N=4 SYM on S^3 with Near Critical Chemical Potentials

We study the N = 4 theory at weak coupling, on a three sphere in the grand canonical ensemble with R symmetry chemical potentials. We focus attention on near critical values for the chemical potentials, above which the classical theory has no ground state. By computing a one loop effective potential for the light degrees of freedom in this regime, we show the existence of flat directions of complex dimension N, 2N and 3N for one, two and three critical chemical potentials respectively; these correspond to one half, one quarter and one-eighth BPS states becoming light respectively at the critical values. At small finite temperature we show that the chemical potentials can be continued beyond their classical limiting values to yield a deconfined metastable phase with lifetime diverging in the large N limit. Our low temperaure analysis complements the high temperature metastability found by Yamada and Yaffe. The resulting phase diagram at weak coupling bears a striking resemblance to the strong coupling phase diagram for charged AdS black holes. Our analysis also reveals subtle qualitative differences between the two regimes.Comment: 34 pages, 4 figure

Germin and germin-like proteins: evolution, structure, and function

Germin and germin-like proteins (GLPs) are encoded by a family of genes found in all plants. They are part of the cupin superfamily of biochemically diverse proteins, a superfamily that has a conserved tertiary structure, though with limited similarity in primary sequence. The subgroups of GLPs have different enzyme functions that include the two hydrogen peroxide-generating enzymes, oxalate oxidase (OxO) and superoxide dismutase. This review summarizes the sequence and structural details of GLPs and also discusses their evolutionary progression, particularly their amplification in gene number during the evolution of the land plants. In terms of function, the GLPs are known to be differentially expressed during specific periods of plant growth and development, a pattern of evolutionary subfunctionalization. They are also implicated in the response of plants to biotic (viruses, bacteria, mycorrhizae, fungi, insects, nematodes, and parasitic plants) and abiotic (salt, heat/cold, drought, nutrient, and metal) stress. Most detailed data come from studies of fungal pathogenesis in cereals. This involvement with the protection of plants from environmental stress of various types has led to numerous plant breeding studies that have found links between GLPs and QTLs for disease and stress resistance. In addition the OxO enzyme has considerable commercial significance, based principally on its use in the medical diagnosis of oxalate concentration in plasma and urine. Finally, this review provides information on the nutritional importance of these proteins in the human diet, as several members are known to be allergenic, a feature related to their thermal stability and evolutionary connection to the seed storage proteins, also members of the cupin superfamily

Introducing Information Systems Approach for Acquiring IT Competence Needed For Business Applications

This article reports the findings of Information Systems Approach (ISA) and commonly used Traditional Approach (TA) on the acquisition of IT (Information Technology) competence of undergraduate students taking an introductory IT course in a business college. The ISA begins with the conceptual understanding of business activities followed by the introduction of databases, spreadsheets and the word-processing in line with the IT applications in business activities. While the Traditional Approach (TA) begins with conceptual understanding of business activities like the ISA, but followed by IT modules in sequence of word-processing, spreadsheets and then databases. Several groups were randomly selected from the same pool of students and introduced ISA and the TA for the acquisition of IT competence. The results indicated that the ISA group is more effective in enhancing IT competence in comparison to the TA group

Reflecting Disaster Risk in Development Indicators

Disasters triggered by hazards, such as floods, earthquakes, droughts, and cyclones, pose significant impediments to sustainable development efforts in the most vulnerable and exposed countries. Mainstreaming disaster risk is hence seen as an important global agenda as reflected in the Sustainable Development Goals (SDGs) and the Sendai Framework for Disaster Risk Reduction (SFDRR) 2015–2030. Yet, conventional development indicators remain largely negligent of the potential setbacks that may be posed by disaster risk. This article discusses the need to reflect disaster risk in development indicators and proposes a concept disaster risk-adjusted human development index (RHDI) as an example. Globally available national-level datasets of disaster risk to public and private assets (including health, educational facilities, and private housing) is combined with an estimate of expenditure on health, education, and capital formation to construct an RHDI. The RHDI is then analyzed across various regions and HDI groups, and contrasted with other HDI variants including inequality-adjusted HDI (IHDI) and the gender-specific female HDI (FHDI) to identify groups of countries where transformational disaster risk reduction (DRR) approaches may be necessary

Phase Transitions of Orientifold Gauge Theories at Large N in Finite Volume

In this paper we consider the phase structure of ``orientifold'' gauge theories--obtained from unitary supersymmetric gauge theories by replacing adjoint Majorana fermions by Dirac fermions in the symmetric or anti-symmetric representations--in finite volume S^3 x S^1. If the radius of the S^3 is small the calculations can be performed at weak coupling for any value of the S^1 radius. We demonstrate that there is a confinement/de-confining type of phase transition even when the fermions have periodic (non-thermal) boundary conditions around S^1. At small radius of S^1, the theory is in a phase where charge conjugation and large non-periodic gauge transformation are spontaneously broken. But for large radius of S^1 the phase preseves these symmetries just as in the related supersymmetric theory.Comment: 12 page

Freely falling bodies in a standing-wave spacetime

We study the motion of free masses subject to the influence of standing gravitational waves in the polarized Gowdy cosmology with a three-torus topology. We show that antinodes attract freely falling particles and we trace the velocity memory effect.Comment: 23 pages, 8 figures; minor changes to match published versio

Covid-19 Re-infection vs Prolonged Viral Shedding

  Since December 2019, COVID 19 pandemic has devastated communities across the world. As number of patients recovered from COVID 19 continue to rise, question of acquired immunity versus chances of re-infection becomes critical to understand the future spread of infection. Here, we present a case of a patient previously recovered from COVID-19, develops new symptoms concerning for possible re-infection with positive reverse transcriptase-polymerase chain reaction (RT-PCR) after few months of initial infection. &nbsp