1,294 research outputs found
Unveiling Palomar 2: The Most Obscure Globular Cluster in the Outer Halo
We present the first color-magnitude study for Palomar 2, a distant and
heavily obscured globular cluster near the Galactic anticenter. Our (V,V-I)
color-magnitude diagram (CMD), obtained with the UH8K camera at the CFHT,
reaches V(lim) = 24 and clearly shows the principal sequences of the cluster,
though with substantial overall foreground absorption and differential
reddening. The CMD morphology shows a well populated red horizontal branch with
a sparser extension to the blue, similar to clusters such as NGC 1261, 1851, or
6229 with metallicities near [Fe/H] = -1.3, placing it about 34 kpc
from the Galactic center. We use starcounts of the bright stars to measure the
core radius, half-mass radius, and central concentration of the cluster. Its
integrated luminosity is M_V = -7.9, making it clearly brighter and more
massive than most other clusters in the outer halo.Comment: 25 pages, aastex, with 8 postscript figures; accepted for publication
in AJ, September 1997. Also available by e-mail from
[email protected]. Please consult Harris directly for (big)
postscript files of Figures 1a,b (the images of the cluster
Inversion improves the recognition of facial expression in thatcherized images
The Thatcher illusion provides a compelling example of the face inversion effect. However, the marked effect of inversion in the Thatcher illusion contrasts to other studies that report only a small effect of inversion on the recognition of facial expressions. To address this discrepancy, we compared the effects of inversion and thatcherization on the recognition of facial expressions. We found that inversion of normal faces caused only a small reduction in the recognition of facial expressions. In contrast, local inversion of facial features in upright thatcherized faces resulted in a much larger reduction in the recognition of facial expressions. Paradoxically, inversion of thatcherized faces caused a relative increase in the recognition of facial expressions. Together, these results suggest that different processes explain the effects of inversion on the recognition of facial expressions and on the perception of the Thatcher illusion. The grotesque perception of thatcherized images is based on a more orientation-sensitive representation of the face. In contrast, the recognition of facial expression is dependent on a more orientation-insensitive representation. A similar pattern of results was evident when only the mouth or eye region was visible. These findings demonstrate that a key component of the Thatcher illusion is to be found in orientation-specific encoding of the features of the face
The tilt of mean sea level along the east coast of North America
The tilt of mean sea level along the North American east coast has been a subject of debate for many decades. Improvements in geoid and ocean circulation models, and GPS positioning of tide gauge benchmarks, provide an opportunity to produce new tilt estimates. Tilts estimated using tide gauge measurements referenced to high-resolution geoid models (the geodetic approach) and ocean circulation models (the ocean approach) are compared. The geodetic estimates are broadly similar, with tilts downward to the north through the Florida Straits and at Cape Hatteras. Estimates from the ocean approach show good agreement with the geodetic estimates, indicating a convergence of the two approaches and resolving the long standing debate as to the sign of the tilt. These tilts differ from those used by Yin and Goddard (2013) to support a link between changing ocean circulation and coastal sea level rise
Outstanding Educational Performance Awards: Highlighting High Achieving Arkansas Schools, 2010
So, in this Arkansas Education Report (AER) we aim to highlight excellent performance and give our congratulations. To that end, we are happy to highlight many high performing schools around the state in our now-annual AER entitled the Outstanding Educational Performance Awards
Proactive, Not Reactive: Evolving Elm Management in the Nation\u27s Capital
Washington D.C. is home to many historic elm corridors managed in close partnership between numerous urban forestry stakeholders. In recent years, the city\u27s elms have been used as part of streetscape revitalization initiatives due to their quick-growing nature. The use of a popular Ulmus americana cultivar, Princeton, has brought about notable challenges in urban tree management. From the nursery to the tree box and even ten years later, these elms have required consistent attention in order to adequately train the form to achieve a sustainable canopy while minimizing structural defects. Two such plantings are explored, both with hand-selected trees from the same stock and nursery. These serve to highlight the differences between traditional urban forestry plantings and those under constant and careful scrutiny
Spotlights on Success: Traits and Strategies of Five High-Growth Schools in Arkansas
Successful schools are those which best educate the students, regardless of background. They are not those with students who come in well-educated but show only slight improvement, nor are they schools which use the disadvantage as an excuse for continued low levels of achievement. Instead, successful schools are those which advance the learning of all their children beyond what is expected
An overview of the major phenomena of the localization of sound sources by normal-hearing, hearing-impaired, and aided listeners
Localizing a sound source requires the auditory system to determine its direction and its distance. In general, hearing-impaired listeners do less well in experiments measuring localization performance than normal-hearing listeners, and hearing aids often exacerbate matters. This article summarizes the major experimental effects in direction (and its underlying cues of interaural time differences and interaural level differences) and distance for normal-hearing, hearing-impaired, and aided listeners. Front/back errors and the importance of self-motion are noted. The influence of vision on the localization of real-world sounds is emphasized, such as through the ventriloquist effect or the intriguing link between spatial hearing and visual attention
Spatial Encoding Strategy Theory: The Relationship between Spatial Skill and STEM Achievement
Learners’ spatial skill is a reliable and significant predictor of achievement in STEM, including computing, education. Spatial skill is also malleable, meaning it can be improved through training. Most cognitive skill training improves performance on only a narrow set of similar tasks, but researchers have found ample evidence that spatial training can broadly improve STEM achievement. We do not yet know the cognitive mechanisms that make spatial skill training broadly transferable when other cognitive training is not, but understanding these mechanisms is important for developing training and instruction that consistently benefits learners, especially those starting with low spatial skill. This paper proposes the spatial encoding strategy (SpES) theory to explain the cognitive mechanisms connecting spatial skill and STEM achievement. To motivate SpES theory, the paper reviews research from STEM education, learning sciences, and psychology. SpES theory provides compelling post hoc explanations for the findings from this literature and aligns with neuroscience models about the functions of brain structures. The paper concludes with a plan for testing the theory’s validity and using it to inform future research and instruction. The paper focuses on implications for computing education, but the transferability of spatial skill to STEM performance makes the proposed theory relevant to many education communities
The Effects of Increasing Organic or Inorganic Zinc on Growth Performance and Carcass Characteristics of Finishing Pigs
A total of 3,390 pigs (PIC 337 × 1050; initially 63.2 lb), housed in three replicate barns, were used in this study to determine the influence of increasing organic or inorganic Zn sources on growth performance and carcass characteristics of finishing pigs. A total of 126 pens of pigs were allotted to 1 of 7 dietary treatments, with 24 to 27 pigs per pen and 14 to 17 replications per treatment. All diets contained a trace mineral premix that provided 55 ppm of Zn from ZnSO4. The seven experimental treatments were a control diet with no additional zinc included in the diet; the control diet with an additional 25, 50, or 75 ppm of Zn from a zinc AA complex (ZnAA; Availa®-Zn; Zinpro Corporation, Eden Prairie, MN); or the control diet with an additional 25, 50, or 75 ppm of zinc from ZnO. Diets were fed in meal form, for five dietary phases, and formulated to maintain a constant standardized ileal digestible Lys:NE ratio within phase.
Overall, a Zn × level interaction (quadratic; P \u3c 0.05) was observed for ADG as pigs fed increasing ZnO had similar ADG, while pigs fed added levels of 25 and 50 ppm ZnAA had decreased performance compared to those fed the highest level of ZnAA. A Zn source × level interaction (quadratic; P \u3c 0.05) was also observed for overall F/G. This was due to pigs fed diets with 25 or 50 ppm Zn from ZnAA having poorer F/G compared to pigs fed similar levels of ZnO. The interaction in ADG also led to a tendency (quadratic; P \u3c 0.10) for a Zn source × level interaction for final BW. No differences were observed for ADFI. For carcass characteristics, a Zn source × level interaction (P \u3c 0.05) was observed for HCW, as pigs fed diets with 25 or 50 ppm Zn from ZnAA had decreased HCW compared with those fed 75 ppm Zn from ZnAA, while increasing ZnO did not influence HCW. Loin depth and percentage lean tended to increase and then decrease (quadratic; P \u3c 0.10) as added ZnAA increased; however, a similar response was not observed for increasing added ZnO. These data suggest that in finishing pigs, supplemental ZnO did not impact growth performance, but low inclusion levels of ZnAA increased F/G and reduced final BW
Effects of Potential Detoxifying Agents on Growth Performance and Deoxynivalenol (DON) Urinary Balance Characteristics of Nursery Pigs Fed DON-Contaminated Wheat
Two experiments were conducted to evaluate the effects of detoxifying agents on the growth performance of nursery pigs fed diets contaminated with deoxynivalenol (DON). Naturally DON-contaminated wheat (6 ppm) replaced noncontaminated wheat in diets to achieve desired dietary DON concentrations. Basal ingredients were tested for mycotoxin and amino acid content prior to diet manufacturing. Diets were pelleted at 180ËšF with a 45-s conditioning time.
A total of 238 barrows and gilts (PIC 327 × 1050; initially 29.6 ± 5.6 lb and 42 d of age) were used in a 21-d growth study. Pens of pigs were allotted by BW to 1 of 5 treatments in a completely randomized design with a 2 × 2 + 1 factorial arrangement. The 5 experimental diets included the following components, 1) positive control (PC; \u3c0.5 mg/kg DON); 2) PC + 1.0% Product X (Nutriquest LLC, Mason City, IA); 3) negative control (NC; 4.0 mg/kg DON); 4) NC + 1.0% Product X; and 5) NC + 1.0% sodium metabisulfite (SMB; Samirian Chemicals, Campbell, CA). There were 6 or 7 replicate pens per treatment and 7 pigs per pen. Chemical analysis indicated a low level of fumonisin (\u3c1 ppm) was present but that all DON concentrations matched calculated values. Analyzed DON concentrations were decreased by 92% when pelleted with SMB. Overall (d 0 to 21), a DON × Product X interaction was observed for ADG (P \u3c 0.05) and ADFI (P \u3c 0.10). Adding Product X to PC diets had no effect on ADG or ADFI; however, when added to NC diets, ADG, and ADFI became worse. As anticipated, DON reduced (P \u3c 0.001) ADG, ADFI, and F/G by 24, 16, and 10%, respectively. Deoxynivalenol-associated reductions in ADG were most distinct (50%) during the initial period (0.42 vs. 0.84 lb from d 0 to 7). Adding SMB to NC diets improved (P \u3c 0.01) ADG, ADFI, and F/G compared to pigs fed the NC alone, and also improved (P \u3c 0.02) ADG and F/G compared to pigs fed PC diets.
A concurrent urinary balance experiment was conducted using diets 3 to 5 from Exp. 1 to evaluate Product X and SMB on DON urinary metabolism. A 10-d adaptation was followed by a 7-d collection using 24 barrows in a randomized complete block design. Pigs fed NC + SMB diet had greater urinary output (P \u3c 0.05) than pigs fed NC + Product X, with NC pigs intermediate. Daily DON excretion was lowest (P \u3c 0.05) in the NC + SMB pigs. However, as a percentage of daily DON intake, NC + SMB fed pigs excreted more DON than they consumed (164%), greater (P \u3c 0.001) than pigs fed the NC (59%) or NC + Product X (48%), and indicative of degradation of DON back to the parent DON molecule. Overall, Product X did not alleviate DON effects on growth nor did it reduce DON absorption and excretion. However, hydrothermally processing DON-contaminated diets with 1.0% SMB restored ADFI and improved F/G. Even so, the urinary balance experiment revealed that some of the converted DON-sulfonate could degrade back to DON under physiological conditions. While SMB appears promising to restore performance in pelleted DON-contaminated diets, additional research needs to address handling and long-term supplementation concerns and to evaluate the stability of the DON-sulfonate conversion
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