860 research outputs found
Constrained Analysis of Topologically Massive Gravity
We quantize the Einstein gravity in the formalism of weak gravitational
fields by using the constrained Hamiltonian method. Special emphasis is given
to the 2+1 spacetime dimensional case where a (topological) Chern-Simons term
is added to the Lagrangian.Comment: 15 pages, IF-UFRJ-21/9
Heterogeneity of left ventricular perfusion during pulmonary edema and microembolism treated with positive end-expiratory pressure and norepinephrine
On the constrained structure of duality symmetric Maxwell theory
The constrained structure of the duality invariant form of Maxwell theory is
considered in the Hamiltonian formulation of Dirac as well as from the
symplectic viewpoint. Compared to the former the latter approach is found to be
more economical and elegant. Distinctions from the constrained analysis of the
usual Maxwell theory are pointed out and their implications are also discussed.Comment: Latex, 12 page
Geometric Quantization of Topological Gauge Theories
We study the symplectic quantization of Abelian gauge theories in
space-time dimensions with the introduction of a topological Chern-Simons term.Comment: 13 pages, plain TEX, IF/UFRJ/9
Interferometric fibre grating characterisation
One of the most important fibre-optic devices to have emerged in the recent years is the fibre grating. It finds applications in DFB and DBR fibre lasers, dispersion compensation and fibre sensors. Full and accurate amplitude and phase (dispersion) characterization of this device is therefore needed. We have demonstrated such a system based on an interferometric technique (figure 1). The signal arm of a fibre Michelson interferometer is phase-modulated with a saw-tooth function to generate an electric signal at the photodetector which carries the optical phase and amplitude information of the reflective fibre device under test (DUT). The amplitude response of the interferometer is directly proportional to the field reflection coefficient, whereas the measured relative phase is related to the time delay response of the device. The set-up is fully automated and uses a Hewlett Packard tunable laser source (1470-1560nm) with wavelength accuracy are high resonance piezoelectric ceramic cylinders which are wrapped round with some turns of fibre
Clinical indicators of occult musculoskeletal pain in aggressive dogs
AGGRESSIVE behaviour by dogs is the most frequent behaviour
problem reported to veterinary behaviour clinics (Bamberger and
Houpt 2006, Fatjo and others 2007). The behaviour is a serious
problem for the victims (Weiss and others 1998) and for the
animals themselves, since it often reflects a negative underlying
emotional state, especially if associated with pain (Bamberger
and Houpt 2006, Hsu and Sun 2010). Pain may lower the dog’s
general threshold for aggressive behaviour, while also encouraging
specific aggressive displays as part of a protective/defensive
response (Rutherford 2002, Muir and others 2004, Landsberg
and others 2013). Beaver (1983) has suggested that more than a
quarter (28.2 per cent) of dogs exhibiting aggression do so
because of a medical condition, including pain, but pain-related
aggression has been considered to account for only a small per
cent of the total caseload in behaviour clinics, that is, 2–3.3 per
cent (Beaver 1983, Borchelt 1983). However, when pain is identi-
fied, the data from Beaver (1983) suggest the prognosis is excellent,
with all cases in her case review reported to have a
successful treatment outcome. A recent small case series of
aggressive dogs with a pain focus indicated that musculoskeletal
pain from hip dysplasia and osteoarthritis of the elbow was the
main cause of pain, occurring in 75 per cent (nine of 12 cases) of
these cases (Camps and others 2012)
Bioecologia e controle de Spodoptera frugiperda em milho.
bitstream/item/67387/1/Documento-344.pd
Total And Segmental Colonic Transit Time In Constipated Patients With Chagas' Disease Without Megaesophagus Or Megacolon.
Manometric and pharmacological tests have shown that motor abnormalities may occur in the non-dilated colons of chagasic patients. In order to investigate the presence of abnormalities of colonic function in constipated patients with Chagas' disease (ChC) without megaesophagus or megacolon, studies of total and segmental colonic transit time with radiopaque markers were performed on 15 ChC patients, 27 healthy volunteers and 17 patients with idiopathic constipation (IC). The values obtained for the control group were similar to those reported in the literature (total colonic time: 34. 1 +/- 15.6 h; right colon: 9.9 +/- 7.3 h; left colon: 10.8 +/- 10 h, and rectosigmoid: 12.6 +/- 9.9 h). Colonic transit time data permitted us to divide both IC and ChC patients into groups with normal transit and those with slow colonic transit. Colonic inertia was detected in 41% of IC patients and in 13% of ChC patients; left colon isolated stasis (hindgut dysfunction) was detected in 12% of IC patients and 7% of ChC patients, and outlet obstruction was detected in 6% of IC patients and 7% of ChC patients. There were no significant differences in total or segmental colonic transit times between slow transit IC and slow transit ChC patients. In conclusion, an impairment of colonic motility was detected in about 30% of constipated patients with Chagas' disease without megaesophagus or megacolon. This subgroup of patients presented no distinctive clinical feature or pattern of colonic dysmotility when compared to patients with slow transit idiopathic constipation.3343-
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