108 research outputs found
Small Schools: Great Strides, A Study of New Schools in Chicago
This book documents a two-year study and analysis of small schools in Chicago. Using a mixed-method study, gathering both quantitative and qualitative data, the research serves to compare results to previous studies of small urban schools.The study examines the effects of small schools on students, parents, teachers, and community members. Both previous and current research suggest that small school size is correlated with an increase in student attendance, performance, and better sense of community overall.https://educate.bankstreet.edu/books/1022/thumbnail.jp
AXL modulates extracellular matrix protein expression and is essential for invasion and metastasis in endometrial cancer
The receptor tyrosine kinase AXL promotes migration, invasion, and metastasis. Here, we evaluated the role of AXL in endometrial cancer. High immunohistochemical expression of AXL was found in 76% (63/83) of advanced-stage, and 77% (82/107) of high-grade specimens and correlated with worse survival in uterine serous cancer patients. In vitro, genetic silencing of AXL inhibited migration and invasion but had no effect on proliferation of ARK1 endometrial cancer cells. AXL-deficient cells showed significantly decreased expression of phospho-AKT as well as uPA, MMP-1, MMP-2, MMP-3, and MMP-9. In a xenograft model of human uterine serous carcinoma with AXL-deficient ARK1 cells, there was significantly less tumor burden than xenografts with control ARK1 cells. Together, these findings underscore the therapeutic potentials of AXL as a candidate target for treatment of metastatic endometrial cancer
Powerful Winds from Low-Mass Stars: V374 Peg
The rapid rotation (P=0.44 d) of the M dwarf V374Peg (M4) along with its
intense magnetic field point toward magneto-centrifugal acceleration of a
coronal wind. In this work, we investigate the structure of the wind of V374Peg
by means of 3D magnetohydrodynamical (MHD) numerical simulations. For the first
time, an observationally derived surface magnetic field map is implemented in
MHD models of stellar winds for a low mass star. We show that the wind of
V374Peg deviates greatly from a low-velocity, low-mass-loss rate solar-type
wind. We find general scaling relations for the terminal velocities, mass-loss
rates, and spin-down times of highly magnetized M dwarfs. In particular, for
V374Peg, our models show that terminal velocities across a range of stellar
latitudes reach ~(1500-2300) n_{12}^{-1/2} km/s, where n_{12} is the coronal
wind base density in units of 10^{12} cm^{-3}, while the mass-loss rates are
about 4 x 10^{-10} n_{12}^{1/2} Msun/yr. We also evaluate the angular-momentum
loss of V374Peg, which presents a rotational braking timescale ~28
n_{12}^{-1/2} Myr. Compared to observationally derived values from period
distributions of stars in open clusters, this suggests that V374Peg may have
low coronal base densities (< 10^{11} cm^{-3}). We show that the wind ram
pressure of V374Peg is about 5 orders of magnitude larger than for the solar
wind. Nevertheless, a small planetary magnetic field intensity (~ 0.1G) is able
to shield a planet orbiting at 1 AU against the erosive effects of the stellar
wind. However, planets orbiting inside the habitable zone of V374Peg, where the
wind ram pressure is higher, might be facing a more significant atmospheric
erosion. In that case, higher planetary magnetic fields of, at least, about
half the magnetic field intensity of Jupiter, are required to protect the
planet's atmosphere.Comment: 13 pages, 5 figures, 1 table. MNRAS in pres
Field Measurements of Terrestrial and Martian Dust Devils
Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types
Introducing BASE: the Biomes of Australian Soil Environments soil microbial diversity database
Background: Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The 'Biomes of Australian Soil Environments' (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at continental scale. As the characterisation of microbes rapidly expands, the BASE database provides an evolving platform for interrogating and integrating microbial diversity and function.
Findings: BASE currently provides amplicon sequences and associated contextual data for over 900 sites encompassing all Australian states and territories, a wide variety of bioregions, vegetation and land-use types. Amplicons target bacteria, archaea and general and fungal-specific eukaryotes. The growing database will soon include metagenomics data. Data are provided in both raw sequence (FASTQ) and analysed OTU table formats and are accessed via the project's data portal, which provides a user-friendly search tool to quickly identify samples of interest. Processed data can be visually interrogated and intersected with other Australian diversity and environmental data using tools developed by the 'Atlas of Living Australia'.
Conclusions: Developed within an open data framework, the BASE project is the first Australian soil microbial diversity database. The database will grow and link to other global efforts to explore microbial, plant, animal, and marine biodiversity. Its design and open access nature ensures that BASE will evolve as a valuable tool for documenting an often overlooked component of biodiversity and the many microbe-driven processes that are essential to sustain soil function and ecosystem services
Introducing BASE: the Biomes of Australian Soil Environments soil microbial diversity database
Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The ‘Biomes of Australian Soil Environments’ (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at continental scale. As the characterisation of microbes rapidly expands, the BASE database provides an evolving platform for interrogating and integrating microbial diversity and function
The stellar wind cycles and planetary radio emission of the Tau Boo system
Tau Boo is an intriguing planet-host star that is believed to undergo
magnetic cycles similar to the Sun, but with a duration that is about one order
of magnitude smaller than that of the solar cycle. With the use of
observationally derived surface magnetic field maps, we simulate the magnetic
stellar wind of Tau Boo by means of three-dimensional MHD numerical
simulations. As the properties of the stellar wind depend on the particular
characteristics of the stellar magnetic field, we show that the wind varies
during the observed epochs of the cycle. Although the mass loss-rates we find
(~2.7e-12 Msun/yr) vary less than 3 per cent during the observed epochs of the
cycle, our derived angular momentum loss-rates vary from 1.1 to 2.2e32erg. The
spin-down times associated to magnetic braking range between 39 and 78Gyr. We
also compute the emission measure from the (quiescent) closed corona and show
that it remains approximately constant through these epochs at a value of
~10^{50.6} cm^{-3}. This suggests that a magnetic cycle of Tau Boo may not be
detected by X-ray observations. We further investigate the interaction between
the stellar wind and the planet by estimating radio emission from the
hot-Jupiter that orbits at 0.0462 au from Tau Boo. By adopting reasonable
hypotheses, we show that, for a planet with a magnetic field similar to Jupiter
(~14G at the pole), the radio flux is estimated to be about 0.5-1 mJy,
occurring at a frequency of 34MHz. If the planet is less magnetised (field
strengths roughly <4G), detection of radio emission from the ground is
unfeasible due to the Earth's ionospheric cutoff. According to our estimates,
if the planet is more magnetised than that and provided the emission beam
crosses the observer line-of-sight, detection of radio emission from Tau Boo b
is only possible by ground-based instruments with a noise level of < 1 mJy,
operating at low frequencies.Comment: 15 pages, 10 figures, MNRAS accepte
Endovascular strategy or open repair for ruptured abdominal aortic aneurysm: one-year outcomes from the IMPROVE randomized trial.
AIMS: To report the longer term outcomes following either a strategy of endovascular repair first or open repair of ruptured abdominal aortic aneurysm, which are necessary for both patient and clinical decision-making. METHODS AND RESULTS: This pragmatic multicentre (29 UK and 1 Canada) trial randomized 613 patients with a clinical diagnosis of ruptured aneurysm; 316 to an endovascular first strategy (if aortic morphology is suitable, open repair if not) and 297 to open repair. The principal 1-year outcome was mortality; secondary outcomes were re-interventions, hospital discharge, health-related quality-of-life (QoL) (EQ-5D), costs, Quality-Adjusted-Life-Years (QALYs), and cost-effectiveness [incremental net benefit (INB)]. At 1 year, all-cause mortality was 41.1% for the endovascular strategy group and 45.1% for the open repair group, odds ratio 0.85 [95% confidence interval (CI) 0.62, 1.17], P = 0.325, with similar re-intervention rates in each group. The endovascular strategy group and open repair groups had average total hospital stays of 17 and 26 days, respectively, P < 0.001. Patients surviving rupture had higher average EQ-5D utility scores in the endovascular strategy vs. open repair groups, mean differences 0.087 (95% CI 0.017, 0.158), 0.068 (95% CI -0.004, 0.140) at 3 and 12 months, respectively. There were indications that QALYs were higher and costs lower for the endovascular first strategy, combining to give an INB of £3877 (95% CI £253, £7408) or €4356 (95% CI €284, €8323). CONCLUSION: An endovascular first strategy for management of ruptured aneurysms does not offer a survival benefit over 1 year but offers patients faster discharge with better QoL and is cost-effective. CLINICAL TRIAL REGISTRATION: ISRCTN 48334791
How Immunocontraception Can Contribute to Elephant Management in Small, Enclosed Reserves: Munyawana Population as a Case Study
Immunocontraception has been widely used as a management tool to reduce population growth in captive as well as wild populations of various fauna. We model the use of an individual-based rotational immunocontraception plan on a wild elephant, Loxodonta africana, population and quantify the social and reproductive advantages of this method of implementation using adaptive management. The use of immunocontraception on an individual, rotational basis stretches the inter-calving interval for each individual female elephant to a management-determined interval, preventing exposing females to unlimited long-term immunocontraception use (which may have as yet undocumented negative effects). Such rotational immunocontraception can effectively lower population growth rates, age the population, and alter the age structure. Furthermore, such structured intervention can simulate natural process such as predation or episodic catastrophic events (e.g., drought), which regulates calf recruitment within an abnormally structured population. A rotational immunocontraception plan is a feasible and useful elephant population management tool, especially in a small, enclosed conservation area. Such approaches should be considered for other long-lived, social species in enclosed areas where the long-term consequences of consistent contraception may be unknown
Physiological Correlates of Volunteering
We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation
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