2,048 research outputs found
Going beyond defining: Preschool educators\u27 use of knowledge in their pedagogical reasoning about vocabulary instruction
Previous research investigating both the knowledge of early childhood educators and the support for vocabulary development present in early childhood settings has indicated that both educator knowledge and enacted practice are less than optimal, which has grave implications for children\u27s early vocabulary learning and later reading achievement. Further, the nature of the relationship between educators\u27 knowledge and practice is unclear, making it difficult to discern the best path towards improved knowledge, practice, and children\u27s vocabulary outcomes. The purpose of the present study was to add to the existing literature by using stimulated recall interviews and a grounded approach to examine how 10 preschool educators used their knowledge to made decisions about their moment-to-moment instruction in support of children\u27s vocabulary development. Results indicate that educators were thinking in highly context-specific ways about their goals and strategies for supporting vocabulary learning, taking into account important knowledge of their instructional history with children and of the children themselves to inform their decision making in the moment. In addition, they reported thinking about research-based goals and strategies for supporting vocabulary learning that went beyond simply defining words for children. Implications for research and professional development are discussed
Star Clusters in the Nearby Late-Type Galaxy NGC 1311
Ultraviolet, optical and near infrared images of the nearby (D ~ 5.5 Mpc) SBm
galaxy NGC 1311, obtained with the Hubble Space Telescope, reveal a small
population of 13 candidate star clusters. We identify candidate star clusters
based on a combination of their luminosity, extent and spectral energy
distribution. The masses of the cluster candidates range from ~1000 up to
~100000 Solar masses, and show a strong positive trend of larger mass with
increasing with cluster age. Such a trend follows from the fading and
dissolution of old, low-mass clusters, and the lack of any young super star
clusters of the sort often formed in strong starbursts. The cluster age
distribution is consistent with a bursting mode of cluster formation, with
active episodes of age ~10 Myr, ~100 Myr and ~1 Gyr. The ranges of age and mass
we probe are consistent with those of the star clusters found in quiescent
Local Group dwarf galaxies.Comment: 21 pages, 11 figures, accepted by A
Surface Brightness Profiles of Composite Images of Compact Galaxies at z~4-6 in the HUDF
The Hubble Ultra Deep Field (HUDF) contains a significant number of B, V and
i'-band dropout objects, many of which were recently confirmed to be young
star-forming galaxies at z~4-6. These galaxies are too faint individually to
accurately measure their radial surface brightness profiles. Their average
light profiles are potentially of great interest, since they may contain clues
to the time since the onset of significant galaxy assembly. We separately
co-add V, i' and z'-band HUDF images of sets of z~4,5 and 6 objects,
pre-selected to have nearly identical compact sizes and the roundest shapes.
From these stacked images, we are able to study the averaged radial structure
of these objects at much higher signal-to-noise ratio than possible for an
individual faint object. Here we explore the reliability and usefulness of a
stacking technique of compact objects at z~4-6 in the HUDF. Our results are:
(1) image stacking provides reliable and reproducible average surface
brightness profiles; (2) the shape of the average surface brightness profiles
show that even the faintest z~4-6 objects are resolved; and (3) if late-type
galaxies dominate the population of galaxies at z~4-6, as previous HST studies
have shown, then limits to dynamical age estimates for these galaxies from
their profile shapes are comparable with the SED ages obtained from the
broadband colors. We also present accurate measurements of the sky-background
in the HUDF and its associated 1-sigma uncertainties.Comment: 10 pages, 9 figures, 2 tables, emulateapj; Accepted for publication
in The Astronomical Journa
Specialized care improves outcomes for patients with cirrhosis who require general surgical operations
BACKGROUND:
General surgical operations on patients with cirrhosis have historically been associated with high morbidity and mortality rates. This study examines a contemporary series of patients with cirrhosis undergoing general surgical procedures.
METHODS:
A retrospective evaluation of 358 cirrhotic patients undergoing general surgical operations at a single institution between 2004-2015 was performed. Thirty- and 90-day mortality along with complications and subsequent transplantation rates were examined.
RESULTS:
358 cirrhotic patients were identified. The majority were Child-Turcotte-Pugh class (CTP) A (55.9%) followed by class B (32.4%) and class C (11.7%). Mean MELD score differed significantly between the groups (8.7 vs. 12.1 vs. 20.1; p<0.001). The most common operations were herniorrhaphy (29.9%), cholecystectomy (19.3%), and liver resection (14.5%). The majority of cases were performed semi-electively (68.4%), however, within the CTP C patients most cases were performed emergently (73.8%). Thirty and 90-day mortality for all patients were 5% and 6%, respectively. Mortality rates increased from CTP A to CTP C (30 day: 3.0% vs. 5.2% vs. 14.3%; p = 0.01; 90 day: 4.5% vs. 6.9% vs. 16.7%; p = 0.016). Additionally, 30-day mortality (12.8% vs. 2.3%; p<0.001), 90 day mortality (16.0% vs. 3.4%; p<0.001) were higher for emergent compared to elective cases. A total of 13 (3.6%) patients underwent transplantation †90 days from surgery. No elective cases resulted in an urgent transplantation.
CONCLUSION:
Performing general surgical operations on cirrhotic patients carries a significant morbidity and mortality. This contemporary series from a specialized liver center demonstrates improved outcomes compared to historical series. These data strongly support early referral of cirrhotic patients needing general surgical operation to centers with liver expertise to minimize morbidity and mortality
Organizational evolution and the Olympic Games: the case of sport climbing
This paper discusses the processes underpinning the evolutionary development of sport climbing in recent decades, with a particular focus on the impact of its inclusion in the Olympic Games. New institutionalism and resource-dependence theory provide an analytical and explanatory framework for this study. The research adopted a qualitative method strategy comprising a series of interviews and the analysis of documents, reports, press and social media. The recent inclusion of the sport in the Tokyo 2020 Olympic programme has created challenges, primarily because of strong values inherent within the sport. The research, however, shows that the values of a sport can expand and develop in order to fit the regulatory legitimacy required by inclusion in the Olympic Games. Nonetheless, the research also shows that involvement with the IOC raises questions about who âownsâ the sport
Population Genomics: Whole-Genome Analysis of Polymorphism and Divergence in Drosophila simulans
The population genetic perspective is that the processes shaping genomic variation can be revealed only through simultaneous investigation of sequence polymorphism and divergence within and between closely related species. Here we present a population genetic analysis of Drosophila simulans based on whole-genome shotgun sequencing of multiple inbred lines and comparison of the resulting data to genome assemblies of the closely related species, D. melanogaster and D. yakuba. We discovered previously unknown, large-scale fluctuations of polymorphism and divergence along chromosome arms, and significantly less polymorphism and faster divergence on the X chromosome. We generated a comprehensive list of functional elements in the D. simulans genome influenced by adaptive evolution. Finally, we characterized genomic patterns of base composition for coding and noncoding sequence. These results suggest several new hypotheses regarding the genetic and biological mechanisms controlling polymorphism and divergence across the Drosophila genome, and provide a rich resource for the investigation of adaptive evolution and functional variation in D. simulans
Robot tutors:Welcome or ethically questionable?
Robot tutors provide new opportunities for education. However, they also introduce moral challenges. This study reports a systematic literature re-view (N = 256) aimed at identifying the moral considerations related to ro-bots in education. While our findings suggest that robot tutors hold great potential for improving education, there are multiple values of both (special needs) children and teachers that are impacted (positively and negatively) by its introduction. Positive values related to robot tutors are: psychological welfare and happiness, efficiency, freedom from bias and usability. However, there are also concerns that robot tutors may negatively impact these same values. Other concerns relate to the values of friendship and attachment, human contact, deception and trust, privacy, security, safety and accountability. All these values relate to children and teachers. The moral values of other stakeholder groups, such as parents, are overlooked in the existing literature. The results suggest that, while there is a potential for ap-plying robot tutors in a morally justified way, there are imported stake-holder groups that need to be consulted to also take their moral values into consideration by implementing tutor robots in an educational setting. (from Narcis.nl
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How Emerging Organizations Take Form: The Role of Imprinting and Values in Organizational Bricolage
We examine how emerging organizations acquire shape by drawing on multiple organizational forms, a process we call organizational bricolage. Studying Indymedia London, a grassroots media collective, we propose a grounded theory of organizational bricolage that identifies how various types of organizational forms are selected and how they are instantiated into the organization. Whereas extant research has emphasized imprinting as a primary mechanism shaping newly founded organizations, we point to the additional role of organizational values. Emerging organizations augment their imprinted forms by using ancillary forms aligned with their organizational values and reinforce their core features by differentiating themselves from antagonistic forms that conflict with their values. We contribute to the literature on organizational formation by developing a process model that details how imprinted forms are subsequently modified. Moreover, we extend theories of bricolage by specifying the limits to the relative arbitrariness of bricolage as an activity, and we contribute to the study of organizational values by suggesting that they act as a focusing device shaping organizational structure
Only the Lonely: H I Imaging of Void Galaxies
Void galaxies, residing within the deepest underdensities of the Cosmic Web,
present an ideal population for the study of galaxy formation and evolution in
an environment undisturbed by the complex processes modifying galaxies in
clusters and groups, as well as provide an observational test for theories of
cosmological structure formation. We have completed a pilot survey for the HI
imaging aspects of a new Void Galaxy Survey (VGS), imaging 15 void galaxies in
HI in local (d < 100 Mpc) voids. HI masses range from 3.5 x 10^8 to 3.8 x 10^9
M_sun, with one nondetection with an upper limit of 2.1 x 10^8 M_sun. Our
galaxies were selected using a structural and geometric technique to produce a
sample that is purely environmentally selected and uniformly represents the
void galaxy population. In addition, we use a powerful new backend of the
Westerbork Synthesis Radio Telescope that allows us to probe a large volume
around each targeted galaxy, simultaneously providing an environmentally
constrained sample of fore- and background control sample of galaxies while
still resolving individual galaxy kinematics and detecting faint companions in
HI. This small sample makes up a surprisingly interesting collection of
perturbed and interacting galaxies, all with small stellar disks. Four galaxies
have significantly perturbed HI disks, five have previously unidentified
companions at distances ranging from 50 to 200 kpc, two are in interacting
systems, and one was found to have a polar HI disk. Our initial findings
suggest void galaxies are a gas-rich, dynamic population which present evidence
of ongoing gas accretion, major and minor interactions, and filamentary
alignment despite the surrounding underdense environment.Comment: 53 pages, 18 figures, accepted for publication in AJ. High resolution
available at http://www.astro.columbia.edu/~keejo/kreckel2010.pd
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