Abelian 2-form gauge theory: superfield formalism

We derive the off-shell nilpotent Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for {\it all} the fields of a free Abelian 2-form gauge theory by exploiting the geometrical superfield approach to BRST formalism. The above four (3 + 1)-dimensional (4D) theory is considered on a (4, 2)-dimensional supermanifold parameterized by the four even spacetime variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of odd Grassmannian variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 = 0, \theta \bar\theta + \bar\theta \theta = 0). One of the salient features of our present investigation is that the above nilpotent (anti-)BRST symmetry transformations turn out to be absolutely anticommuting due to the presence of a Curci-Ferrari (CF) type of restriction. The latter condition emerges due to the application of our present superfield formalism. The actual CF condition, as is well-known, is the hallmark of a 4D non-Abelian 1-form gauge theory. We demonstrate that our present 4D Abelian 2-form gauge theory imbibes some of the key signatures of the 4D non-Abelian 1-form gauge theory. We briefly comment on the generalization of our supperfield approach to the case of Abelian 3-form gauge theory in four (3 + 1)-dimensions of spacetime.Comment: LaTeX file, 23 pages, journal versio

Agroforestry practices for water quality and quantity benefits

N/

Truthmakers and necessary connections

In this paper I examine the objection to truthmaker theory, forcibly made by David Lewis and endorsed by many, that it violates the Humean denial of necessary connections between distinct existences. In Sect. 1 I present the argument that acceptance of truthmakers commits us to necessary connections. In Sect. 2 I examine Lewis' 'Things-qua-truthmakers' theory which attempts to give truthmakers without such a commitment, and find it wanting. In Sects. 3-5 I discuss various formulations of the denial of necessary connections and argue that each of them is either false or compatible with truthmaker theory. In Sect. 6 I show how the truthmaker theorist can resist the charge that they are committed to necessary exclusions between possible existents. I conclude that there is no good objection to truthmaker theory on the grounds that it violates the Humean dictum

Variation of quantum well infrared photodetectors parameter with an applied electric field

A model is presented for the performance of quantum well infrared photodetectors (QWIPs) utilizing intersubband electron transitions and tunneling injection electrons. The dark current and the responsivity are derived as functions of the QWIP parameters, including the number of the QWs and electric field dependent capture probability in an analytical form. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2789

Rigid Rotor as a Toy Model for Hodge Theory

We apply the superfield approach to the toy model of a rigid rotor and show the existence of the nilpotent and absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations, under which, the kinetic term and action remain invariant. Furthermore, we also derive the off-shell nilpotent and absolutely anticommuting (anti-) co-BRST symmetry transformations, under which, the gauge-fixing term and Lagrangian remain invariant. The anticommutator of the above nilpotent symmetry transformations leads to the derivation of a bosonic symmetry transformation, under which, the ghost terms and action remain invariant. Together, the above transformations (and their corresponding generators) respect an algebra that turns out to be a physical realization of the algebra obeyed by the de Rham cohomological operators of differential geometry. Thus, our present model is a toy model for the Hodge theory.Comment: LaTeX file, 22 page

Monitoring changes in precipitation and radiative energy using satellite data and climate models

Current changes in the tropical hydrological cycle, including water vapour and precipitation, are presented over the period 1979-2008 based on a diverse suite of observational datasets and atmosphere-only climate models. Models capture the observed variability in tropical moisture while reanalyses cannot. Observed variability in precipitation is highly dependent upon the satellite instruments employed and only cursory agreement with model simulations, primarily relating to the interannual variability associated with the El Niño Southern Oscillation. All datasets display a positive relationship between precipitation and surface temperature but with a large spread. The tendency for wet, ascending regions to become wetter at the expense of dry, descending regimes is in general reproduced. Finally, the frequency of extreme precipitation is shown to rise with warming in the observations and for the model ensemble mean but with large spread in the model simulations. The influence of the Earth’s radiative energy balance in relation to changes in the tropical water cycle are discusse

How to be a truthmaker maximalist

When there is truth, there must be some thing to account for that truth: some thing that couldn’t exist and the true proposition fail to be true. That is the truthmaker principle. True propositions are made true by entities in the mind-independently existing external world. The truthmaker principle seems attractive to many metaphysicians, but many have wanted to weaken it and accept not that every true proposition has a truthmaker but only that some important class of propositions require truthmakers. Let us, following Armstrong, call the claim that all true propositions, without exception, have a truthmaker, Truthmaker Maximalism. Why might one be tempted to the spirit of truthmaker theory but reject Truthmaker Maximalism? Well, you might deny that necessary truths need truthmakers, for one, and insist that only contingent truths have truthmakers. But I think it’s fair to say that the most common motivation for rejecting maximalism concerns negative truths. (Continues...

Consumer willingness to pay for poultry products from biosecure farms in Bali

This study explores consumer perceptions and willingness to pay for clean and safe poultry products, particularly chicken meat and eggs, in Bali. The study also analyses the correlation between factors associated with the consumer’s purchase decision. Four high-end markets in Denpasar were chosen and 80 respondents were randomly selected in order to explore these issues. Nine attributes were used to define clean and safe poultry products, while five variables were used to explore the correlation between consumer characteristics and their purchase decision. The results show that consumers have a good understanding of clean and safe poultry products. They are aware how the product should appear physically, and they are willing to spend up to an extra Rp.5,0001 for whole chicken and Rp.10,000/kg for eggs. From the five consumer characteristic variables tested, only age and income have strong correlation with consumer purchase decisions. This information is useful for poultry producers as they seek to produce the type of product required by the supermarket consumer.Food Consumption/Nutrition/Food Safety,

Phosphorylation of phosphoenolpyruvate carboxykinase in plants. Studies in plants with C4 photosynthesis and Crassulacean acid metabolism and in germinating seeds

We have previously shown that phosphoenolpyruvate carboxykinase (PEPCK) is phosphorylated in vivo in the cotyledons of darkened cucumber seedlings and that phosphorylation is reversed by light [Walker and Leegood (1995) FEBS Lett. 362, 70–74]. In this study the molecular mass of PEPCK was estimated in a range of gluconeogenic seedlings and in leaves of C4 plants and plants with Crassulacean acid metabolism (CAM). Phosphorylation of PEPCK was studied in these plants by feeding tissues with [32P]Pi and assessing phosphorylation by SDS/PAGE and autoradiography of either total proteins or of immunoprecipitated protein. In gluconeogenic seedlings and most CAM plants PEPCK had a molecular mass of 74 kDa, whereas in C4 grasses the molecular mass of PEPCK was always smaller and varied from 67–71 kDa. In all gluconeogenic seedlings and leaves of CAM plants PEPCK was phosphorylated, but it was not phosphorylated in all species of C4 grasses studied. In CAM plants, phosphorylation of PEPCK occurred at night and dephosphorylation occurred during the day. In C4 grasses phosphorylation occurred when leaves were darkened and the enzyme was dephosphorylated following illumination, but it was only phosphorylated in those plants with larger (71 kDa) molecular mass forms of PEPCK

Marginalised youth, violence and policing: a qualitative study in Recife, Brazil

Few studies have examined the relations between urban marginalised youth and the public security system in the northeast of Brazil. This article addresses this gap in the literature through an examination of youth perceptions of a security programme aimed at reducing violence. It also analyses the effects of this security program by interrogating the hegemonic discourses of state-actors in the region, namely, agents of the criminal justice system. The analysis draws on ethnographic data collected between 2012 and 2016 in Recife, the capital city of the state of Pernambuco in the northeast of Brazil. This approach permits an examination of the nature of new security interventions, and a comparison between two distinct narratives about this new securitisation agenda. One overarching narrative focuses on young people’s vulnerabilities, the other on claims of successful securitisation. An analysis of these narratives widens understandings of the effects and risks of security interventions, contributing to a debate about their impact on young people’s lives and society at large