10,044 research outputs found
Non-rationality of some fibrations associated to Klein surfaces
We study the polynomial fibration induced by the equation of the Klein
surfaces obtained as quotient of finite linear groups of automorphisms of the
plane; this surfaces are of type A, D, E, corresponding to their singularities.
The generic fibre of the polynomial fibration is a surface defined over the
function field of the line. We proved that it is not rational in cases D, E,
although it is obviously rational in the case A.
The group of automorphisms of the Klein surfaces is also described, and is
linear and of finite dimension in cases D, E; this result being obviously false
in case A.Comment: 18 page
Characterizing spiral arm and interarm star formation
Interarm star formation contributes significantly to a galaxy's star
formation budget, and provides an opportunity to study stellar birthplaces
unperturbed by spiral arm dynamics. Using optical integral field spectroscopy
of the nearby galaxy NGC 628 with VLT/MUSE, we construct Halpha maps including
detailed corrections for dust extinction and stellar absorption to identify 391
HII regions at 35pc resolution over 12 kpc^2. Using tracers sensitive to the
underlying gravitational potential, we associate HII regions with either arm
(271) or interarm (120) environments. Using our full spectral coverage of each
region, we find that most HII region physical properties (luminosity, size,
metallicity, ionization parameter) are independent of environment. We calculate
the fraction of Halpha luminosity due to the diffuse ionized gas (DIG)
background contaminating each HII region, and find the DIG surface brightness
to be higher within HII regions compared to the surroundings, and slightly
higher within arm HII regions. Use of the temperature sensitive [SII]/Halpha
line ratio map instead of the Halpha surface brightness to identify HII region
boundaries does not change this result. Using the dust attenuation as a tracer
of the gas, we find depletion times consistent with previous work (2 x 10^9 yr)
with no differences between the arm and interarm, however this is very
sensitive to the DIG correction. Unlike molecular clouds, which can be
dynamically affected by the galactic environment, we see fairly consistent HII
region properties in both arm and interarm environments. This suggests either a
difference in arm star formation and feedback, or a decoupling of dense star
forming clumps from the more extended surrounding molecular gas.Comment: 10 pages, 4 figures, 1 table, accepted for publication in Ap
Separate ways: The Mass-Metallicity Relation does not strongly correlate with Star Formation Rate in SDSS-IV MaNGA galaxies
We present the integrated stellar mass-metallicity relation (MZR) for more
than 1700 galaxies included in the integral field area SDSS-IV MaNGA survey.
The spatially resolved data allow us to determine the metallicity at the same
physical scale (effective radius in arcsecs, ) using a
heterogeneous set of ten abundance calibrators. Besides scale factors, the
shape of the MZR is similar for all calibrators, consistent with those reported
previously using single-fiber and integral field spectroscopy. We compare the
residuals of this relation against the star formation rate (SFR) and specific
SFR (sSFR). We do not find a strong secondary relation of the MZR with either
SFR or the sSFR for any of the calibrators, in contrast with previous
single-fiber spectroscopic studies. Our results agree with an scenario in which
metal enrichment happens at local scales, with global outflows playing a
secondary role in shaping the chemistry of galaxies and cold-gas inflows
regulating the stellar formation.Comment: 10 pages, 9 Figures. Accepted for publication in Ap
Human resources for control of tuberculosis and HIV-associated tuberculosis.
The global targets for tuberculosis (TB) control were postponed from 2000 to 2005, but on current evidence a further postponement may be necessary. Of the constraints preventing these targets being met, the primary one appears to be the lack of adequately trained and qualified staff. This paper outlines: 1) the human resources and skills for global TB and human immunodeficiency virus (HIV) TB control, including the human resources for implementing the DOTS strategy, the additional human resources for implementing joint HIV-TB control strategies and what is known about human resource gaps at global level; 2) the attempts to quantify human resource gaps by focusing on a small country in sub-Saharan Africa, Malawi; and 3) the main constraints to human resources and their possible solutions, under six main headings: human resource planning; production of human resources; distribution of the work-force; motivation and staff retention; quality of existing staff; and the effect of HIV/AIDS. We recommend an urgent shift in thinking about the human resource paradigm, and exhort international policy makers and the donor community to make a concerted effort to bridge the current gaps by investing for real change
Suppressed antinodal coherence with a single d-wave superconducting gap leads to two energy scales in underdoped cuprates
Conventional superconductors are characterized by a single energy scale, the
superconducting gap, which is proportional to the critical temperature Tc . In
hole-doped high-Tc copper oxide superconductors, previous experiments have
established the existence of two distinct energy scales for doping levels below
the optimal one. The origin and significance of these two scales are largely
unexplained, although they have often been viewed as evidence for two gaps,
possibly of distinct physical origins. By measuring the temperature dependence
of the electronic Raman response of Bi2Sr2CaCu2O8+d (Bi-2212) and HgBa2CuO4+d
(Hg-1201) crystals with different doping levels, we establish that these two
scales are associated with coherent excitations of the superconducting state
which disappears at Tc. Using a simple model, we show that these two scales do
not require the existence of two gaps. Rather, a single d-wave superconducting
gap with a loss of Bogoliubov quasiparticle spectral weight in the antinodal
region is shown to reconcile spectroscopic and transport measurements.Comment: 3 figure
Vortex distribution in the Lowest Landau Level
We study the vortex distribution of the wave functions minimizing the Gross
Pitaevskii energy for a fast rotating condensate in the Lowest Landau Level
(LLL): we prove that the minimizer cannot have a finite number of zeroes thus
the lattice is infinite, but not uniform. This uses the explicit expression of
the projector onto the LLL. We also show that any slow varying envelope
function can be approximated in the LLL by distorting the lattice. This is used
in particular to approximate the inverted parabola and understand the role of
``invisible'' vortices: the distortion of the lattice is very small in the
Thomas Fermi region but quite large outside, where the "invisible" vortices
lie.Comment: 4 pages, 1 figur
Fixed Asset Accounting Software Evaluation: A Structured Methodology For The Mid-Market Firm
Packaged software evaluation represents a major decision for business. It involves a number of quantitative as well as qualitative attributes in choosing among system alternatives. This paper illustrates an evaluation methodology for accounting software selection, specifically a fixed asset system. The methodology incorporates three stages: 1) software screening; 2) detail package evaluation; and, 3) confirmation and design (also known as a test drive).  Initially, developing a short list through screening of accounting software determines whether an appropriate package exists and narrows the field of available fixed asset products for detailed consideration. The second stage determines which of the remaining fixed asset systems (the finalists) best meets the needs of the organization, from both functional and technical perspectives. The final stage, or phase, compares user requirements with the features of the selected fixed asset software by determining how these requirements will be satisfied by specific applications built using the fixed asset software.  The methodology also controls for the possibility that no fixed asset software product is suitable and that such a system must be constructed on a custom basis. No other reported evaluation and selection approach offers this device. A case example demonstrating the applicability of the suggested methodology is given for a mid-sized hospital organization representing the largest market segment for accounting software
Validation of ICD-9-CM coding algorithm for improved identification of hypoglycemia visits
<p>Abstract</p> <p>Background</p> <p>Accurate identification of hypoglycemia cases by <it>International Classification of Diseases, Ninth Revision, Clinical Modification </it>(ICD-9-CM) codes will help to describe epidemiology, monitor trends, and propose interventions for this important complication in patients with diabetes. Prior hypoglycemia studies utilized incomplete search strategies and may be methodologically flawed. We sought to validate a new ICD-9-CM coding algorithm for accurate identification of hypoglycemia visits.</p> <p>Methods</p> <p>This was a multicenter, retrospective cohort study using a structured medical record review at three academic emergency departments from July 1, 2005 to June 30, 2006. We prospectively derived a coding algorithm to identify hypoglycemia visits using ICD-9-CM codes (250.3, 250.8, 251.0, 251.1, 251.2, 270.3, 775.0, 775.6, and 962.3). We confirmed hypoglycemia cases by chart review identified by candidate ICD-9-CM codes during the study period. The case definition for hypoglycemia was documented blood glucose 3.9 mmol/l or emergency physician charted diagnosis of hypoglycemia. We evaluated individual components and calculated the positive predictive value.</p> <p>Results</p> <p>We reviewed 636 charts identified by the candidate ICD-9-CM codes and confirmed 436 (64%) cases of hypoglycemia by chart review. Diabetes with other specified manifestations (250.8), often excluded in prior hypoglycemia analyses, identified 83% of hypoglycemia visits, and unspecified hypoglycemia (251.2) identified 13% of hypoglycemia visits. The absence of any predetermined co-diagnosis codes improved the positive predictive value of code 250.8 from 62% to 92%, while excluding only 10 (2%) true hypoglycemia visits. Although prior analyses included only the first-listed ICD-9 code, more than one-quarter of identified hypoglycemia visits were outside this primary diagnosis field. Overall, the proposed algorithm had 89% positive predictive value (95% confidence interval, 86–92) for detecting hypoglycemia visits.</p> <p>Conclusion</p> <p>The proposed algorithm improves on prior strategies to identify hypoglycemia visits in administrative data sets and will enhance the ability to study the epidemiology and design interventions for this important complication of diabetes care.</p
BIM and Mixed Reality for the New Management of Storage Area
The fourth industrial revolution that has touched the last decades, has involved several sectors including the construction world. The digitization and automation of industrial processes has implemented the development of connection platforms that can communicate many information for different users such as Smart Glasses or immersive headset. Most of the time, innovation does not only concern the technological field, but involves the entire organizational and managerial sphere. Digitization allows new tools such as Building Information Modelling to expand its application scale, making it an excellent tool for integrating and sharing data with their own information management systems (MES). The aims of this contribution are reproducing a virtual warehouse through parametric digital modelling, to which all the management data have been associated; for example, the average stock, the rotation index, etc. Thanks to the export of the database extrapolated from its management system of the analyzed industry, it was possible to define the correct visualization of the virtual model, interrogating the real data coming from the real warehouse. Through Smart Glasses, the user of the area could allocate the products in the correct position and update in the cloud the information properties associated with the individual product and the entire department. The use of virtual platforms for the visualization and the sharing of the data, facilitate the optimization of the industrial processes
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