5,353 research outputs found
An Extinction Map and Color Magnitude Diagram for the Globular Cluster NGC 3201
Differential variations of up to mag on a scale of
arcminutes across NGC 3201 are presented in the form of an extinction map. This
map, created by calculating average values for stars in small
subregions of the field with respect to a fiducial region, greatly improves the
appearance of the CMD of the cluster. We describe how we implemented this
technique in detail with our data for NGC 3201. A comparison between our map
and that of the same region extracted from the COBE/DIRBE reddening maps
published by Schlegel, Finkbeiner, & Davis (1998) (SFD) displays larger-scale
similarities between the two maps as well as smaller-scale features which show
up in our map but not in the SFD map. Several methods of determining an
zeropoint to add to our differential extinction map are presented.
Isochrone fitting proved to be the most successful one, but it produces an
average for the cluster which is smaller than previously published
values by . Finally, our results seem to support the statement
by Arce & Goodman (1999) that the SFD maps overestimate the reddening in
regions of high extinction.Comment: 19 pages, 12 figures, 1 table, accepted for publication in AJ (March
2001). Full resolution version may be obtained at
http://www.astro.lsa.umich.edu/users/kaspar/html/ngc3201.pdf (PDF) and at
http://www.astro.lsa.umich.edu/users/kaspar/html/ngc3201.ps.gz (PS
The FDA De Novo medical device pathway, patents and anticompetition.
The Food and Drug Administration (“FDA”) has long been criticized—perhaps, unfairly—for failing to expeditiously approve groundbreaking medical devices. In the views of some, thishas contributed to stagnation in the advancement of the medical device market and depressed
competition among purveyors of new devices. The 21st Century Cures Act has been lauded for
attempting to tackle these problems by easing several pathways for regulatory allowance. But
some of the Agency’s recent guidances in the area may hinder competition by opening the gates
to an anticompetitive patent strategy, one where marketers of “De Novo” medical devices—
medical devices given their own “device type” category—can kettle follow-on applicants into
patent infringement litigation. Knowing this, marketers of medical devices may avoid the 21st
Century Cures Act’s expansion of the 510(k) pathway for “De Novo” device types, defeating one
of the principal purposes of the Act
Characterisation of Hanseniaspora Isolates with Potential Aroma-enhancing Properties in Muscat Wines
The sensorial characteristics of the wines produced with Muscat grapes are related to the level of terpene alcohols, so an improvement of such a level is expected as a result of hydrolytic processes conducted by Hanseniaspora. The aim of this work was to select and identify new strains for this purpose. In a second step, the strains were assayed to evaluate their oenological abilities. H. uvarum H107 and H. vineae G26 and P38 were proven to be good candidates to be used in commercial vinification processes to enhance wine properties. Wine inoculated with yeasts showed an increase in the level of aromatic compounds
Precision Astrometry, Galactic Mergers, Halo Substructure and Local Dark Matter
The concordance Cold Dark Matter model for the formation of structure in the
Universe, while remarkably successful at describing observations on large
scales, has a number of problems on galaxy scales. The Milky Way and its
satellite system provide a key laboratory for exploring dark matter (DM) in
this regime, but some of the most definitive tests of local DM await
microarcsecond astrometry, such as will be delivered by the Space
Interferometry Mission (SIM Planetquest). I discuss several tests of Galactic
DM enabled by future microarcsecond astrometry.Comment: 8 pages, 3 figures, Proceedings of IAU Symposium 248 "A Giant Step:
from Milli- to Micro-arcsecond Astrometr
Promoting Comprehension Strategies of Primary Grade Students Through Datacasting Materials for Distance Learning
Many online learners especially in resource-challenged schools struggled with learning gaps during the pandemic crisis. This study focuses on using cost effective datacasting learning materials for distance education that promote intermediate grade students’ self-regulation, reading and writing skills. Datacasting is the process of delivering computer (IP) data over a traditional television broadcast signal. Locally, where only some households have Internet access but many have television sets, datacasting affords greater learning opportunities. Guided by structure, interactivity, and the functional language teaching theory, this study used sequential explanatory design to explore the role of datacasting in a public elementary school in Cavite in the academic year 2021 to 2022. Analyses of students’ artifacts reveal that their levels ofautonomy are non-autonomous, semi-autonomous, and autonomous. Moreover, the data also show that when they navigated the materials, they used these types of comprehension strategies: preparational, organizational, elaboration, andmonitoring. Correlations between culminating writing activities and final writing scores were found, but are not statistically significant, which may be attributed to the pandemic-induced sample attrition. The results suggest a need to refine the learning materials following the multimedia principles of personalization and embodiment through judicious text choice and adaptation and task design. Pedagogical recommendations for the use of datacasting materials are also offered
On Kinematic Substructure in the Sextans Dwarf Spheroidal Galaxy
We present multifiber echelle radial velocity results for 551 stars in the
Sextans dwarf spheroidal galaxy and identify 294 stars as probable Sextans
members. The projected velocity dispersion profile of the binned data remains
flat to a maximum angular radius of . We introduce a nonparametric
technique for estimating the projected velocity dispersion surface, and use
this to search for kinematic substructure. Our data do not confirm previous
reports of a kinematically distinct stellar population at the Sextans center.
Instead we detect a region near the Sextans core radius that is kinematically
colder than the overall Sextans sample with 95% confidence.Comment: accepted for publication in ApJ Letters; 4 figures (2 color
More people, more food, worse water? a global review of water pollution from agriculture
Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration.
We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks
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