472 research outputs found
The role of maritime transport sector from the perspective of energy and gender: The case of South Pacific
This paper discusses sustainable use of energy from a feminist perspective and focuses on the role of maritime transport sector in terms of energy access for rural women as users of maritime transport. In many parts of the world, the priorities of energy use tend to be gendered. Women are often excluded from decision-making process of energy choice and access. In the South Pacific where adequate recycling facilities and markets are not easily accessible, wastes are a big concern for their environments. An emerging concept of \u27circular economy\u27 to closing the loop of product life-cycles poses a challenge but also an opportunity for many South Pacific communities. For example, some rural women entrepreneurs found a business chance in waste management to participate in circular economy. One of the biggest obstacles encountered by them was, however, an access to ships to transport collected recycling items (e.g., used batteries) to recycling facilities overseas. In this paper, we argue whether a gendered nature of maritime transport may be limiting their capacity to provide services to minority users like women and what would be the role of maritime transport sector to support women\u27s contribution to establishing a sustainable, energy efficient society. The paper concludes that a missing link between women\u27s economic participation and the maritime transport sector to enable sustainable development of the South Pacific region should be recognised as part of the energy and gender agenda as well as the unexplored field of research
Closed cosmologies with a perfect fluid and a scalar field
Closed, spatially homogeneous cosmological models with a perfect fluid and a
scalar field with exponential potential are investigated, using dynamical
systems methods. First, we consider the closed Friedmann-Robertson-Walker
models, discussing the global dynamics in detail. Next, we investigate
Kantowski-Sachs models, for which the future and past attractors are
determined. The global asymptotic behaviour of both the
Friedmann-Robertson-Walker and the Kantowski-Sachs models is that they either
expand from an initial singularity, reach a maximum expansion and thereafter
recollapse to a final singularity (for all values of the potential parameter
kappa), or else they expand forever towards a flat power-law inflationary
solution (when kappa^2<2). As an illustration of the intermediate dynamical
behaviour of the Kantowski-Sachs models, we examine the cases of no barotropic
fluid, and of a massless scalar field in detail. We also briefly discuss
Bianchi type IX models.Comment: 15 pages, 10 figure
Adenoid cystic carcinoma of the peripheral lung: a case report
Adenoid cystic carcinoma of the peripheral lung is a rare entity. We recently encountered a patient with adenoid cystic carcinoma. A 75-year-old woman showed a nodular lesion with 10 mm in diameter in the right upper lung field on chest radiography. The diagnosis was unclear, but lung cancer could not be ruled out. Thoracoscopic biopsy was performed, and intraoperative pathological diagnosis revealed the carcinoma of the lung. We enforced upper lobectomy and mediastinal lymph node dissection to the patient. Histopathological examination revealed adenoid cystic carcinoma with a characteristic cribriform structure. Immunohistochemical examination revealed that the tumor cells were positive for thyroid transcription factor 1 (TTF-1), this tumor was diagnosed primary ACC of the lung
Self-similar spherically symmetric cosmological models with a perfect fluid and a scalar field
Self-similar, spherically symmetric cosmological models with a perfect fluid
and a scalar field with an exponential potential are investigated. New
variables are defined which lead to a compact state space, and dynamical
systems methods are utilised to analyse the models. Due to the existence of
monotone functions global dynamical results can be deduced. In particular, all
of the future and past attractors for these models are obtained and the global
results are discussed. The essential physical results are that initially
expanding models always evolve away from a massless scalar field model with an
initial singularity and, depending on the parameters of the models, either
recollapse to a second singularity or expand forever towards a flat power-law
inflationary model. The special cases in which there is no barotropic fluid and
in which the scalar field is massless are considered in more detail in order to
illustrate the asymptotic results. Some phase portraits are presented and the
intermediate dynamics and hence the physical properties of the models are
discussed.Comment: 31 pages, 4 figure
Isotropization of Bianchi-Type Cosmological Solutions in Brans-Dicke Theory
The cosmic, general analitic solutions of the Brans--Dicke Theory for the
flat space of homogeneous and isotropic models containing perfect, barotropic,
fluids are seen to belong to a wider class of solutions --which includes
cosmological models with the open and the closed spaces of the
Friedmann--Robertson--Walker metric, as well as solutions for models with
homogeneous but anisotropic spaces corresponding to the Bianchi--Type metric
clasification-- when all these solutions are expressed in terms of reduced
variables. The existence of such a class lies in the fact that the scalar
field, , times a function of the mean scale factor or ``volume element'',
, which depends on time and on the barotropic index of the
equation of state used, can be written as a function of a ``cosmic time''
reduced in terms of another function of the mean scale factor depending itself
again on the barotropic index but independent of the metrics here employed.
This reduction procedure permites one to analyze if explicitly given
anisotropic cosmological solutions ``isotropize'' in the course of their time
evolution. For if so can happen, it could be claimed that there exists a
subclass of solutions that is stable under anisotropic perturbations.Comment: 15 pages, Late
Neural processing of criticism and positive comments from relatives in individuals with schizotypal personality traits
Objectives. High negative expressed emotion by family members towards schizophrenia patients increases the risk of subsequent relapse. The study aimed to determine whether individuals with high schizotypy (HS) and low schizotypy (LS) would differ in activation of brain areas involved in cognitive control when listening to relative criticism
Cosmology with exponential potentials
We examine in the context of general relativity the dynamics of a spatially
flat Robertson-Walker universe filled with a classical minimally coupled scalar
field \phi of exponential potential ~ e^{-\mu\phi} plus pressureless baryonic
matter. This system is reduced to a first-order ordinary differential equation,
providing direct evidence on the acceleration/deceleration properties of the
system. As a consequence, for positive potentials, passage into acceleration
not at late times is generically a feature of the system, even when the
late-times attractors are decelerating. Furthermore, the structure formation
bound, together with the constraints on the present values of \Omega_{m},
w_{\phi} provide, independently of initial conditions and other parameters,
necessary conditions on \mu. Special solutions are found to possess intervals
of acceleration. For the almost cosmological constant case w_{\phi} ~ -1, as
well as, for the generic late-times evolution, the general relation
\Omega_{\phi}(w_{\phi}) is obtained.Comment: RevTex4, 9 pages, 2 figures, References adde
Properties of cosmologies with dynamical pseudo Nambu-Goldstone bosons
We study observational constraints on cosmological models with a quintessence
field in the form of a dynamical pseudo Nambu-Goldstone boson. After reviewing
the properties of the solutions, from a dynamical systems phase space analysis,
we consider the constraints on parameter values imposed by luminosity distances
from the 60 Type Ia supernovae published by Perlmutter et al., and also from
gravitational lensing statistics of distant quasars. In the case of the Type Ia
supernovae we explicitly allow for the possibility of evolution of the peak
luminosities of the supernovae sources, using simple empirical models which
have been recently discussed in the literature. We find weak evidence to
suggest that the models with supernovae evolution fit the data better in the
context of the quintessence models in question. If source evolution is a
reality then the greatest challenge facing these models is the tension between
current value of the expansion age, H_0 t_0, and the fraction of the critical
energy density, Omega_{phi0}, corresponding to the scalar field. Nonetheless
there are ranges of the free parameters which fit all available cosmological
data.Comment: 22 pages, RevTeX, 13 figures, epsf. v3: References added, plus a few
sentences to clarify some small points; v4: Typos fixe
Reductive Evolution of the Mitochondrial Processing Peptidases of the Unicellular Parasites Trichomonas vaginalis and Giardia intestinalis
Mitochondrial processing peptidases are heterodimeric enzymes (α/βMPP) that play an essential role in mitochondrial biogenesis by recognizing and cleaving the targeting presequences of nuclear-encoded mitochondrial proteins. The two subunits are paralogues that probably evolved by duplication of a gene for a monomeric metallopeptidase from the endosymbiotic ancestor of mitochondria. Here, we characterize the MPP-like proteins from two important human parasites that contain highly reduced versions of mitochondria, the mitosomes of Giardia intestinalis and the hydrogenosomes of Trichomonas vaginalis. Our biochemical characterization of recombinant proteins showed that, contrary to a recent report, the Trichomonas processing peptidase functions efficiently as an α/β heterodimer. By contrast, and so far uniquely among eukaryotes, the Giardia processing peptidase functions as a monomer comprising a single βMPP-like catalytic subunit. The structure and surface charge distribution of the Giardia processing peptidase predicted from a 3-D protein model appear to have co-evolved with the properties of Giardia mitosomal targeting sequences, which, unlike classic mitochondrial targeting signals, are typically short and impoverished in positively charged residues. The majority of hydrogenosomal presequences resemble those of mitosomes, but longer, positively charged mitochondrial-type presequences were also identified, consistent with the retention of the Trichomonas αMPP-like subunit. Our computational and experimental/functional analyses reveal that the divergent processing peptidases of Giardia mitosomes and Trichomonas hydrogenosomes evolved from the same ancestral heterodimeric α/βMPP metallopeptidase as did the classic mitochondrial enzyme. The unique monomeric structure of the Giardia enzyme, and the co-evolving properties of the Giardia enzyme and substrate, provide a compelling example of the power of reductive evolution to shape parasite biology
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