49 research outputs found
EFFECT OF STORAGE TEMPERATURES ON THE QUALITY OF PINK PERCH SURIMI
ABSTRACT A detailed investigation on microbiological, biochemical and organoleptic quality changes in frozen surimi of pink perch (Nemipterus japonicus) stored at ambient (25±5°C), refrigerated (5±3 °C) and at frozen temperatures (-10±2 °C), was carried out. Bacterial count, trimethylamine and total volatile nitrogen values increased with storage time while, organoleptic score decreased. Nutrient contents and gel strength of surimi decreased while, moisture and whiteness increased with storage period. Results indicated that at ambient temperature, frozen surimi can be stored only for about 8 hrs, while at refrigerator temperature up to 5 days and at frozen temperature up to 60 days.   Keywords: Pink pearch, minced meat, surimi, frozen storage. Â
Self-gravitating elastic bodies
Extended objects in GR are often modelled using distributional solutions of
the Einstein equations with point-like sources, or as the limit of
infinitesimally small "test" objects. In this note, I will consider models of
finite self-gravitating extended objects, which make it possible to give a
rigorous treatment of the initial value problem for (finite) extended objects.Comment: 16 pages. Based on a talk given at the 2013 WE-Heraeus seminar on
"Equations of motion in relativistic gravity
Theory of Star Formation
We review current understanding of star formation, outlining an overall
theoretical framework and the observations that motivate it. A conception of
star formation has emerged in which turbulence plays a dual role, both creating
overdensities to initiate gravitational contraction or collapse, and countering
the effects of gravity in these overdense regions. The key dynamical processes
involved in star formation -- turbulence, magnetic fields, and self-gravity --
are highly nonlinear and multidimensional. Physical arguments are used to
identify and explain the features and scalings involved in star formation, and
results from numerical simulations are used to quantify these effects. We
divide star formation into large-scale and small-scale regimes and review each
in turn. Large scales range from galaxies to giant molecular clouds (GMCs) and
their substructures. Important problems include how GMCs form and evolve, what
determines the star formation rate (SFR), and what determines the initial mass
function (IMF). Small scales range from dense cores to the protostellar systems
they beget. We discuss formation of both low- and high-mass stars, including
ongoing accretion. The development of winds and outflows is increasingly well
understood, as are the mechanisms governing angular momentum transport in
disks. Although outstanding questions remain, the framework is now in place to
build a comprehensive theory of star formation that will be tested by the next
generation of telescopes.Comment: 120 pages, to appear in ARAA. No changes from v1 text; permission
statement adde
Interaction Between Convection and Pulsation
This article reviews our current understanding of modelling convection
dynamics in stars. Several semi-analytical time-dependent convection models
have been proposed for pulsating one-dimensional stellar structures with
different formulations for how the convective turbulent velocity field couples
with the global stellar oscillations. In this review we put emphasis on two,
widely used, time-dependent convection formulations for estimating pulsation
properties in one-dimensional stellar models. Applications to pulsating stars
are presented with results for oscillation properties, such as the effects of
convection dynamics on the oscillation frequencies, or the stability of
pulsation modes, in classical pulsators and in stars supporting solar-type
oscillations.Comment: Invited review article for Living Reviews in Solar Physics. 88 pages,
14 figure
Physics, Astrophysics and Cosmology with Gravitational Waves
Gravitational wave detectors are already operating at interesting sensitivity
levels, and they have an upgrade path that should result in secure detections
by 2014. We review the physics of gravitational waves, how they interact with
detectors (bars and interferometers), and how these detectors operate. We study
the most likely sources of gravitational waves and review the data analysis
methods that are used to extract their signals from detector noise. Then we
consider the consequences of gravitational wave detections and observations for
physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version
<http://www.livingreviews.org/lrr-2009-2
An Interactive Internet-Based Continuing Education Course on Sexually Transmitted Diseases for Physicians and Midwives in Peru
Clinicians in developing countries have had limited access to continuing education (CE) outside major cities, and CE strategies have had limited impact on sustainable change in performance. New educational tools could improve CE accessibility and effectiveness.The objective of this study was to evaluate an interactive Internet-based CE course on Sexually Transmitted Diseases (STDs) management for clinicians in Peru. Participants included physicians and midwives in private practice drawn from a census of 10 Peruvian cities. The CE included a three-hour workshop for improving Internet skills, followed by a 22-hour online course on STD-syndrome-management, with subsequent educational support. The course used case-based clinical vignettes tailored to local STD problems. Knowledge and reported practices on STD management were assessed before, immediately after and at four months after completion of the course. Statistical analysis included parametric tests-linear regression multivariate analysis, paired t-test and repeated measures ANOVA using SPSS 14.0. Of 1,071 eligible clinicians, 510 agreed to participate, as did an additional 132 public sector clinicians. Of these 642 participants, 619 (96.4%) completed the course, and 596 (96.3%) took the four-month follow-up evaluation. Physician and midwife scores improved from 64.2% correct answers on the pre-test to 77.9% correct on the four-month follow-up test (p<0.001). Most participants (95%) found the online course useful for their work needs. Self reported STD management practices did not change.Among physicians and midwives in Peru, an Internet-based CE course was feasible, acceptable with high participation rates, and led to sustained improvement in knowledge at four months. Further studies are needed to test it as a model for improving the training of physicians, midwives, and other health care providers
Asteroseismology and Interferometry
Asteroseismology provides us with a unique opportunity to improve our
understanding of stellar structure and evolution. Recent developments,
including the first systematic studies of solar-like pulsators, have boosted
the impact of this field of research within Astrophysics and have led to a
significant increase in the size of the research community. In the present
paper we start by reviewing the basic observational and theoretical properties
of classical and solar-like pulsators and present results from some of the most
recent and outstanding studies of these stars. We centre our review on those
classes of pulsators for which interferometric studies are expected to provide
a significant input. We discuss current limitations to asteroseismic studies,
including difficulties in mode identification and in the accurate determination
of global parameters of pulsating stars, and, after a brief review of those
aspects of interferometry that are most relevant in this context, anticipate
how interferometric observations may contribute to overcome these limitations.
Moreover, we present results of recent pilot studies of pulsating stars
involving both asteroseismic and interferometric constraints and look into the
future, summarizing ongoing efforts concerning the development of future
instruments and satellite missions which are expected to have an impact in this
field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume
14, Issue 3-4, pp. 217-36
Magnetic Response in the Holographic Insulator/Superconductor Transition
We study the magnetic response of holographic superconductors exhibiting an
insulating "normal" phase. These materials can be realized as a CFT
compactified on a circle, which is dual to the AdS Soliton geometry. We study
the response under i) magnetic fields and ii) a Wilson line on the circle.
Magnetic fields lead to formation of vortices and allows one to infer that the
superconductor is of type II. The response to a Wilson line is in the form of
Aharonov-Bohm-like effects. These are suppressed in the holographic
conductor/superconductor transition but, instead, they are unsuppressed for the
insulator case. Holography, thus, predicts that generically insulators display
stronger Aharonov-Bohm effects than conductors. In the fluid-mechanical limit
the AdS Soliton is interpreted as a supersolid. Our results imply that
supersolids display unsuppressed Aharonov-Bohm (or "Sagnac") effects - stronger
than in superfluids.Comment: 31 pages, 24 figures; discussion on vortex lattice, few comments and
references added; article published in JHE
QCD and strongly coupled gauge theories : challenges and perspectives
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe