608 research outputs found
Designing an L-THIA Model for ArcGIS 10.2 Using Python 2.7
L-THIA (Long-Term Hydrologic Impact Analysis) is a mature model available as a spreadsheet, a web-based spatial model and as an add-in to the popular geographic information system (GIS) software system ArcGIS 10. The model generally has a method to determine an area of analysis such as a watershed, and then populates the watershed with data on soil and landuse. The model generally requires precipitation data for a long term and uses assumptions about the relationship between landuse, soil, and the chemistry of surface runoff passing across the various landscapes. Input data are landuse and soil map layers and long-term precipitatio
Rapid Prototyping of a Map-Based Android App
This project tries to provide a mobile phone-based solution app named âDriftWatch Pollinator Mapperâ that will allow beekeepers, apiary inspectors, and association staff to easily register and map a hive into the Driftwatch system, where local pesticide applicators will notice it and be aware of the presence of pollinators. The purpose of the mobile application is to speed the process of registering beekeepers within DriftWatch, since many beekeepers have significant trouble using only web-based tools for registering their hive locations, it is hoped a mobile solution is more efficient
Inside help: An integrative review of champions in healthcare-related implementation
Background/aims:
The idea that champions are crucial to effective healthcare-related implementation has gained broad acceptance; yet the champion construct has been hampered by inconsistent use across the published literature. This integrative review sought to establish the current state of the literature on champions in healthcare settings and bring greater clarity to this important construct.
Methods:
This integrative review was limited to research articles in peer-reviewed, English-language journals published from 1980 to 2016. Searches were conducted on the online MEDLINE database via OVID and PubMed using the keyword "champion." Several additional terms often describe champions and were also included as keywords: implementation leader, opinion leader, facilitator, and change agent. Bibliographies of full-text articles that met inclusion criteria were reviewed for additional references not yet identified via the main strategy of conducting keyword searches in MEDLINE. A five-member team abstracted all full-text articles meeting inclusion criteria.
Results:
The final dataset for the integrative review consisted of 199 unique articles. Use of the term champion varied widely across the articles with respect to topic, specific job positions, or broader organizational roles. The most common method for operationalizing champion for purposes of analysis was the use of a dichotomous variable designating champion presence or absence. Four studies randomly allocated of the presence or absence of champions.
Conclusions:
The number of published champion-related articles has markedly increased: more articles were published during the last two years of this review (i.e. 2015-2016) than during its first 30âyears (i.e. 1980-2009).The number of champion-related articles has continued to increase sharply since the year 2000. Individual studies consistently found that champions were important positive influences on implementation effectiveness. Although few in number, the randomized trials of champions that have been conducted demonstrate the feasibility of using experimental design to study the effects of champions in healthcare
A Brane World Perspective on the Cosmological Constant and the Hierarchy Problems
We elaborate on the recently proposed static brane world scenario, where the
effective 4-D cosmological constant is exponentially small when parallel
3-branes are far apart. We extend this result to a compactified model with two
positive tension branes. Besides an exponentially small effective 4-D
cosmological constant, this model incorporates a Randall-Sundrum-like solution
to the hierarchy problem. Furthermore, the exponential factors for the
hierarchy problem and the cosmological constant problem obey an inequality that
is satisfied in nature. This inequality implies that the cosmological constant
problem can be explained if the hierarchy problem is understood. The basic idea
generalizes to the multibrane world scenario. We discuss models with piecewise
adjustable bulk cosmological constants (to be determined by the 5-dimensional
Einstein equation), a key element of the scenario. We also discuss the global
structure of this scenario and clarify the physical properties of the particle
(Rindler) horizons that are present. Finally, we derive a 4-D effective theory
in which all observers on all branes not separated by particle horizons measure
the same Newton's constant and 4-D cosmological constant.Comment: revtex, 63 pages, 8 figures, one table, revised version, more
discussions on the global structure, references adde
Fluctuations of the vacuum energy density of quantum fields in curved spacetime via generalized zeta functions
For quantum fields on a curved spacetime with an Euclidean section, we derive
a general expression for the stress energy tensor two-point function in terms
of the effective action. The renormalized two-point function is given in terms
of the second variation of the Mellin transform of the trace of the heat kernel
for the quantum fields. For systems for which a spectral decomposition of the
wave opearator is possible, we give an exact expression for this two-point
function. Explicit examples of the variance to the mean ratio of the vacuum energy density of a
massless scalar field are computed for the spatial topologies of and , with results of , and
respectively. The large variance signifies the importance
of quantum fluctuations and has important implications for the validity of
semiclassical gravity theories at sub-Planckian scales. The method presented
here can facilitate the calculation of stress-energy fluctuations for quantum
fields useful for the analysis of fluctuation effects and critical phenomena in
problems ranging from atom optics and mesoscopic physics to early universe and
black hole physics.Comment: Uses revte
Vacuum Energy Density Fluctuations in Minkowski and Casimir States via Smeared Quantum Fields and Point Separation
We present calculations of the variance of fluctuations and of the mean of
the energy momentum tensor of a massless scalar field for the Minkowski and
Casimir vacua as a function of an intrinsic scale defined by a smeared field or
by point separation. We point out that contrary to prior claims, the ratio of
variance to mean-squared being of the order unity is not necessarily a good
criterion for measuring the invalidity of semiclassical gravity. For the
Casimir topology we obtain expressions for the variance to mean-squared ratio
as a function of the intrinsic scale (defined by a smeared field) compared to
the extrinsic scale (defined by the separation of the plates, or the
periodicity of space). Our results make it possible to identify the spatial
extent where negative energy density prevails which could be useful for
studying quantum field effects in worm holes and baby universe, and for
examining the design feasibility of real-life `time-machines'.
For the Minkowski vacuum we find that the ratio of the variance to the
mean-squared, calculated from the coincidence limit, is identical to the value
of the Casimir case at the same limit for spatial point separation while
identical to the value of a hot flat space result with a temporal
point-separation. We analyze the origin of divergences in the fluctuations of
the energy density and discuss choices in formulating a procedure for their
removal, thus raising new questions into the uniqueness and even the very
meaning of regularization of the energy momentum tensor for quantum fields in
curved or even flat spacetimes when spacetime is viewed as having an extended
structure.Comment: 41 pages, 2 figure
Identification of Changes in Sleep Across Pregnancy and the Impact on Cardiometabolic Health and Energy Intake in Women with Obesity
This prospective, observational study investigated changes in sleep and the effect on energy intake, gestational weight gain, and cardiometabolic health across pregnancy in 52 healthy pregnant women with obesity. Habitual sleep was assessed by wrist-worn actigraphy (time spent in bed; TIB, total sleep time; TST, and sleep efficiency) in early (13(0)-15(6) weeks) and late (35(0)-36(6)) pregnancy. A change to habitual sleep was defined as change of one-half of the standard deviation of TIB and TST across six consecutive nights from early pregnancy. Energy intake and changes in weight, fasting glucose, insulin, and lipids across pregnancy were compared between women who changed sleep. During early pregnancy, TIB was 9:24±0:08h and varied by 1:37±0:07h across the six nights. TST and sleep efficiency significantly declined from early to late pregnancy (7:03±0:08h to 6:28±0:09h, p<0.001) and (76±0.1% to 71±0.2%, p<0.001), respectively. For women who increased TIB (n=11), fasting glucose decreased (â11.6±4.3%, p<0.01) across pregnancy and they had a trend towards decreased insulin (â57.8±33.5%; p=0.09) and HOMA-IR (â72.4±37.3%; p=0.06) compared to women who decreased TIB (n=13). Women who increased TIB had a significantly lower daily energy intake across pregnancy (â540±163 kcal; p<0.01) and tended to have less gestational weight gain (â147±88 g/week; p=0.10). Changes in TST did not affect plasma markers, energy intake or weight gain. The positive relationship between sleep and cardiometabolic health during pregnancy is explained in part by lower energy intake. We hypothesize lower energy intake is due to a prolonged overnight fast and a decrease in the time available for eating
Safety and Immunogenicity of ChAd63 and MVA ME-TRAP in West African Children and Infants.
Malaria remains a significant global health burden and a vaccine would make a substantial contribution to malaria control. Chimpanzee Adenovirus 63 Modified Vaccinia Ankara Multiple epitope thrombospondin adhesion protein (ME-TRAP) and vaccination has shown significant efficacy against malaria sporozoite challenge in malaria-naive European volunteers and against malaria infection in Kenyan adults. Infants are the target age group for malaria vaccination; however, no studies have yet assessed T-cell responses in children and infants. We enrolled 138 Gambian and Burkinabe children in four different age-groups: 2-6 years old in The Gambia; 5-17 months old in Burkina Faso; 5-12 months old, and also 10 weeks old, in The Gambia; and evaluated the safety and immunogenicity of Chimpanzee Adenovirus 63 Modified Vaccinia Ankara ME-TRAP heterologous prime-boost immunization. The vaccines were well tolerated in all age groups with no vaccine-related serious adverse events. T-cell responses to vaccination peaked 7 days after boosting with Modified Vaccinia Ankara, with T-cell responses highest in 10 week-old infants. Heterologous prime-boost immunization with Chimpanzee Adenovirus 63 and Modified Vaccinia Ankara ME-TRAP was well tolerated in infants and children, inducing strong T-cell responses. We identify an approach that induces potent T-cell responses in infants, which may be useful for preventing other infectious diseases requiring cellular immunity
- âŠ