1,808 research outputs found
Temperature and Emission-Measure Profiles Along Long-Lived Solar Coronal Loops Observed with TRACE
We report an initial study of temperature and emission measure distributions
along four steady loops observed with the Transition Region and Coronal
Explorer (TRACE) at the limb of the Sun. The temperature diagnostic is the
filter ratio of the extreme-ultraviolet 171-angstrom and 195-angstrom
passbands. The emission measure diagnostic is the count rate in the
171-angstrom passband. We find essentially no temperature variation along the
loops. We compare the observed loop structure with theoretical isothermal and
nonisothermal static loop structure.Comment: 10 pages, 3 postscript figures (LaTeX, uses aaspp4.sty). Accepted by
ApJ Letter
A RECONCEPTUALIZATION OF SOCIAL STRUCTURE OF ACCUMULATION THEORY
This article puts forward a reconceptualization of the theory of a social structure
of accumulation (SSA). The thirty years of neoliberalism presenta problem for SSA
theory. According to current SSA theory, an SSA is an institutional configuration
that for a long period of time promotes rapid capital accumulation and economic growth.
Although neoliberalism is clearly a new and long-lasting institutional structure that
replaced the postwar SSA, growth in the neoliberal economy has been relatively sluggish.
This article offers a revised concept of an SSA, which makes it possible to explain
neoliberalism as an SSA. It argues that every SSA promotes profit-making but does
not necessarily bring accumulation that is rapid by some historical standard. It introduces
the concept of liberal and regulated SSAs and examines the features of both types
of SSA. It considers the implications of this revised SSA theory for understanding
the current capitalist economic crisis.
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Mucosal Melanomas of the Head and Neck: The Role of Postoperative Radiation Therapy
Objectives. Mucosal melanomas are rarer than their cutaneous counterparts and are associated with a poorer prognosis. We report the clinical outcomes of patients with mucosal melanomas of the head and neck region generally treated with definitive surgery followed by postoperative radiation therapy (RT). Methods. We reviewed the records of 17 patients treated at the University of Miami in 1990–2007. Patients generally received conventionally fractionated RT regimens to the postoperative bed. Elective nodal RT was not routinely delivered. Eight patients received adjuvant chemotherapy or immunotherapy. Results. Median followup was 35.2 months (range 5–225). As the first site of failure: 3 patients recurred locally, 2 regionally and 2 distantly. All 3 patients who recurred locally had not received RT. Of the 5 locoregional recurrences, 4 were salvaged successfully with multimodality therapy with no evidence of disease at last followup. Overall survival was 64.7% at 2 years and 51.5% at 5 years. Conclusions. Patients with mucosal melanoma of the head and neck are best treated with surgery to achieve negative margins, followed by postoperative RT to optimize local control. Elective nodal irradiation may not be indicated in all cases, as regional failures were not predominant. Distant metastases were fewer when compared to historical data, potentially due to advancements in adjuvant therapies as well as aggressive multi-modality salvage at time of failure
Transversality of Electromagnetic Waves in the Calculus-Based Introductory Physics Course
Introductory calculus-based physics textbooks state that electromagnetic
waves are transverse and list many of their properties, but most such textbooks
do not bring forth arguments why this is so. Both physical and theoretical
arguments are at a level appropriate for students of courses based on such
books, and could be readily used by instructors of such courses. Here, we
discuss two physical arguments (based on polarization experiments and on lack
of monopole electromagnetic radiation), and the full argument for the
transversality of (plane) electromagnetic waves based on the integral Maxwell
equations. We also show, at a level appropriate for the introductory course,
why the electric and magnetic fields in a wave are in phase and the relation of
their magnitudes.Comment: 10 pages, 6 figure
Financial and capital account liberalisation, financial development and economic development: a review of some recent contributions
This article presents a review of some recent contributions on the relation between global finance and economic development in emerging economies. It first, stresses the growing consensus among economists on the financial instability that financial and capital account liberalization can possibly cause in emerging economies. It then outlines and compares two alternative strategies to tame such instability. The comparison is between the “good-institutions need-to-come-first” approach put forward by some mainstream economists, and the request for a deeper reform of the existing monetary system advocated by heterodox economists
Holomorphic Anomalies in Topological Field Theories
We study the stringy genus one partition function of SCFT's. It is
shown how to compute this using an anomaly in decoupling of BRST trivial states
from the partition function. A particular limit of this partition function
yields the partition function of topological theory coupled to topological
gravity. As an application we compute the number of holomorphic elliptic curves
over certain Calabi-Yau manifolds including the quintic threefold. This may be
viewed as the first application of mirror symmetry at the string quantum level.Comment: 32 pages. Appendix by S.Kat
Improving IGM temperature constraints using wavelet analysis on high-redshift quasars
Large scale structure and cosmolog
Topological Field Theory and Rational Curves
We analyze the superstring propagating on a Calabi-Yau threefold. This theory
naturally leads to the consideration of Witten's topological non-linear
sigma-model and the structure of rational curves on the Calabi-Yau manifold. We
study in detail the case of the world-sheet of the string being mapped to a
multiple cover of an isolated rational curve and we show that a natural
compactification of the moduli space of such a multiple cover leads to a
formula in agreement with a conjecture by Candelas, de la Ossa, Green and
Parkes.Comment: 20 page
Perfluorochemical Liquid-Adenovirus Suspensions Enhance Gene Delivery to the Distal Lung
We compared lung delivery methods of recombinant adenovirus (rAd): (1) rAd suspended in saline, (2) rAd suspended in saline followed by a pulse-chase of a perfluorochemical (PFC) liquid mixture, and (3) a PFC-rAd suspension. Cell uptake, distribution, and temporal expression of rAd were examined using A549 cells, a murine model using luciferase bioluminescence, and histological analyses. Relative to saline, a 4X increase in transduction efficiency was observed in A549 cells exposed to PFC-rAd for 2–4 h. rAd transgene expression was improved in alveolar epithelial cells, and the level and distribution of luciferase expression when delivered in PFC-rAd suspensions consistently peaked at 24 h. These results demonstrate that PFC-rAd suspensions improve distribution and enhance rAd-mediated gene expression which has important implications in improving lung function by gene therapy
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