1,919 research outputs found
Superintendent and School Board Relations: Impacting Achievement through Collaborative Understanding of Roles and Responsibilities
One of the most important and influential persons in the governance structure of the local school district is the Superintendent of Schools. Functioning as the CEO of the district, the superintendent is responsible for a myriad of functions. Examples include daily operations inclusive of transportation and finance, curriculum and policy implementation, media relations, and empowering leaders. However, as Meador (2014) contends, a crucial role is that of board liaison. The Superintendent is responsible for keeping the board informed, making recommendations regarding district operations, and setting the board agenda. It is interesting to note that the superintendent does participate in board meetings, but in an advisory capacity. Finally, the superintendent is responsible for enacting all mandates approved by the school board
Performance characteristics of an electromagnetic pump
The linear induction pump (76 laminations, 0.125-inch duct thickness, 0.319-inch air gap) can produce a maximum no-flow pressure of 0.734 psi and can pump 0.450 gpm against a 0.2 psi head. With an air gap of 0.443 inch and a pump section having a 0.250-inch duct thickness, the maximum no-flow pressure decreases to 0.551 psi, but the improved hydraulic efficiency of the larger duct permits circulation of 0.9 gpm against a 0.2 psi head. The improvement in magnetic field strength from 78 gauss/amp at 0.443 inch air gap to 103 gauss/amp at 0.310 inch air gap indicates the need for minimizing the pump air gap while maintaining a duct thickness consistent with good hydraulic efficiency
Assessing the Impact of Vertical Land Motion on Twentieth Century Global Mean Sea Level Estimates
Near-global and continuous measurements from satellite altimetry have provided accurate estimates of global mean sea level in the past two decades. Extending these estimates further into the past is a challenge using the historical tide gauge records. Not only is sampling nonuniform in both space and time, but tide gauges are also affected by vertical land motion (VLM) that creates a relative sea level change not representative of ocean variability. To allow for comparisons to the satellite altimetry estimated global mean sea level (GMSL), typically the tide gauges are corrected using glacial isostatic adjustment (GIA) models. This approach, however, does not correct other sources of VLM that remain in the tide gauge record. Here we compare Global Positioning System (GPS) VLM estimates at the tide gauge locations to VLM estimates from GIA models, and assess the influence of non-GIA-related VLM on GMSL estimates. We find that the tide gauges, on average, are experiencing positive VLM (i.e., uplift) after removing the known effect of GIA, resulting in an increase of 0.24 ± 0.08 mm yr−1 in GMSL trend estimates from 1900 to present when using GPS-based corrections. While this result is likely dependent on the subset of tide gauges used and the actual corrections used, it does suggest that non-GIA VLM plays a significant role in twentieth century estimates of GMSL. Given the relatively short GPS records used to obtain these VLM estimates, we also estimate the uncertainty in the GMSL trend that results from limited knowledge of non-GIA-related VLM
Late Quaternary slip rates across the central Tien Shan, Kyrgyzstan, central Asia
Slip rates across active faults and folds show that late Quaternary faulting is distributed across the central Tien Shan, not concentrated at its margins. Nearly every intermontane basin contains Neogene and Quaternary syntectonic strata deformed by Holocene north‐south shortening on thrust or reverse faults. In a region that spans two thirds of the north‐south width of the central Tien Shan, slip rates on eight faults in five basins range from ∼0.1 to ∼3 mm/yr. Fault slip rates are derived from faulted and folded river terraces and from trenches. Radiocarbon, optically stimulated luminescence, and thermoluminescence ages limit ages of terraces and aid in their regional correlation. Monte Carlo simulations that sample from normally distributed and discrete probability distributions for each variable in the slip rate calculations generate most likely slip rate values and 95% confidence limits. Faults in basins appear to merge at relatively shallow depths with crustal‐scale ramps that underlie mountain ranges composed of pre‐Cenozoic rocks. The sum and overall pattern of late Quaternary rates of shortening are similar to current rates of north‐south shortening measured using Global Positioning System geodesy. This similarity suggests that deformation is concentrated along major fault zones near range‐basin margins. Such faults, separated by rigid blocks, accommodate most of the shortening in the upper crust
Reviews
The following publications have been reviewed by the mentioned authors;Design: Science: Method by R. Jacques and J. A. Powell, reviewed by Sydney GregoryAfrican Textiles and Dyeing Techniques by Claire Polakoff, reviewed by Dorothea KayThe Complete Calligrapher by Fredrick Wong, reviewed by John LancasterSacred Calligraphy of the East by John Stevens, reviewed by John LancasterSchool Crafts - A Folio of Ideas by the Educational Insitutte of Design, Craft and Technology, reviewed by J. W. ThompsonDesign Briefs by the Educational Insitutte of Design, Craft and Technology, reviewed by J. W. ThompsonA Further Portfolio of Ideas by the Educational Insitutte of Design, Craft and Technology, reviewed by J. W. ThompsonThe Medieval Monastery, Five Shropshire Monasteries by the Department of Education, University of Keele, reviewed by Nigel HallProjects and Designs in Metalwork by Ian Punter, reviewed by Ray BlandColor Science for Lighting the Stage by W. B. Warfel and W. R. Klappert, reviewed by A. VargoScottish Technical Education Modules reviewed by John Cav
The natural resources of Humboldt Bay
In spite of its past abuses by man, Humboldt Bay is one of the few coastal estuaries remaining in California that has not been rendered largely unsuitable for wildlife by commercial development, dredging, filling or pollution. Its importance is emphasized considering that about 65 percent of the State's original estuarine tidelands have already been destroyed. The people have demonstrated their concern for our dwindling natural resources. If we are to preserve what remains it will be necessary for the people to exercise the wisest possible use of these resources.
Because of the importance of coastal wetlands to the fish and wildlife of California, the Department of Fish and Game has initiated a high priority statewide inventory of these wetlands. This publication is an integral part of that program. It is intended as a guide for citizens, planners,
administrators and all others interested in the use and development of coastal lands and waters.
The Department has been charged with the responsibility of protecting and maintaining the fish and wildlife resources of the State. This publication is directed towards meeting
this responsibility by outlining the specific resources and recreational aspects of Humboldt Bay, elucidating problems,
and recommending courses of action for future development.
Preservation of the Humboldt Bay resources is much more than a local issue. What is done or not done here can have statewide, national and international implications. It also must be recognized that there is an obligation to future generations. Decisions made today will affect all those
who follow in our footsteps. (200pp.
The Identification of the X-ray Counterpart to PSR J2021+4026
We report the probable identification of the X-ray counterpart to the
gamma-ray pulsar PSR J2021+4026 using imaging with the Chandra X-ray
Observatory ACIS and timing analysis with the Fermi satellite. Given the
statistical and systematic errors, the positions determined by both satellites
are coincident. The X-ray source position is R.A. 20h21m30.733s, Decl. +40 deg
26 min 46.04sec (J2000) with an estimated uncertainty of 1.3 arsec combined
statistical and systematic error. Moreover, both the X-ray to gamma-ray and the
X-ray to optical flux ratios are sensible assuming a neutron star origin for
the X-ray flux. The X-ray source has no cataloged infrared-to-visible
counterpart and, through new observations, we set upper limits to its optical
emission of i' >23.0 mag and r' > 25.2mag. The source exhibits an X-ray
spectrum with most likely both a powerlaw and a thermal component. We also
report on the X-ray and visible light properties of the 43 other sources
detected in our Chandra observation.Comment: Accepted for publication in the Astrophysical Journa
Towards Molecular Simulations that are Transparent, Reproducible, Usable By Others, and Extensible (TRUE)
Systems composed of soft matter (e.g., liquids, polymers, foams, gels,
colloids, and most biological materials) are ubiquitous in science and
engineering, but molecular simulations of such systems pose particular
computational challenges, requiring time and/or ensemble-averaged data to be
collected over long simulation trajectories for property evaluation. Performing
a molecular simulation of a soft matter system involves multiple steps, which
have traditionally been performed by researchers in a "bespoke" fashion,
resulting in many published soft matter simulations not being reproducible
based on the information provided in the publications. To address the issue of
reproducibility and to provide tools for computational screening, we have been
developing the open-source Molecular Simulation and Design Framework (MoSDeF)
software suite. In this paper, we propose a set of principles to create
Transparent, Reproducible, Usable by others, and Extensible (TRUE) molecular
simulations. MoSDeF facilitates the publication and dissemination of TRUE
simulations by automating many of the critical steps in molecular simulation,
thus enhancing their reproducibility. We provide several examples of TRUE
molecular simulations: All of the steps involved in creating, running and
extracting properties from the simulations are distributed on open-source
platforms (within MoSDeF and on GitHub), thus meeting the definition of TRUE
simulations
Eight gamma-ray pulsars discovered in blind frequency searches of Fermi LAT data
We report the discovery of eight gamma-ray pulsars in blind frequency
searches using the LAT, onboard the Fermi Gamma-ray Space Telescope. Five of
the eight pulsars are young (tau_c10^36 erg/s), and
located within the Galactic plane (|b|<3 deg). The remaining three are older,
less energetic, and located off the plane. Five pulsars are associated with
sources included in the LAT bright gamma-ray source list, but only one, PSR
J1413-6205, is clearly associated with an EGRET source. PSR J1023-5746 has the
smallest characteristic age (tau_c=4.6 kyr) and is the most energetic
(Edot=1.1E37 erg/s) of all gamma-ray pulsars discovered so far in blind
searches. PSRs J1957+5033 and J2055+25 have the largest characteristic ages
(tau_c~1 Myr) and are the least energetic (Edot~5E33 erg/s) of the
newly-discovered pulsars. We present the timing models, light curves, and
detailed spectral parameters of the new pulsars. We used recent XMM
observations to identify the counterpart of PSR J2055+25 as XMMU
J205549.4+253959. In addition, publicly available archival Chandra X-ray data
allowed us to identify the likely counterpart of PSR J1023-5746 as a faint,
highly absorbed source, CXOU J102302.8-574606. The large X-ray absorption
indicates that this could be among the most distant gamma-ray pulsars detected
so far. PSR J1023-5746 is positionally coincident with the TeV source HESS
J1023-575, located near the young stellar cluster Westerlund 2, while PSR
J1954+2836 is coincident with a 4.3 sigma excess reported by Milagro at a
median energy of 35 TeV. Deep radio follow-up observations of the eight pulsars
resulted in no detections of pulsations and upper limits comparable to the
faintest known radio pulsars, indicating that these can be included among the
growing population of radio-quiet pulsars in our Galaxy being uncovered by the
LAT, and currently numbering more than 20.Comment: Submitted to Ap
Recommended from our members
Values for preventing influenza-related morbidity and vaccine adverse events in children
BACKGROUND: Influenza vaccination recently has been recommended for children 6–23 months old, but is not currently recommended for routine use in non-high-risk older children. Information on disease impact, costs, benefits, risks, and community preferences could help guide decisions about which age and risk groups should be vaccinated and strategies for improving coverage. The objective of this study was to measure preferences and willingness-to-pay for changes in health-related quality of life associated with uncomplicated influenza and two rarely-occurring vaccination-related adverse events (anaphylaxis and Guillain-Barré syndrome) in children. METHODS: We conducted telephone interviews with adult members selected at random from a large New England HMO (n = 112). Respondents were given descriptions of four health outcomes: uncomplicated influenza in a hypothetical 1-year-old child of their own, uncomplicated influenza in a hypothetical 14-year-old child of their own, anaphylaxis following vaccination, and Guillain-Barré syndrome. "Uncomplicated influenza" did not require a physician's visit or hospitalization. Preferences (values) for these health outcomes were measured using time-tradeoff and willingness-to-pay questions. Time-tradeoff questions asked the adult to assume they had a child and to consider how much time from the end of their own life they would be willing to surrender to avoid the health outcome in the child. RESULTS: Respondents said they would give a median of zero days of their lives to prevent an episode of uncomplicated influenza in either their (hypothetical) 1-year-old or 14-year-old, 30 days to prevent an episode of vaccination-related anaphylaxis, and 3 years to prevent a vaccination-related case of Guillain-Barré syndrome. Median willingness-to-pay to prevent uncomplicated influenza in a 1-year-old was 100, anaphylaxis 4000. The median willingness-to-pay for an influenza vaccination for their children with no risk of anaphylaxis or Guillain-Barré syndrome was 100, respectively. CONCLUSION: Most respondents said they would not be willing to trade any time from their own lives to prevent uncomplicated influenza in a child of their own, and the time traded did not vary by the age of the hypothetical affected child. However, adults did indicate a willingness-to-pay to prevent uncomplicated influenza in children, and that they would give more money to prevent the illness in a 1-year-old than in a 14-year-old. Respondents also indicated a willingness to pay a premium for a vaccine without any risk of severe complications
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