6,289 research outputs found
Exploring Foundation Financial Investments in Nonprofit Capacity Building
Provides statistics related to the nature and characteristics of foundation financial investments, based on recent surveys. Includes recommendations for future actions, and bibliographical references
Existence and conditional energetic stability of solitary gravity-capillary water waves with constant vorticity
We present an existence and stability theory for gravity-capillary solitary
waves with constant vorticity on the surface of a body of water of finite
depth. Exploiting a rotational version of the classical variational principle,
we prove the existence of a minimiser of the wave energy subject
to the constraint , where is the wave momentum
and . Since and are both conserved
quantities a standard argument asserts the stability of the set of
minimisers: solutions starting near remain close to in a
suitably defined energy space over their interval of existence.
In the applied mathematics literature solitary water waves of the present
kind are described by solutions of a Korteweg-deVries equation (for strong
surface tension) or a nonlinear Schr\"{o}dinger equation (for weak surface
tension). We show that the waves detected by our variational method converge
(after an appropriate rescaling) to solutions of the appropriate model equation
as Comment: Corrected version. To appear in Proceedings of the Royal Society of
Edinburgh: Section
A dimension-breaking phenomenon for water waves with weak surface tension
It is well known that the water-wave problem with weak surface tension has
small-amplitude line solitary-wave solutions which to leading order are
described by the nonlinear Schr\"odinger equation. The present paper contains
an existence theory for three-dimensional periodically modulated solitary-wave
solutions which have a solitary-wave profile in the direction of propagation
and are periodic in the transverse direction; they emanate from the line
solitary waves in a dimension-breaking bifurcation. In addition, it is shown
that the line solitary waves are linearly unstable to long-wavelength
transverse perturbations. The key to these results is a formulation of the
water wave problem as an evolutionary system in which the transverse horizontal
variable plays the role of time, a careful study of the purely imaginary
spectrum of the operator obtained by linearising the evolutionary system at a
line solitary wave, and an application of an infinite-dimensional version of
the classical Lyapunov centre theorem.Comment: The final publication is available at Springer via
http://dx.doi.org/10.1007/s00205-015-0941-
Aerobee 350, flight 17.03 GE - Instrumentation information and calibration data
Airborne instrumentation system on Aerobee 350 sounding rocke
Spears or ploughshares : multiple indicators of activity related stress and social status in four Early Medieval populations from the North East of England
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Arkansas Cotton Variety Test 2003
The primary aim of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed dealers establish marketing strategies and assists producers in choosing varieties to plant. In this way, the annual test facilitates the inclusion of new, improved genetic material in Arkansas cotton production
Incorporation of calcium salts into xanthan gum matrices: hydration, erosion and drug release characteristics.
A systematic review of the global seasonality of infections caused by Acinetobacter species in hospitalized patients
Background: Acinetobacter is a leading multidrug resistant pathogen in hospitals worldwide that has been seen to exhibit periodic surges during summer months. However, winter peaks and lack of seasonality have also been noted.
Objectives: To systematically collate and examine the evidence describing seasonal patterns in the incidence of Acinetobacter infection in hospitalized patients.
Data sources: MEDLINE/Ovid, EMBASE, Scopus and Web of Science.
Study eligibility criteria: Longitudinal observational studies investigating seasonal variation in the incidence of Acinetobacter infection.
Participants: Patients receiving hospital care.
Interventions: Routine hospital care.
Methods: Systematic review with narrative evidence synthesis structured around clinical and methodological heterogeneity and internal validity of retrieved studies, seasonal patterns and risk factors detected, and stated hypotheses of mechanisms underlying seasonality. To examine consistency in reported seasonal patterns across different conditions, monthly incidence data were extracted, standardised, weighted and presented graphically.
Results: Twenty-five studies reporting 37006 cases of Acinetobacter infection or colonization during 1954 months of follow-up were reviewed. Standardised monthly incidence data pooled across studies exhibited a global seasonal pattern with an incidence peak in summer/warmer months and a trough in winter/colder months. This seasonal pattern remained consistent under different weighting schemes accounting for study size, length of follow-up and overall quality assessment rating. Seasonality persisted in different clinical settings and for different types and sources of infection. Nine studies provided consistent evidence of temperature-associated variation in Acinetobacter incidence, while there were controversial findings regarding other environmental variables. No study detected patient-related or clinical practice-related seasonal variation in Acinetobacter incidence.
Conclusions: Despite substantial clinical and methodological heterogeneity in retrieved studies, a consistent global seasonal pattern in Acinetobacter infection incidence was evident in this review. This merits attention when designing or evaluating infection control interventions in hospitals. Future research should focus on elucidating driving mechanisms underlying the observed seasonality
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