1,624 research outputs found
Computers and Learning
The important questions for instructors to address concern what skills the student is to learn and how the student is to be motivated to acquire those skills. Questions about simulations, graphics tools, and the like are unimportant until the first two questions have been answered adequately. We discuss the role of explanation by students and describe a mechanism for motivating students to learn
Growth and survival of spat, juveniles and adult Akoya pearl oyster Pinctada imbricata fucata (Gould, 1850) in different rearing conditions and stocking densities
Growth trials were conducted using hatchery produced spat of Pinctada imbricata fucata (Gould, 1850) having average dorso-ventral measurement (DVM) of 3.99 mm, hinge length (HL) 3.94 mm, thickness (THK) 1.25 mm and weight (WGT) 0.008 g. The first experiment was a comparative growth assessment of spat grown in one ton FRP tanks in the hatchery and with that of spat reared in micron meshed cages under open sea conditions for a period of three months. During the third month, spats grown in micron meshed cages showed growth increments of 7.83 mm (DVM), 4.86 mm (HL), 1.61 mm (THK) and 0.192 g (WGT) whereas those grown in FRP tanks grew only by 0.95 mm (DVM), 0.5 mm (HL), 0.46 mm (THK) and 0.004 g (WGT) indicating faster growth in open sea conditions. Second experiment was conducted to elucidate the effect of stocking density on the growth and survival of juveniles reared in plastic baskets at different stocking densities viz., 200 (0.03 nos. cm-3) , 300 (0.049 nos. cm-3), 400 (0.065 nos. cm-3), 500 (0.08 nos. cm-3), 600 (0.098 nos. cm-3), 700 (0.11 nos.cm-3), 800 (0.13 nos. cm-3), 900 (0.14 nos. cm-3) and 1000 (0.16 nos. cm-3) numbers per basket. Results indicated that P. imbricata fucata juveniles can be grown at stocking densities of upto 400 nos per basket for a period of five months with 90% survival without much reduction in growth. Third experiment was conducted on the growth of P. imbricata fucata subadults in box cages at different stocking densities viz., 200 (0.006 nos. cm-3), 300 (0.01 nos. cm-3), 400 (0.013 nos. cm-3),
500 (0.016 nos. cm-3), 600 (0.02 nos. cm-3), 700 (0.023 nos. cm-3), 800 (0.026 nos. cm-3), 900 (0.03 nos. cm-3) and 1000
(nos. cm-3) numbers per cage. Survival rates ranged from 98.5 to 98.6% at stocking densities up to 400 nos. per cage during the fifth month without any significant variation in the DVM, HL and THK of oysters
The Arcturus Moving Group: Its Place in the Galaxy
The Arcturus moving group is a well-populated example of phase space
substructure within the thick disk of our Galaxy. Traditionally regarded as the
remains of a dissolved open cluster, it has recently been suggested to be a
remnant of a satellite accreted by our Galaxy. To investigate the origin of the
group we undertook a high-resolution spectroscopic abundance study of Arcturus
group members and candidates. Examining abundance of Fe, Mg, Ca, Ti, Cr, Ni,
Zn, Ce, Nd, Sm and Gd for 134 stars we found that the group is chemically
similar to disk stars and does not exhibit a clear chemical homogeneity.
Furthermore, we confirm the existence of the Arcturus group using the
Nordstroem et al. (2004), Schuster et al. (2006) and RAdial Velocity Experiment
(RAVE) surveys (Steinmetz et al. 2006). The origin of the group still remains
unresolved: the chemical results are consistent with a dynamical origin but do
not entirely rule out a merger one. Certainly, the Arcturus group provides a
challenge to our understanding of the nature and origin of the Galaxy's thick
disk.Comment: 6 pages, 2 figures, to appear in the Proceedings of the IAU Symposium
254: The Galaxy Disk in Cosmological Contex
Psychometric Analysis of the Emotional Tone Rating Scale: A Measure of Person-Centered Communication
This is an Accepted Manuscript of an article published by Taylor & Francis in Clinical Gerontologist on 2012-01-01, available online: http://www.tandfonline.com/10.1080/07317115.2012.702648.Psychometric analysis of the Emotional Tone Rating Scale (ETRS) was completed using ratings of naïve listeners who evaluated staff-resident communication in three nursing homes. Interrater consistency was high with ICC (2, 1) for agreement = 0.95 and consistency = 0.95. Factor analysis revealed two factors—person-centered communication and controlling communication—that explained 84.8% of the variance. Person-centered communication included seven descriptors (items) with loadings ranging from 0.84 to 0.98 and a coefficient alpha of 0.98. Controlling communication included five items that loaded from −0.63 to .99 with a coefficient alpha of 0.94. These factors were negatively correlated p = −.64 and demonstrated good ranges, standard deviations, and high item-total correlations. Person-centered communication correlated with higher resident engagement in conversation in contrast to controlling communication. The ETRS provides a measure of person-centered communication that can be used to evaluate interactions between nursing staff and older adults who reside in long term care settings
Seasonal and positional variations in the rate of nacre coating in Indian pearl oyster Pinctada fucata (Gould, 1850)
Recently technology has been perfected for the production of quality
image pearls (mabe pearls) in India which fetches a good price ranging
from $20-50 per pearl. This study focused on variations in the rate of nacre
coating during different seasons when implanted with image pearl nucleus
in different positions of the pearl oyster shell. The implantation was done
at three positions at P1, P2 and P3 in both shells and the experiments were
repeated in three seasons namely pre monsoon, monsoon and post
monsoon. Among the positions, the position P2 which is the wide
marginal mantle region gave the maximum nacre coating rate. Hydrological
parameters such as atmospheric and water temperature, salinity, pH,
turbidity, ammonia, nitrite, nitrate, phosphate, silicate, dissolved oxygen,
primary productivity and chlorophyll a were also recorded during the
study. Rate of nacre coating was found to be maximum (6.79 ± 2.07 μ/
day) during post monsoon months corresponding to maximum productivity
(Net Primary Production of 204.40 ± 45.86 mgC/m3/day and Gross
Primary Production of 361.40 ± 96.92 mgC/m3/day) and chlorophyll
concentration (2.79 ± 0.13 mg/m³). The rate of coating was minimum
(2.19 ± 0.17 μ/day) during pre monsoon season. The influence of
hydrological parameters and positions of the implanted nuclei on the nacre
coating were statistically analysed and discussed in the present paper
New distances to RAVE stars
Probability density functions are determined from new stellar parameters for
the distance moduli of stars for which the RAdial Velocity Experiment (RAVE)
has obtained spectra with S/N>=10. Single-Gaussian fits to the pdf in distance
modulus suffice for roughly half the stars, with most of the other half having
satisfactory two-Gaussian representations. As expected, early-type stars rarely
require more than one Gaussian. The expectation value of distance is larger
than the distance implied by the expectation of distance modulus; the latter is
itself larger than the distance implied by the expectation value of the
parallax. Our parallaxes of Hipparcos stars agree well with the values measured
by Hipparcos, so the expectation of parallax is the most reliable distance
indicator. The latter are improved by taking extinction into account. The
effective temperature absolute-magnitude diagram of our stars is significantly
improved when these pdfs are used to make the diagram. We use the method of
kinematic corrections devised by Schoenrich, Binney & Asplund to check for
systematic errors for general stars and confirm that the most reliable distance
indicator is the expectation of parallax. For cool dwarfs and low-gravity
giants tends to be larger than the true distance by up to 30 percent. The
most satisfactory distances are for dwarfs hotter than 5500 K. We compare our
distances to stars in 13 open clusters with cluster distances from the
literature and find excellent agreement for the dwarfs and indications that we
are over-estimating distances to giants, especially in young clusters.Comment: 20 pages accepted by MNRAS. Minor changes to the submitted versio
Health Literacy and Cancer Prevention: It’s Not What You Say It’s What They Hear
Background: A growing body of literature documents the relationship between health literacy and important health behaviors and outcomes. Most research to date has focused on print literacy–few studies have examined literacy with respect to spoken information (“spoken health literacy”). We sought to examine the extent to which responses to physician advice about cancer prevention and screening were associated with spoken health literacy.
Methods: Participants listened to 3 simulated physician-patient discussions addressing: 1) Prostate Specific Antigen (PSA) testing; 2) tamoxifen for breast cancer prevention; and 3) colorectal cancer (CRC) screening. The physician provided information on risks and benefits but did not endorse one course of action. Post-vignette questions assessed understanding and reactions to the physician’s advice. Participants had previously completed the Cancer Message Literacy Test-Listening (CMLT-L), a measure of spoken health literacy. Bivariate analyses examined the relationship between CMLT-L scores and comprehension, attitudes, and behavioral intentions.
Results: Four hundred thirty-eight adults from 3 HMORN sites participated. Comprehension: Post-vignette comprehension scores were correlated with CMLT-L scores (r=0.62, p
Discussion: The ability to understand spoken information is a critical component of health literacy. In this study, spoken health literacy influenced patients’ comprehension of, and reaction to spoken health information provided by a physician. The findings that participants scoring in the lowest quartile on the CMLT-L were more likely to respond favorably to physician advice on cancer prevention but were less likely to comprehend content of the vignettes, may indicate that physician mention of a prevention service is interpreted as endorsement of a prevention service in the absence of a full understanding of its risks and benefits
The association between health literacy and cancer-related attitudes, behaviors, and knowledge
Using a multidimensional assessment of health literacy (the Cancer Message Literacy Test-Listening, the Cancer Message Literacy Test-Reading, and the Lipkus Numeracy Scale), the authors assessed a stratified random sample of 1013 insured adults (40-70 years of age). The authors explored whether low health literacy across all 3 domains (n =111) was associated with sets of variables likely to affect engagement in cancer prevention and screening activities: (a) attitudes and behaviors relating to health care encounters and providers, (b) attitudes toward cancer and health, (c) knowledge of cancer screening tests, and (d) attitudes toward health related media and actual media use. Adults with low health literacy were more likely to report avoiding doctor\u27s visits, to have more fatalistic attitudes toward cancer, to be less accurate in identifying the purpose of cancer screening tests, and more likely to avoid information about diseases they did not have. Compared with other participants, those with lower health literacy were more likely to say that they would seek information about cancer prevention or screening from a health care professional and less likely to turn to the Internet first for such information. Those with lower health literacy reported reading on fewer days and using the computer on fewer days than did other participants. The authors assessed the association of low health literacy with colorectal cancer screening in an age-appropriate subgroup for which colorectal cancer screening is recommended. In these insured subjects receiving care in integrated health care delivery systems, those with low health literacy were less likely to be up to date on screening for colorectal cancer, but the difference was not statistically significant
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Ecologies, synergies, and biological systems shaping human milk composition—a report from “Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)” Working Group 2
Human milk is universally recognized as the preferred food for infants during the first 6 mo of life because it provides not only essential and conditionally essential nutrients in necessary amounts but also other biologically active components that are instrumental in protecting, communicating important information to support, and promoting optimal development and growth in infants. Despite decades of research, however, the multifaceted impacts of human milk consumption on infant health are far from understood on a biological or physiological basis. Reasons for this lack of comprehensive knowledge of human milk functions are numerous, including the fact that milk components tend to be studied in isolation, although there is reason to believe that they interact. In addition, milk composition can vary greatly within an individual as well as within and among populations. The objective of this working group within the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project was to provide an overview of human milk composition, factors impacting its variation, and how its components may function to coordinately nourish, protect, and communicate complex information to the recipient infant. Moreover, we discuss the ways whereby milk components might interact such that the benefits of an intact milk matrix are greater than the sum of its parts. We then apply several examples to illustrate how milk is better thought of as a biological system rather than a more simplistic “mixture” of independent components to synergistically support optimal infant health
Genetic diversity and evolution of human metapneumovirus fusion protein over twenty years
<p>Abstract</p> <p>Background</p> <p>Human metapneumovirus (HMPV) is an important cause of acute respiratory illness in children. We examined the diversity and molecular evolution of HMPV using 85 full-length F (fusion) gene sequences collected over a 20-year period.</p> <p>Results</p> <p>The F gene sequences fell into two major groups, each with two subgroups, which exhibited a mean of 96% identity by predicted amino acid sequences. Amino acid identity within and between subgroups was higher than nucleotide identity, suggesting structural or functional constraints on F protein diversity. There was minimal progressive drift over time, and the genetic lineages were stable over the 20-year period. Several canonical amino acid differences discriminated between major subgroups, and polymorphic variations tended to cluster in discrete regions. The estimated rate of mutation was 7.12 × 10<sup>-4 </sup>substitutions/site/year and the estimated time to most recent common HMPV ancestor was 97 years (95% likelihood range 66-194 years). Analysis suggested that HMPV diverged from avian metapneumovirus type C (AMPV-C) 269 years ago (95% likelihood range 106-382 years).</p> <p>Conclusion</p> <p>HMPV F protein remains conserved over decades. HMPV appears to have diverged from AMPV-C fairly recently.</p
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