2,767 research outputs found
Characterization of Trypanosoma brucei gambiense variant surface glycoprotein LiTat 1.5
At present, all available diagnostic antibody detection tests for Trypanosoma brucei gambiense human African trypanosomiasis are based on predominant variant surface glycoproteins (VSGs), such as VSG LiTat 1.5. During investigations aiming at replacement of the native VSGs by recombinant proteins or synthetic peptides, the sequence of VSG LiTat 1.5 was derived from cDNA and direct N-terminal amino acid sequencing. Characterization of the VSG based on cysteine distribution in the amino acid sequence revealed an unusual cysteine pattern identical to that of VSG Kinu 1 of T. b. brucei. Even though both VSGs lack the third of four conserved cysteines typical for type A N-terminal domains, they can be classified as type A
Photon density of states for deformed surfaces
A new approach to the Helmholtz spectrum for arbitrarily shaped boundaries
and a rather general class of boundary conditions is introduced. We derive the
boundary induced change of the density of states in terms of the free Green's
function from which we obtain both perturbative and non-perturbative results
for the Casimir interaction between deformed surfaces. As an example, we
compute the lateral electrodynamic Casimir force between two corrugated
surfaces over a wide parameter range. Universal behavior, fixed only by the
largest wavelength component of the surface shape, is identified at large
surface separations. This complements known short distance expansions which are
also reproduced.Comment: 8 pages, J Phys A Special Issue QFEXT0
Field evaluation of the CATT/Trypanosoma brucei gambiense on blood-impregnated filter papers for diagnosis of human African trypanosomiasis in southern Sudan.
Most Human African Trypanosomiasis (HAT) control programmes in areas endemic for Trypanosoma brucei gambiense rely on a strategy of active mass screening with the Card Agglutination Test for Trypanosomiasis (CATT)/T. b. gambiense. We evaluated the performance, stability and reproducibility of the CATT/T. b. gambiense on blood-impregnated filter papers (CATT-FP) in Kajo-Keji County, South-Sudan, where some areas are inaccessible to mobile teams. The CATT-FP was performed with a group of 100 people with a positive CATT on whole blood including 17 confirmed HAT patients and the results were compared with the CATT on plasma (CATT-P). The CATT-FP was repeated on impregnated filter papers stored at ambient and refrigerated temperature for 1, 3, 7 and 14 days. Another 82 patients with HAT, including 78 with a positive parasitology, were tested with the CATT-FP and duplicate filter paper samples were sent to a reference laboratory to assess reproducibility. The CATT-FP was positive in 90 of 99 patients with HAT (sensitivity: 91%). It was less sensitive than the CATT-P (mean dilution difference: -2.5). There was no significant loss of sensitivity after storage for up to 14 days both at ambient and cool temperature. Reproducibility of the CATT-FP was found to be excellent (kappa: 0.84). The CATT-FP can therefore be recommended as a screening test for HAT in areas where the use of CATT-P is not possible. Further studies on larger population samples in different endemic foci are still needed before the CATT-FP can be recommended for universal use
Searches for R-parity violating Supersymmetry at LEP 2
Searches for pair-production of Supersymmetric particles under the assumption that R-parity is not conserved have been performed using the data collected by ALEPH at centre-of-mass energies of 130-172 GeV. The results for a dominant R-parity violating coupling LLE, for which the observed candidate events in the data are in agreement with the SM expectation, translate into lower limits on the mass of charginos, neutralinos, sleptons, sneutrinos and squarks. We also give preliminary results on the search for charginos, sleptons and sneutrinos via a dominant LQD coupling, and discuss the implications of our results on the R-parity violating interpretations of the recently reported excess of high Q2 events at HERA, and the ALEPH four jet anomaly
Polarized Proton Beams from Laser-induced Plasmas
We report on the concept of an innovative source to produce polarized
proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven
plasma accelerator. Spin effects have been implemented into the PIC simulation
code VLPL to make theoretical predictions about the behavior of proton spins in
laser-induced plasmas. Simulations of spin-polarized targets show that the
polarization is conserved during the acceleration process. For the experimental
realization, a polarized HCl gas-jet target is under construction using the
fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and
simultaneously circular polarized light of the fifth harmonic to
photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their
degree of polarization is measured with a Lamb-shift polarimeter. The final
experiments, aiming at the first observation of a polarized particle beam from
laser-generated plasmas, will be carried out at the 10 PW laser system SULF at
SIOM/Shanghai.Comment: 7 pages, 7 figure
\u27Trust\u27 and \u27confidence\u27 as socio-technical problems in the transformation of energy systems
Background: For the development of a sustainable energy system, the public’s contribution to the sustainment of the system’s current operations will become vital. The public’s role is expected to change from that of passive service abiders to active service providers, as anticipated by visions of prosumers, smart grids, demand side management, virtual power plants, and electric vehicle management. Smart technology and new business models will increase system complexity and the experience of uncertainty and risk for all parties. Actionability of the public’s participation in the opportunities arising from the transformation of energy systems will become a problem.
Methods: With a qualitative functionalist method, we analyze the prerequisites of the public’s participation: the capacity of social mechanisms, such as trust, for the solution of social problems. Functional problems affect the continuation of communication, i.e., the possibility of the sustainment of social reality. We isolate three case studies that illustrate concrete effects of trust, distrust, and confidence on three parties, respectively: consumers, investors, and those affected by grid extensions.
Results and conclusions: We argue that the social mechanisms of trust and confidence are more vital for consumers, investors, and those affected than previous research has noticed. These mechanisms determine the achievement of sustainability in energy systems by sustaining actionability as a favorable expectation (trust, confidence), or an unfavorable expectation (lack of trust, distrust). Even lack of trust and distrust can be valuable contributors on the road to sustainability, since they uncover flaws and setbacks of a fledgling smart grid
Louse flies holding on mammals' hair: Comparative functional morphology of specialized attachment devices of ectoparasites (Diptera: Hippoboscoidea)
Hippoboscidae and Nycteribiidae of the dipteran superfamily Hippoboscoidea are obligate ectoparasites, which feed on the blood of different mammals. Due to their limited flight capability, the attachment system on all tarsi is of great importance for a secure grasp onto their host and thus for their survival. In this study, the functional morphology of the attachment system of two hippoboscid species and two nycteribiid species was compared in their specificity to the host substrate. Based on data from scanning electron microscopy and confocal laser scanning microscopy, it was shown that the attachment systems of both Hippoboscidae and Nycteribiidae (Hippoboscoidea) differ greatly from that of other calyptrate flies and are uniform within the respective families. All studied species have an attachment system with two monodentate claws and two pulvilli. The claws and pulvilli of the Hippoboscidae are asymmetric, which is an adaptation to the fur of even-toed ungulates (Artiodactyla). The fur of these mammals possesses both, thinner woolen and thicker coat hair; thus, the asymmetry of the attachment system of the hippoboscid species enables a secure attachment to all surfaces of their hosts. The claws and pulvilli of the nyceribiid species do not show an asymmetry, since the fur of their bat (Chiroptera) hosts consists of hairs with the same thickness. The claws are important for the attachment to mammals' fur, because they enable a secure grip by mechanical interlocking of the hairs through the claws. Additionally, well-developed pulvilli are able to attach on thicker hairs of Artiodactyla or on smooth substrates such as the skin
Shape Isomerism at N = 40: Discovery of a Proton Intruder in 67Co
The nuclear structure of 67Co has been investigated through 67Fe beta-decay.
The 67Fe isotopes were produced at the LISOL facility in proton-induced fission
of 238U and selected using resonant laser ionization combined with mass
separation. The application of a new correlation technique unambiguously
revealed a 496(33) ms isomeric state in 67Co at an unexpected low energy of 492
keV. A 67Co level scheme has been deduced. Proposed spin and parities suggest a
spherical (7/2-) 67Co ground state and a deformed first excited (1/2-) state at
492 keV, interpreted as a proton 1p-2h prolate intruder state.Comment: 4 pages, 5 figures, preprint submitted to Physical Review Letter
- …