1,078 research outputs found
A high-rate telemetry system for the Mariner Mars 1969 mission
High rate telemetry system for Mariner Mars 1969 missio
Phase-locked loop with sideband rejecting properties Patent
Phase locked loop with sideband rejecting properties in continuous wave tracking rada
Strength of Headed Shear Studs in Cold-formed Steel Deck
Results from 57 push-out tests of headed shear studs in cold-formed steel deck are presented. The results are compared to predicted strengths using the American Institute of Steel Construction Load and Resistance Factor Design Specification. The results indicate that the AISC specification does not accurately predict the strength of the shear studs placed in steel deck
The Influence of Land Use/Land Cover on Climatological Values of the Diurnal Temperature Range
The diurnal temperature range (DTR) at weather observation stations that make up the U.S. Historical Climatology Network was evaluated with respect to the predominant land use/land cover associated with the stations within three radii intervals (100, 1000, and 10 000 m) of the stations. Those stations that were associated with predominantly rural land use/land cover (LULC) usually displayed the greatest observed DTR, whereas those associated with urban related land use or land cover displayed the least observed DTR. The results of this study suggest that significant differences in the climatological DTR were observed and could be attributed to the predominant LULC associated with the observation stations. The results also suggest that changes in the predominant LULC conditions, within as great as a 10 000 m radius of an observation station, could significantly influence the climatological DTR. Future changes in the predominant LULC associated with observation sites should be monitored similar to the current practice of monitoring changes in instruments or time of observation at the observations sites
Quality Control of Pre-1948 Cooperative Observer Network Data
A recent comprehensive effort to digitize U.S. daily temperature and precipitation data observed prior to 1948 has resulted in a major enhancement in the computer database of the records of the National Weather Service’s cooperative observer network. Previous digitization efforts had been selective, concentrating on state or regional areas. Special quality control procedures were applied to these data to enhance their value for climatological analysis. The procedures involved a two-step process. In the first step, each individual temperature and precipitation data value was evaluated against a set of objective screening criteria to flag outliers. These criteria included extreme limits and spatial comparisons with nearby stations. The following data were automatically flagged: 1) all precipitation values exceeding 254 mm (10 in.) and 2) all temperature values whose anomaly from the monthly mean for that station exceeded five standard deviations. Addi- tional values were flagged based on differences with nearby stations; in this case, metrics were used to rank outliers so that the limited resources were concentrated on those values most likely to be invalid. In the second step, each outlier was manually assessed by climatologists and assigned one of the four following flags: valid, plausible, questionable, or invalid. In excess of 22 400 values were manually assessed, of which about 48% were judged to be invalid. Although additional manual assessment of outliers might further improve the quality of the database, the procedures applied in this study appear to have been successful in identifying the most flagrant errors
Collaboration networks of the implementation science centers for cancer control: A social network analysis
BACKGROUND: Multi-center research initiatives offer opportunities to develop and strengthen connections among researchers. These initiatives often have goals of increased scientific collaboration which can be examined using social network analysis.
METHODS: The National Cancer Institute (NCI)-funded Implementation Science Centers in Cancer Control (ISC
RESULTS: Of the 192 invitees, 182 network members completed the survey (95%). The most prevalent roles were faculty (60%) and research staff (24%). Almost one-quarter (23%) of members reported advanced expertise in IS, 42% intermediate, and 35% beginner. Most members were female (69%) and white (79%). One-third (33%) of collaboration ties were among members from different centers. Across all collaboration activities, the network had a density of 14%, suggesting moderate cohesion. Degree centralization (0.33) and betweenness centralization (0.07) measures suggest a fairly dispersed network (no single or few central member(s) holding all connections). The most prevalent and densely connected collaboration was in planning/conducting research (1470 ties; 8% density). Practice/policy dissemination had the fewest collaboration, lowest density (284 ties\u27 3% density), and the largest number of non-connected members (n=43). Access to the ISC
CONCLUSIONS: Results establish a baseline for assessing the growth of cross-center collaborations, highlighting specific areas in need of particular growth in network collaborations such as increasing engagement of racial and ethnic minorities and trainees or those with less expertise in IS
Post-landslide soil and vegetation recovery in a dry, montane system is slow and patchy
Landslides are common disturbances in forests around the world, and a major threat to human
life and property. Landslides are likely to become more common in many areas as storms intensify. Forest
vegetation can improve hillslope stability via long, deep rooting across and through failure planes. In the
U.S. Rocky Mountains, landslides are infrequent but widespread when they do occur. They are also extremely
understudied, with little known about the basic vegetation recovery processes and rates of establishment
which restabilize hills. This study presents the first evaluation of post-landslide vegetation recovery
on forested landslides in the southern Rocky Mountains. Six years after a major landslide event, the surveyed
sites have very little regeneration in initiation zones, even when controlling for soil coverage. Soils
are shallower and less nitrogen rich in initiation zones as well. Rooting depth was similar between functional
groups regardless of position on the slide, but deep-rooting trees are much less common in initiation
zones. A lack of post-disturbance tree regeneration in these lower elevation, warm/dry settings, common
across a variety of disturbance types, suggests that complete tree restabilization of these hillslopes is likely
to be a slow or non-existent, especially as the climate warms. Replacement by grasses would protect
against shallow instabilities but not the deeper mass movement events which threaten life and property
Participatory logic modeling in a multi-site initiative to advance implementation science
BACKGROUND: Logic models map the short-term and long-term outcomes that are expected to occur with a program, and thus are an essential tool for evaluation. Funding agencies, especially in the United States (US), have encouraged the use of logic models among their grantees. They also use logic models to clarify expectations for their own funding initiatives. It is increasingly recognized that logic models should be developed through a participatory approach which allows input from those who carry out the program being evaluated. While there are many positive examples of participatory logic modeling, funders have generally not engaged grantees in developing the logic model associated with their own initiatives. This article describes an instance where a US funder of a multi-site initiative fully engaged the funded organizations in developing the initiative logic model. The focus of the case study is Implementation Science Centers in Cancer Control (ISC
METHODS: The reflective case study was collectively constructed by representatives of the seven centers funded under ISC
RESULTS: The initial logic model for ISC
CONCLUSIONS: The IS
Pharmacotherapy and Pregnancy: Highlights from the Third International Conference for Individualized Pharmacotherapy in Pregnancy
To address provider struggles to provide evidence-based, rational drug therapy to pregnant women, this third Conference was convened to highlight the current progress and research in the field. Speakers from academic centers, industry, and governmental institutions spoke about: the Food and Drug Administration’s role in pregnancy pharmacology and the new labeling initiative; drug registries in pregnancy; the pharmacist’s role in medication use in pregnancy; therapeutic areas such as preterm labor, gestational diabetes, nausea and vomiting in pregnancy, and hypertension; breast-feeding and medications; ethical challenges for consent in pregnancy drug studies; the potential for cord blood banks; and concerns about the fetus when studying drugs in pregnancy. The Conference highlighted several areas of collaboration within the current Obstetrics Pharmacology Research Units Network and hoped to educate providers, researchers, and agencies with the common goal to improve the ability to safely and effectively use individualized pharmacotherapy in pregnancy
Our Globally Changing Climate
Since the Third U.S. National Climate Assessment (NCA3) was published in May 2014, new observations along multiple lines of evidence have strengthened the conclusion that Earth's climate is changing at a pace and in a pattern not explainable by natural influences. While this report focuses especially on observed and projected future changes for the United States, it is important to understand those changes in the global context (this chapter). The world has warmed over the last 150 years, especially over the last six decades, and that warming has triggered many other changes to Earth's climate. Evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans. Thousands of studies conducted by tens of thousands of scientists around the world have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; disappearing snow cover; shrinking sea ice; rising sea level; and an increase in atmospheric water vapor. Rainfall patterns and storms are changing, and the occurrence of droughts is shifting
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