon graft, hamstring tendons (semitendinosus, gracilis) or peroneus longus tendon.Methods: A prospective study of 30 patients who underwent arthroscopic ACL reconstruction using quadrupled semitendinosus tendon autograft and peroneus longus tendon autograft during the study period.Results: Statistically, there is very little comparable difference between semitendinosus and peroneus longus when used for arthroscopic ACL reconstruction. However, peroneus longus tendon shows superior results when used in patients with grade 3 medial collateral ligament (MCL) injury combined with ACL injury.Conclusions: Our study brings forth the superior efficacy and quality of the double stranded peroneus longus tendon especially in cases associated with complicated injuries involving the medial collateral ligament with a follow up date of about 2 years and as a healthy supplement to other choices of autografts and revision cases