29,067 research outputs found
Central American Temnocerus Thunberg, 1815 (Coleoptera: Rhynchitidae)
Twenty eight species of Temnocerus Thunberg, 1815 are recognized from Central America (Mexico to Panama) with eight previously described species and 20 new species as follows: T. abdominalis (Voss), T. chiapensis n. sp., T. chiriquensis (Sharp), T. confertus (Sharp), T. cyaneus n. sp., T. ellus n. sp., T. giganteus n. sp., T. guatemalenus (Sharp), T. guerrerensis n. sp., T. herediensis n. sp., T. mexicanus n. sp., T. michoacensis n. sp., T. minutus n. sp., T. niger n. sp., T. oaxacensis n. sp., T. obrieni, n. sp., T. oculatus (Sharp), T. potosi n. sp., T. pseudaeratus n. sp., T. pueblensis n. sp., T. pusillus (Sharp), T. regularis (Sharp), T. rostralis n. sp., T. rugosus n. sp., T. salvensis n. sp., T. tamaulipensis n. sp., T. thesaurus (Sharp) and T. yucatensis n. sp. Rhynchites debilis Sharp is placed in synonymy with Temnocerus guatemalenus (Sharp) and Pselaphorhynchites lindae Hamilton is placed in synonymy with Temnocerus regularis (Sharp). A key to species based on external characters and male genitalia is provided as well as digital images, aedeagus drawings, and map distributions
Negative Group Velocity
The group velocity for pulses in an optical medium can be negative at
frequencies between those of a pair of laser-pumped spectral lines. The gain
medium then can amplify the leading edge of a pulse resulting in a time advance
of the pulse when it exits the medium, as has been recently demonstrated in the
laboratory. This effect has been called superluminal, but, as a classical
analysis shows, it cannot result in signal propgation at speeds greater than
that of light in vacuum.Comment: v3 adds discussion of "rephasing", and adds a figure. v4 adds
references to the early history of negative group velocity, and adds a
figure; thanks to Alex Grani
Relative decompression risks of spacecraft cabin atmospheres
Relative decompression risk studies of spacecraft cabin atmosphere using miniature pig
Generalized Tomonaga-Schwinger equation from the Hadamard formula
A generalized Tomonaga--Schwinger equation, holding on the entire boundary of
a {\em finite} spacetime region, has recently been considered as a tool for
studying particle scattering amplitudes in background-independent quantum field
theory. The equation has been derived using lattice techniques under
assumptions on the existence of the continuum limit. Here I show that in the
context of continuous euclidean field theory the equation can be directly
derived from the functional integral formalism, using a technique based on
Hadamard's formula for the variation of the propagator.Comment: 11 pages, no figure
The effects of temperature gradient and growth rate on the morphology and fatigue properties of MAR-M246(Hf)
MAR-M246(Hf) is a nickel based superalloy used in the turbopump blades of the Space Shuttle main engines. The effects are considered of temperature gradient (G) and growth rate (R) on the microstructure and fatigue properties of this superalloy. The primary dendrite arm spacings were found to be inversely proportional to both temperature gradient and growth rate. Carbide and gamma - gamma prime morphology trends were related to G/R ratios. Weibull analysis of fatigue results shows the characteristic life to be larger by a factor of 10 for the low gradient/fast rate pairing of G and R, while the reliability (beta) was lower
A Survey of the Enteric Group of Fevers in the Middle East, with Special Reference to the Post-War Period, and to the Influence of Immunisation by T.A.B. Vaccine
Abstract Not Provided
The risk of cancer in primary care patients with hypercalcaemia: a cohort study using electronic records.
PublishedJournal ArticleBACKGROUND: The risk of cancer with hypercalcaemia in primary care is unknown. METHODS: This was a cohort study using calcium results in patients aged ⩾40 years in a primary care electronic data set. Diagnoses of cancer in the following year were identified. RESULTS: Participants (54 267) had calcium results: 1674 (3%) were ⩾2.6 mmol l(-1). Hypercalcaemia was strongly associated with cancer, especially in males: OR 2.92, 95% CI 2.17-3.93, P=<0.001; positive predictive value (PPV) 11.5%; females: OR 1.86, 95% CI 1.39-2.50, P<0.001: PPV 4.1%. CONCLUSIONS: Hypercalcaemia is strongly associated with cancer in primary care, with men at most risk, despite hypercalcaemia being more common in women
Relative Decompression Risks of Spacecraft Cabin Atmospheres - Comparision of Gases Using Miniature Pigs Final Report
Using miniature pigs for analysis of altitude decompression sickness and relative decompression hazards of various cabin atmospheres of inert gase
Noise data for a twin-engine commercial jet aircraft flying conventional, steep, and two-segment approaches
Center-line noise measurements of a twin-engine commercial jet aircraft were made during steep landing approach profiles, and during two-segment approach profiles for comparison with similar measurements made during conventional approaches. The steep and two-segment approaches showed significant noise reductions when compared with the -3 deg base line. The measured noise data were also used to develop a method for estimating the noise under the test aircraft at thrust and altitude conditions typical of current landing procedures and of landing procedures under development for the Advanced Air Traffic Control System
Hamilton's theory of turns revisited
We present a new approach to Hamilton's theory of turns for the groups
SO(3) and SU(2) which renders their properties, in particular their
composition law, nearly trivial and immediately evident upon inspection.
We show that the entire construction can be based on binary rotations rather
than mirror reflections.Comment: 7 pages, 4 figure
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