12,931 research outputs found
Power law burst and inter-burst interval distributions in the solar wind: turbulence or dissipative SOC ?
We calculate for the first time the probability density functions (PDFs) P of
burst energy e, duration T and inter-burst interval tau for a known turbulent
system in nature. Bursts in the earth-sun component of the Poynting flux at 1
AU in the solar wind were measured using the MFI and SWE experiments on the
NASA WIND spacecraft. We find P(e) and P(T) to be power laws, consistent with
self-organised criticality (SOC). We find also a power law form for P(tau) that
distinguishes this turbulent cascade from the exponential P(tau) of ideal SOC,
but not from some other SOC-like sandpile models. We discuss the implications
for the relation between SOC and turbulence.Comment: 3 pages, 1 figure. Submitted to PRL on 25th February 2000. Revised
version re-submitted on 9th May 2000. Second revised version submitted Phys.
Rev. E on 26th June, 200
A simplex-like search method for bi-objective optimization
We describe a new algorithm for bi-objective optimization, similar to the Nelder Mead simplex
algorithm, widely used for single objective optimization. For diferentiable bi-objective functions on
a continuous search space, internal Pareto optima occur where the two gradient vectors point in
opposite directions. So such optima may be located by minimizing the cosine of the angle between
these vectors. This requires a complex rather than a simplex, so we term the technique the \cosine
seeking complex". An extra beneft of this approach is that a successful search identifes the direction
of the effcient curve of Pareto points, expediting further searches. Results are presented for some
standard test functions. The method presented is quite complicated and space considerations here
preclude complete details. We hope to publish a fuller description in another place
Population Update, Report Number 3
There is more to population study than merely knowing how many people live in a geographical location. Two of the most important other aspects of demography are the age and sex composition of a population. Should planners be thinking about adding space to a grammar school or to a retirement center? By studying age and sex compositions, they will make more accurate decisions. The distribution of a population by age and sex is often shown in a pyramid. The bars in the pyramid (see inside) represent age groups spaced at 5-year intervals. The pyramid is also divided in the middle, with the males at the left and the females at the right. State pyramids for 1960, 1970, and 1975 point up interesting trends. One of the most significant is a lowered birth rate. Thus, the base of the pyramid reflecting the children is shrinking. Statewide services required for the very young may not need expansion. On the other hand, those born around 1960, when the birth rate was higher, are now young adults and form an exaggerated proportion of the state\u27s population. Jobs and higher education are their major concerns. Should we build more colleges and technical schools to accommodate these young people? Look at the age structure at the bottom of the pyramid. In 10 years who is going to fill those schools? Perhaps educators should think in terms of temporary measures to alleviate present difficulties- extension courses, night classes, and the like. Population ratios and indexes like those under the detailed state totals can also be useful. Although pyramids are not portrayed, indexes and ratios as described below are provided for each county
Population Update, Report Number 2
It might be suggested that economics are important in a reverse sort of way. No longer can urban centers offer economic opportunity to potential rural outmigrants, and these people are simply staying at home. Between 1960 and 1970, 53 of South Dakota\u27s 67 counties were losing population. At an extreme, Stanley County dropped 40%; Fall River 30%; and Clark, Harding and Jackson lost nearly one fourth of their inhabitants. In the next 5 years (1970-1975) these same counties had not only stopped losing, but were actually gaining population. While only 14 counties gained population between 1960 and 1970, 38 showed gains between 1970 and 1975. Of the 29 counties still losing population, 19 lost a smaller percentage from 1970 to 1975 than in the decade from 1960 to 1970. Only two counties that gained population between 1960 and 1970 (Yankton and Lawrence) lost population between 1970 and 1975
A Ka-band (32 GHz) beacon link experiment (KABLE) with Mars Observer
A proposal for a Ka-Band (32 GHz) Link Experiment (KABLE) with the Mars Observer mission was submitted to NASA. The experiment will rely on the fourth harmonic of the spacecraft X-band transmitter to generate a 33.6 GHz signal. The experiment will rely also on the Deep Space Network (DSN) receiving station equipped to simultaneously receive X- and Ka-band signals. The experiment will accurately measure the spacecraft-to-Earth telecommunication link performance at Ka-band and X-band (8.4 GHz)
Ecotourism: Where Business and the Environment Meet
Ecotourism has become a powerful economic segment of the wider tourism industry despite a lack of consensual definition and standards that define operating parameters. This paper explores ecotourism by reviewing, the statistics of the phenomenon, potential reasons for its unprecedented growth and attempts at definitional consistency. The pejorative impacts on host cultures and the environment, and positive steps that are rectifying earlier mismanagement in both demand and supply side sectors are also considered. A final section addresses questions that need to be answered by the principles involved in the promotion and supply of the ecotourism business
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Minimal breast milk transfer of rituximab, a monoclonal antibody used in neurological conditions.
ObjectiveTo determine the transfer of rituximab, an anti-CD20 monoclonal antibody widely used for neurologic conditions, into mature breast milk.MethodsBreast milk samples were collected from 9 women with MS who received rituximab 500 or 1,000 mg intravenous once or twice while breastfeeding from November 2017 to April 2019. Serial breast milk samples were collected before infusion and at 8 hours, 24 hours, 7 days, and 18-21 days after rituximab infusion in 4 patients. Five additional patients provided 1-2 samples at various times after rituximab infusion.ResultsThe median average rituximab concentration in mature breast milk was low at 0.063 μg/mL (range 0.046-0.097) in the 4 patients with serial breast milk collection, with an estimated median absolute infant dose of 0.0094 mg/kg/d and a relative infant dose (RID) of 0.08% (range 0.06%-0.10%). Most patients had a maximum concentration at 1-7 days after infusion. The maximum concentration occurred in a woman with a single breast milk sample and was 0.29 μg/mL at 11 days postinfusion, which corresponds with an estimated RID of 0.33%. Rituximab concentration in milk was virtually undetectable by 90 days postinfusion.ConclusionsWe determined minimal transfer of rituximab into mature breast milk. The RID for rituximab was less than 0.4% and well below theoretically acceptable levels of less than 10%. Low oral bioavailability would probably also limit the absorption of rituximab by the newborn. In women with serious autoimmune neurologic conditions, monoclonal antibody therapy may afford an acceptable benefit to risk ratio, supporting both maternal treatment and breastfeeding
Oscillatory oblique stagnation-point flow toward a plane wall
Two-dimensional oscillatory oblique stagnation-point flow toward a plane wall is investigated. The problem is a eneralisation of the steady oblique stagnation-point flow examined by previous workers. Far from the wall, the flow is composed of an irrotational orthogonal stagnation-point flow with a time-periodic strength, a simple shear flow of constant vorticity, and a time-periodic uniform stream. An exact solution of the Navier-Stokes equations is sought for which the flow streamfunction depends linearly on the coordinate parallel to the wall. The problem formulation reduces to a coupled pair of partial differential equations in time and one spatial variable. The first equation describes the oscillatory orthogonal stagnation-point flow discussed by previous workers. The second equation, which couples to the first, describes the oblique component of the flow. A description of the flow velocity field, the instantaneous streamlines, and the particle paths is sought through numerical solutions of the governing equations and via asymptotic analysis
Copper and zinc nutrition experimental results.
Long term copper trial - Newdegate research station, 66N14. Copper, zinc and sulphur residual with DAP for wheat, 78WH66. Copper and zinc residual with dap 78Mo36. Zinc residual with high analysis n.p. fertiliser for wheat 80no31. Zinc residual with high analysis n.p. fertiliser for wheat 79me22, 79me23. Zinc residual with high analysis n.p. fertiliser for wheat 82mo8. Zinc, copper and sulphur residual with DAP, 781G27. Methods of copper application on new land, 85JE48. Evaluation of copper ore 85LG47. Zinc by nitrogen interaction, 85LG28. Zinc residual with DAP, 85LG29. Copper sulphate, copper chelate and copper oxychloride effectiveness for wheat, 85LG26. Zinc sulphate, zinc chelate sprays on wheat, 85LG
Trace element nutrition
South Perth Long term copper trial - Newdegate Research Station – 66N14. Copper, zinc & sulphur residual with DAP for wheat – 78WH66. Copper and zinc residual with DAP – 78MO36. Zinc residual with high analysis N.P. fertilizer for wheat – 79ME22, 79ME23, 80MO8, 80NO31. Cereal responses to zinc Copper and nitrogen interactions on wheat varieties – 83GE2, 83WH1. Barley responses to drilled trace elements – 83BR4, 83BR5. Manganese on wheat – 82NO8. ESPERANCE Zinc residual with high analysis N.P. fertilizer for wheat – 83ES35. Methods of copper application on new land – 83LG6. Copper spray and nitrogen rate applications to wheat supplied with super, copper, zinc and molybdenum no. 1 – 83LG4. Copper sprays on wheat – 84LG3. Zinc sulphate, zinc chelate sprays on wheat – 84LG4. Nitrogen and Hoegrass@ on zinc nutrition of wheat grown on heavy land – 84LG30. Hoegrass@ on zinc nutrition of wheat varieties – 84LGX
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