2,464 research outputs found
Observational Evidence for a Dark Side to NGC5128's Globular Cluster System
We present a study of the dynamical properties of 125 compact stellar systems
(CSSs) in the nearby giant elliptical galaxy NGC5128, using high-resolution
spectra (R 26,000) obtained with VLT/FLAMES. Our results provide evidence for a
new type of star cluster, based on the CSS dynamical mass scaling relations.
All radial velocity (v_r) and line-of-sight velocity dispersion (sigma_los)
measurements are performed with the penalized pixel fitting (ppxf) technique,
which provided sigma_ppxf estimates for 115 targets. The sigma_ppxf estimates
are corrected to the 2D projected half-light radii, sigma_{1/2}, as well as the
cluster cores, sigma_0, accounting for observational/aperture effects and are
combined with structural parameters, from high spatial resolution imaging, in
order to derive total dynamical masses (M_dyn) for 112 members of NGC5128's
star cluster system. In total, 89 CSSs have dynamical masses measured for the
first time along with the corresponding dynamical mass-to-light ratios
(Upsilon_V^dyn). We find two distinct sequences in the Upsilon_V^dyn - M_dyn
plane, which are well approximated by power laws of the forms Upsilon_V^dyn
M_dyn^0.33+\-0.04 and Upsilon_V^dyn - M_dyn^0.79+\-0.04. The shallower sequence
corresponds to the very bright tail of the globular cluster luminosity function
(GCLF), while the steeper relation appears to be populated by a distinct group
of objects which require significant dark gravitating components such as
central massive black holes and/or exotically concentrated dark matter
distributions. This result would suggest that the formation and evolution of
these CSSs are markedly different from the "classical" globular clusters in
NGC5128 and the Local Group, despite the fact that these clusters have
luminosities similar to the GCLF turn-over magnitude. We include a thorough
discussion of myriad factors potentially influencing our measurements.Comment: 21 pages, 14 figures, accepted for publication in The Astrophysical
Journa
Online Resources for Identifying Evidence-Based, Out-of-School Time Programs: A User's Guide
Summarizes general information, select program outcomes, and evidence levels of searchable databases, interactive summaries, and documents online on evidence-based intervention programs. Outlines considerations and assessments for selecting programs
GLP-1 Agonists in Type 1 Diabetes Mellitus: A Review of the Literature
Objective: To review the use of GLP-1 agonists in patients with type 1 diabetes mellitus (T1DM). Data Sources: A search using the MEDLINE database, EMBASE, and Cochrane Database was performed through March 2016 using the search terms glucagon-like peptide 1 (GLP-1) agonists, incretin, liraglutide, exenatide, albiglutide, dulaglutide, type 1 diabetes mellitus. Study Selection and Data Extraction: All English-language trials that examined glycemic end points using GLP- 1 agonists in humans with T1DM were included. Data Synthesis: A total of 9 clinical trials examining the use of GLP-1 agonists in T1DM were identified. On average, hemoglobin A1C (A1C) was lower than baseline, with a maximal lowering of 0.6%. This effect was not significant when tested against a control group, with a relative decrease in A1C of 0.1% to 0.2%. In all trials examined, reported hypoglycemia was low, demonstrating no difference when compared with insulin monotherapy. Weight loss was seen in all trials, with a maximum weight loss of 6.4 kg over 24 weeks. Gastrointestinal adverse effects are potentially limiting, with a significant number of patients in trials reporting nausea. Conclusion: The use of GLP-1 agonists should be considered in T1DM patients who are overweight or obese and not at glycemic goals despite aggressive insulin therapy; however, tolerability of these agents is a potential concern. Liraglutide has the strongest evidence for use and would be the agent of choice for use in overweight or obese adult patients with uncontrolled T1DM
Fibronectin and Cyclic Strain Improve Cardiac Progenitor Cell Regenerative Potential In Vitro.
Cardiac progenitor cells (CPCs) have rapidly advanced to clinical trials, yet little is known regarding their interaction with the microenvironment. Signaling cues present in the microenvironment change with development and disease. This work aims to assess the influence of two distinct signaling moieties on CPCs: cyclic biaxial strain and extracellular matrix. We evaluate four endpoints for improving CPC therapy: paracrine signaling, proliferation, connexin43 expression, and alignment. Vascular endothelial growth factor A (about 900 pg/mL) was secreted by CPCs cultured on fibronectin and collagen I. The application of mechanical strain increased vascular endothelial growth factor A secretion 2-4-fold for CPCs cultured on poly-L-lysine, laminin, or a naturally derived cardiac extracellular matrix. CPC proliferation was at least 25% higher on fibronectin than that on other matrices, especially for lower strain magnitudes. At 5% strain, connexin43 expression was highest on fibronectin. With increasing strain magnitude, connexin43 expression decreased by as much as 60% in CPCs cultured on collagen I and a naturally derived cardiac extracellular matrix. Cyclic mechanical strain induced the strongest CPC alignment when cultured on fibronectin or collagen I. This study demonstrates that culturing CPCs on fibronectin with 5% strain magnitude is optimal for their vascular endothelial growth factor A secretion, proliferation, connexin43 expression, and alignment
The Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes
Two of the most popular forms of protein on the market are whey and casein. Both proteins are derived from milk however the two differ concerning their absorption in the body. This difference between whey and casein proteins could affect the response seen in conjunction with training. PURPOSE: To investigate the potential effects of two types of protein ingestion in conjunction with a controlled resistance training program utilizing college female basketball players. METHODS: 16 NCAA Division III female basketball players were matched according to weight and double-blind randomly assigned to consume 24 grams whey protein (WP) (N = 8, 20 ± 1.9 years, 158 ± 27.3 cm, 66 ± 4.9 kg, 27 ± 4.9 %BF) or 24 grams casein protein (CP) (N = 8, 21 ± 2.8 years, 153 ± 2.9 cm, 68 ± 2.9 kg, 25 ± 5.7 %BF) pre- and post-exercise for eight weeks. Subjects participated in a supervised 4-day per week undulating periodized training program. At 0, 4, and 8 weeks, subjects underwent DEXA body composition analysis. At 0 and 8 weeks subjects underwent 1RM strength, muscle endurance, vertical jump, 5-10-5 and broad jump testing sessions. Data analysis using repeated measures ANOVA are presented as mean ± SD changes from baseline after 60 days. RESULTS: No significant group x time interaction effects were observed among groups in changes in any variable (p \u3e 0.05). A significant time effect was observed for body fat (WP: -2 ± 1.1 %BF; CP: -1 ± 1.6 %BF, p \u3c 0.001), lean mass (WP: 1.5 ± 1 kg; CP: 1.4 ± 1 kg, p \u3c 0.001), fat mass (WP: -1.3 ± 1.2 kg; CP: -0.6 ± 1.4 kg, p \u3c 0.001), leg press 1RM (WP: 88.7 ± 43.9 kg; CP: 90 ± 48.5 kg, p \u3c 0.001), bench press 1RM (WP: 7.5 ± 4.6 kg; CP: 4.3 ±4.5 kg, p = 0.01), vertical jump (WP: 1.6 ± 0.74 in; CP: 1.4 ± 3 in, p \u3c 0.001), 5-10-5 (WP: -0.3 ± 0.2 sec; CP: -0.09 ± 0.42 sec, p \u3c 0.001), and broad jump (WP: 4.1 ± 2.6 in; CP: 5.1 ± 2.8 in, p \u3c 0.001). CONCLUSION: The combination of a controlled undulating resistance training program with pre- and post-exercise protein supplementation is capable of inducing significant changes in performance and body composition. There does not appear to be a difference in the performance enhancing effects of whey versus casein proteins
New g'r'i'z' Photometry of the NGC 5128 Globular Cluster System
We present new photometry for 323 of the globular clusters in NGC 5128
(Centaurus A), measured for the first time in the filter system. The
color indices are calibrated directly to standard stars in the
system and are used to establish the fiducial mean colors for the blue and red
(low and high metallicity) globular cluster sequences. We also use
spectroscopically measured abundances to establish the conversion between the
most metallicity-sensitive colors (, ) and metallicity,
[Fe/H].Comment: 14 pages, 9 figures, accepted in A
How psychologists view and engage with competence in their practice : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University, Albany, New Zealand
The purpose of this study was to gain insight into how psychologists view and engage
with competence and identify the factors that they determine as supporting or
inhibiting competent practice. To date, few studies have examined the elements
psychologists identify as shaping the development of their professional competence. It
is hoped by doing so, strategies can be implemented that develop, maintain, and
enhance competence and encourage active participation in the Continuing
Competence Programme (CCP). Having an agreed definition of the qualities required
to be competent is essential to evaluate, improve, and ensure quality assurance in
psychological practice. Ten psychologists from the clinical and industrial
organisational scopes participated. Semi-structured interviews were used; questions
were designed to act as prompts and to ensure no relevant themes were overlooked.
The interviews were recorded then transcribed and analysed using thematic analysis.
Results indicated that while the participants understood the meaning of competent
practice, how they relate that to their practice and how this influences their
participation in the CCP varies. The participants discussed the value of, and the
challenges associated with, achieving, demonstrating, and measuring competence and
the consequences this has on their practice, their clients and themselves. They also
identified factors that encourage, develop, and maintain competence and those factors
that are threats to competence. It is essential to understand how an individual
perceives competence as this will determine how they view and engage with
competence in their practice. Understanding this will assist with competency
development, maintenance, measurement and demonstration across the professional
lifespan
Development and Testing of the Orion CEV Parachute Assembly System (CPAS)
The Crew Exploration Vehicle (CEV) is an element of the Constellation Program that includes launch vehicles, spacecraft, and ground systems needed to embark on a robust space exploration program. As an anchoring capability of the Constellation Program, the CEV shall be human-rated and will carry human crews and cargo from Earth into space and back again. Coupled with transfer stages, landing vehicles, and surface exploration systems, the CEV will serve as an essential component of the architecture that supports human voyages to the Moon and beyond. In addition, the CEV will be modified, as required, to support International Space Station (ISS) mission requirements for crewed and pressurized cargo configurations. Headed by Johnson Space Center (JSC), NASA selected Jacobs Engineering as the support contractor to manage the overall CEV Parachute Assembly System (CPAS) program development. Airborne Systems was chosen to develop the parachute system components. General Dynamics Ordnance and Tactical Systems (GD-OTS) was subcontracted to Airborne Systems to provide the mortar systems. Thus the CPAS development team of JSC, Jacobs, Airborne Systems and GD-OTS was formed. The CPAS team has completed the first phase, or Generation I, of the design, fabrication, and test plan. This paper presents an overview of the CPAS program including system requirements and the development of the second phase, known as the Engineering Development Unit (EDU) architecture. We also present top level results of the tests completed to date. A significant number of ground and flight tests have been completed since the last CPAS presentation at the 2007 AIAA ADS Conference
Visual art communities of practice: cultivating support for beginning visual art teachers
Visual art teachers, from beginning to veteran, often report experiencing feelings of professional isolation and a desire for content-specific support and collaborative professional learning experiences. Mentoring and Induction Programs (IPs) offered by schools and districts continue to fall short of meeting the needs of beginning visual art teachers in particular. There are a large number of visual art teachers in the state of California, especially in Los Angeles County, yet there are no visual art specific support networks for beginning visual art teachers to help them navigate their first years teaching. Collaborative learning groups, such as communities of practice (CoP), may offer visual art teachers opportunities to learn together and support one another in shared learning, yet none have been formally documented in Los Angeles County as a means of supporting novice art educators. The Exploratorium in San Francisco, CA has established a community practice called the Teacher Induction Program (TIP) to support beginning science teachers with content-specific pedagogy during their first two years of teaching. Using the TIP as a framework, a visual art professional growth support community was outlined for this study based on the needs and concerns of visual art teachers reported throughout the literature. Beginning visual art teachers in Los Angeles county were interviewed to help the researcher better understand their existing and desired supports, as well as their individual needs and concerns as new teachers. The visual art CoP was proposed to them to elicit feedback about its anticipated values (immediate, potential, applied) based on their lived experiences as first or second year PK-12 public school visual art teachers in Los Angeles County
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