Binary String Dynamics

In this paper we investigate the dynamical properties of binary cosmic strings. We find extrinsic curvature dependence of the string action and show that kinks on binary strings are eroded while cusps can play a major role in their evolution.Comment: 10 pages, plain TeX, uses harvmac and epsf, 1 postscript figur

A Comparative Study of a Class of Mean Field Theories of the Glass Transition

In a recently developed microscopic mean field theory, we have shown that the dynamics of a system, when described only in terms of its pair structure, can predict the correct dynamical transition temperature. Further, the theory predicted the difference in dynamics of two systems (the Lennard-Jones and the WCA) despite them having quite similar structures. This is in contrast to the Schweizer-Saltzman (SS) formalism which predicted the dynamics of these two systems to be similar. The two theories although similar in spirit have certain differences. Here we present a comparative study of these two formalisms to find the origin of the difference in their predictive power. We show that not only the dynamics in the potential energy surface, as described by our earlier study, but also that in the free energy surface, like in the SS theory, can predict the correct dynamical transition temperature. Even an approximate one component version of our theory, similar to the system used in the SS theory, can predict the transition temperature reasonably well. According to our analysis, the absence of the Vineyard approximation in the SS formalism led it to predict similar dynamics for the two systems. Interestingly, we show here that despite the above mentioned shortcomings the SS theory can actually predict the correct transition temperatures. Thus microscopic mean field theories of this class which express dynamics in terms of the pair structure of the liquid while being unable to predict the actual dynamics of the system are successful in predicting the correct dynamical transition temperature.Comment: 12 pages, 5 figure

The imaginary time Path Integral and non-time-reversal-invariant- saddle points of the Euclidean Action

We discuss new bounce-like (but non-time-reversal-invariant-) solutions to Euclidean equations of motion, which we dub boomerons. In the Euclidean path integral approach to quantum theories, boomerons make an imaginary contribution to the vacuum energy. The fake vacuum instabilty can be removed by cancelling boomeron contributions against contributions from time reversed boomerons (anti-boomerons). The cancellation rests on a sign choice whose significance is not completely understood in the path integral method.Comment: 19 pages, LaTex, 5 epsf figures. A new example from quantum mechanics is included. The role of internal symmetries is discussed. To be published in Nucl. Phys.

Improved Mass Constraints in the MSSM from Vacuum Stability

Using a simple numerical method, we compute the stability of the MSSM vacuum with respect to tunneling. The stability criterion is then used to put restrictions on the mass parameters. These restrictions are necessary conditions for the vacuum stability and compliment the existing sufficiency conditions obtained analytically.Comment: LaTex. 15 pages. 4 postscript figures (uses epsf). Some minor corrections. Enlarged data set. Figures showing data have been improve

Classification, reduction and stability of toric principal bundles

Let $X$ be a complex toric variety equipped with the action of an algebraic torus $T$, and let $G$ be a complex linear algebraic group. We classify all $T$-equivariant principal $G$-bundles $\mathcal{E}$ over $X$ and the morphisms between them. When $G$ is connected and reductive, we characterize the equivariant automorphism group $\text{Aut}_T(\mathcal{E} )$ of $\mathcal{E}$ as the intersection of certain parabolic subgroups of $G$ that arise naturally from the $T$-action on $\mathcal{E}$. We then give a criterion for the equivariant reduction of the structure group of $\mathcal{E}$ to a Levi subgroup of $G$ in terms of $\text{Aut}_T(\mathcal{E} )$. We use it to prove a principal bundle analogue of Kaneyama's theorem on equivariant splitting of torus equivariant vector bundles of small rank over a projective space. When $X$ is projective and $G$ is connected and reductive, we show that the notions of stability and equivariant stability are equivalent for any $T$-equivariant principal $G$-bundle over $X$.Comment: 47 page

Regeneration and Agrobacterium-mediated transformation of a popular indica rice variety, ADT39

A simple and efficient protocol for the regeneration and Agrobacterium-mediated transformation of an agronomically useful indica rice variety, ADT39 has been standardized. Initiation of callusing and its subculture were best achieved in MS medium supplemented with 300 mg/l casein enzymatic hydrolysate. The best callusing and regeneration responses were observed at concentrations of 2 mg/l 2,4-D and 1.5 mg/l BAP. Optimal transformation efficiency of 22.2% was obtained using high concentrations of augmentin as a bacteriostatic agent for a short period to inhibit the growth/ persistence of Agrobacterium, without compromising the regeneration potential of the tissue. Using a viral promoter-driven GUS reporter gene, morphologically normal fertile plants were obtained. Molecular analysis of the above transgenic plants indicated several independent, single-copy transgene insertion events. Expression of the reporter gene was detected in the above plants. Mendelian inheritance of the transgene in the progeny was also observed

Dual role of nanoparticles as drug carrier and drug.

The conventional chemotherapeutic agents used in the treatment of human malignancies are directed nonspecifically against both malignant and nonmalignant cells, often limiting their efficacy with having serious side effects. Recent development of drug delivery vehicles has opened up the possibility of targeted drug delivery systems with the potential of achieving maximum efficacy with minimal toxicity. The possibility of using a nanomaterial as a combinational drug component is intuitively evident as it would compensate the toxicity level by enhancing drug delivery efficiency. Additionally, cell-specific cytotoxicity (reported earlier by our group) of the nanovehicle itself may potentiate a more effective targeted cell killing. In this paper, we explore the possibility of using gold nanoparticles playing the dual role of an anticancer agent and a carrier of a chemotherapeutic drug. This is demonstrated using vincristine sulfate (VS), salt of an alkaloid often used in the treatment of multiple myeloma (MM), and U266 as a test MM cell line. The drug VS shows the expected G2-M-phase arrest of cells. Notably, bare gold nanoparticle shows arrest of the S phase cells that may be particularly important in case of slow-growing malignancies like MM where most of the cells remain in G1 phase of the cell cycle. The VS conjugated gold retains the activity of both gold nanoparticle and VS leading to a synergistic rise of the apoptotic cell population

Do we practice what we preach? Dialysis modality choice among healthcare workers in the United Kingdom

Background: In the United Kingdom, over 80% of end‐stage kidney disease patients receive in‐center hemodialysis. We conducted a survey of UK renal healthcare workers on their preferred dialysis modality if they needed dialysis themselves. Methods: An anonymized online survey was disseminated to all renal healthcare workers in the United Kingdom. We asked “Assume you are an otherwise well 40‐year‐old (and, separately, 75‐year‐old) person approaching end stage kidney disease, you have no living kidney donor options at present. There are no contraindications to any dialysis options. Which dialysis therapy would you choose?” We also asked about factors influencing their choice. Results: 858 individuals with a median age of 44.3 years responded. 70.2% were female, 37.4% doctors, and 31.1% were senior nurses. There was a preference for peritoneal dialysis over in‐center hemodialysis (50.47% v. 6.18%; p < 0.001 for 40‐year‐old and 49.18% v. 17.83%; p < 0.001 for 75‐year‐old assumption) and home hemodialysis (50.47% v. 39.28%; p < 0.001 for 40‐year‐old and 49.18% v. 18.41% for 75‐year‐old assumption). There was a preference for home hemodialysis over in‐center hemodialysis for 40‐year‐old (39.28% v. 6.18%; p < 0.001) but not for 75‐year‐old. On logistic regression, senior doctors were more likely to opt for PD when compared to nurses. Nurses, allied healthcare professionals, and those of Asian/British Asian ethnicity were more likely to choose in‐center hemodialysis. Conclusions: Most healthcare workers in renal medicine would choose home‐based treatment for themselves although the majority of end‐stage kidney disease patients receive in‐center hemodialysis in the United Kingdom; the reasons for the discrepancy need to be explored