1,273 research outputs found
Introduction: Ideologies of Youth
In a number of countries in Africa, such as Uganda and Kenya, national publics have been discussing whether citizens of age 50 or even 60 should be regarded as ‘youth’. Under the current dispensation of donor funding, relief programmes and international aid, these discussions have made the ‘youth’ the major beneficiary of what these policies offer and imply. There is a general feeling, however, that these policies should target all age groups in their youth-oriented programmes. If the donorideology prescribes youthfulness for societal and developmental relevance, it will then dictate practice. This is just one example of what this special issue will address in an attempt to explore what we see as an emerging development in Africa and beyond: the rise of youth as an ideology. Whereas Africa has witnessed the rise of a fast-growing study of youth as a phenomenon and as a concept, the aspect of youth as ideology has, so far, not been elaborated on
Superform formulation for vector-tensor multiplets in conformal supergravity
The recent papers arXiv:1110.0971 and arXiv:1201.5431 have provided a
superfield description for vector-tensor multiplets and their Chern-Simons
couplings in 4D N = 2 conformal supergravity. Here we develop a superform
formulation for these theories. Furthermore an alternative means of gauging the
central charge is given, making use of a deformed vector multiplet, which may
be thought of as a variant vector-tensor multiplet. Its Chern-Simons couplings
to additional vector multiplets are also constructed. This multiplet together
with its Chern-Simons couplings are new results not considered by de Wit et al.
in hep-th/9710212.Comment: 28 pages. V2: Typos corrected and references updated; V3: References
updated and typo correcte
The linear multiplet and ectoplasm
In the framework of the superconformal tensor calculus for 4D N=2
supergravity, locally supersymmetric actions are often constructed using the
linear multiplet. We provide a superform formulation for the linear multiplet
and derive the corresponding action functional using the ectoplasm method (also
known as the superform approach to the construction of supersymmetric
invariants). We propose a new locally supersymmetric action which makes use of
a deformed linear multiplet. The novel feature of this multiplet is that it
corresponds to the case of a gauged central charge using a one-form potential
not annihilated by the central charge (unlike the standard N=2 vector
multiplet). Such a gauge one-form can be chosen to describe a variant nonlinear
vector-tensor multiplet. As a byproduct of our construction, we also find a
variant realization of the tensor multiplet in supergravity where one of the
auxiliaries is replaced by the field strength of a gauge three-form.Comment: 31 pages; v3: minor corrections and typos fixed, version to appear in
JHE
Chemical Constituents of Snake Fruit (Salacca zalacca (Gaert.) Voss) Peel and in silico Anti-aging Analysis
Background: Skin aging is a condition where skin is unable to retain both its physiological and structural integrity. Plants is the main source of phtytochemicals compound with wide range of biological activities. Through the efforts of ongoing scientific researches, an increasing number of plant extracts and phytochemicals have been showed promising result as anti-aging agent. Snake fruit (Salacca zalacca (Gaert.) Voss) is tropical plant belongs to the palm tree family (Arecaceae) that served as important crop in Indonesia. Despite its utilization, the phytochemical compound available in snake fruit, especially its peel have not been well documented. Present study aimed to elucidate the phytochemical constituent of snake fruit peel and its anti-aging potency.Materials and Methods: Snake fruit peel extract (SPE) was subjected to qualitative phytochemical assay, high performance liquid chromatography, and molecular docking towards protein related in skin aging.Results: The screening showed SPE contained phytochemical compound belong to flavonoid, tannin, phenol, triterpenoid, saponin and alkaloid. Thus, based on the analysis only chlorogenic acid was present in SPE whilst rutin and caffeic acid were not detected. The SPE was contained chlorogenic acid around 1.074 mg/g dry weight. Chlorogenic acid had the high binding affinity towards matrix metalloproteinase (MMP)-1 (-9.4 kcal/mol).Conclusion: Current findings may provide scientific evidence for possible usage of SPE and its compounds as antioxidant and anti-aging agent.Keywords: Salacca zalacca, phytochemical compound, high performance liquid chromatography, anti-agin
Three form potential in (special) minimal supergravity superspace and supermembrane supercurrent
This contribution begins the study of the complete superfield Lagrangian
description of the interacting system of D=4 N=1 supergravity (SUGRA) and
supermembrane. Firstly, we review a 'three form supergravity' by Ovrut and
Waldram, which we prefer to call 'special minimal supergravity'. This off-shell
formulation of simple SUGRA is appropriate for our purposes as the
supermembrane action contains the so-called Wess-Zumino term given by the
integral over a three form potential in superspace, C3. We describe this
formulation in the frame of Wess--Zumino superfield approach, showing how the
basic variations of minimal SUGRA are restricted by the conditions of the
existence of a three-form potential C3 in its superspace. In this language the
effect of dynamical generation of cosmological constant, known to be
characteristic for this formulation of SUGRA, appears in its superfield form,
first described by Ogievetsky and Sokatchev in their formulation of SUGRA as a
theory of axial vector superfield. Secondly, we vary the supermembrane action
with respect to the special minimal SUGRA superfields (basic variations) and
obtain the supercurrent superfields as well as the supergravity superfield
equations with the supermembrane contributions.Comment: 18 pages, no figures. V2: Important references added. The abstract
and presentation have been changed to reflect the overloop with that.
Submitted to the QTS7 Proceedings. J. Phys. style use
Extended supersymmetric sigma models in AdS_4 from projective superspace
There exist two superspace approaches to describe N=2 supersymmetric
nonlinear sigma models in four-dimensional anti-de Sitter (AdS_4) space: (i) in
terms of N=1 AdS chiral superfields, as developed in arXiv:1105.3111 and
arXiv:1108.5290; and (ii) in terms of N=2 polar supermultiplets using the AdS
projective-superspace techniques developed in arXiv:0807.3368. The virtue of
the approach (i) is that it makes manifest the geometric properties of the N=2
supersymmetric sigma-models in AdS_4. The target space must be a non-compact
hyperkahler manifold endowed with a Killing vector field which generates an
SO(2) group of rotations on the two-sphere of complex structures. The power of
the approach (ii) is that it allows us, in principle, to generate hyperkahler
metrics as well as to address the problem of deformations of such metrics.
Here we show how to relate the formulation (ii) to (i) by integrating out an
infinite number of N=1 AdS auxiliary superfields and performing a superfield
duality transformation. We also develop a novel description of the most general
N=2 supersymmetric nonlinear sigma-model in AdS_4 in terms of chiral
superfields on three-dimensional N=2 flat superspace without central charge.
This superspace naturally originates from a conformally flat realization for
the four-dimensional N=2 AdS superspace that makes use of Poincare coordinates
for AdS_4. This novel formulation allows us to uncover several interesting
geometric results.Comment: 88 pages; v3: typos corrected, version published in JHE
Beyond Speculative Robot Ethics
In this article we develop a dialogue model for robot technology experts and designated users to discuss visions on the future of robotics in long-term care. Our vision assessment study aims for more distinguished and more informed visions on future robots. Surprisingly, our experiment also lead to some promising co-designed robot concepts in which jointly articulated moral guidelines are embedded. With our model we think to have designed an interesting response on a recent call for a less speculative ethics of technology by encouraging discussions about the quality of positive and negative visions on the future of robotics.
The Real Anatomy of Complex Linear Superfields
Recent work on classicication of off-shell representations of N-extended
worldline supersymmetry without central charges has uncovered an unexpectedly
vast number--trillions of even just (chromo)topology types--of so called
adinkraic supermultiplets. Herein, we show by explicit analysis that a
long-known but rarely used representation, the complex linear supermultiplet,
is not adinkraic, cannot be decomposed locally, but may be reduced by means of
a Wess-Zumino type gauge. This then indicates that the already unexpectedly
vast number of adinkraic off-shell supersymmetry representations is but the
proverbial tip of the iceberg.Comment: 21 pages, 4 figure
Supergravity for Effective Theories
Higher-derivative operators are central elements of any effective field
theory. In supersymmetric theories, these operators include terms with
derivatives in the K\"ahler potential. We develop a toolkit for coupling such
supersymmetric effective field theories to supergravity. We explain how to
write the action for minimal supergravity coupled to chiral superfields with
arbitrary numbers of derivatives and curvature couplings. We discuss two
examples in detail, showing how the component actions agree with the
expectations from the linearized description in terms of a Ferrara-Zumino
multiplet. In a companion paper, we apply the formalism to the effective theory
of inflation.Comment: 26 page
Purifying Selection in Deeply Conserved Human Enhancers Is More Consistent than in Coding Sequences
(c) 2014 De Silva et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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