1,279 research outputs found
Novel expression of Haemonchus contortus vaccine candidate aminopeptidase H11 using the free-living nematode Caenorhabditis elegans
With the problem of parasitic nematode drug resistance increasing, vaccine development offers an alternative sustainable control approach. For some parasitic nematodes, native extracts enriched for specific proteins are highly protective. However, recombinant forms of these proteins have failed to replicate this protection. This is thought to be due to differences in glycosylation and/or conformation between native and recombinant proteins. We have exploited the free-living nematode Caenorhabditis elegans to examine its suitability as an alternative system for recombinant expression of parasitic nematode vaccine candidates. We focussed on Haemonchus contortus aminopeptidase H11 glycoprotein, which is enriched in a gut membrane fraction capable of inducing significant protection against this important ovine gastrointestinal nematode. We show that H. contortus H11 expressed in C. elegans is enzymatically active and MALDI mass spectrometry identifies similar di- and tri-fucosylated structures to those on native H11, with fucose at the 3- and/or 6-positions of the proximal GlcNAc. Some glycan structural differences were observed, such as lack of LDNF. Serum antibody to native H11 binds to C. elegans recombinant H11 and most of the antibody to rH11 or native H11 is directed to glycan moieties. Despite these similarities, no reduction in worm burden or faecal egg count was observed following immunisation of sheep with C. elegans-expressed recombinant H11 protein. The findings suggest that the di- and tri-fucosylated N-glycans expressed on rH11 do not contribute to the protective effect of H11 and that additional components present in native H11-enriched extract are likely required for enhancing the antibody response necessary for protection
Lagrangian description of world-line deviations
We introduce a Lagrangian which can be varied to give both the equation of
motion and world-line deviations of spinning particles simultaneously.Comment: to appear in IJT
On the Integration of Positive Psychology and the Psychology/Spirituality: Logical, Normative, and Methodological Questions
When it comes to the integration of positive psychology and the psychology of religion/spirituality (R/S), there are three second-order, philosophical questions that need answering: Can these two fields be integrated? Should these two fields be integrated? And, if so, how is it best to integrate these two fields? Although this chapter touches on the logical and normative questions, it is the third, methodological question that receives the greatest attention. We argue that although, from a philosophical perspective, there are no methodological barriers to integrating these two subfields, there is a methodological bonanza in their integration. The golden opportunity is for integrative researchers to abandon a methodological exclusivism that privileges the research methods of the natural sciences in favor of a methodological pluralism that critically engages the philosophical schools and religious/spiritual traditions within which features of human well-being and religious/spiritual life are located. This more eclectic epistemology will provide a broader evidential basis for integrative conclusions and will help connect those conclusions to the realities and complexities of human lives
Localization of Quaternary slip rates in an active rift in 10(5) years: an example from central Greece constrained by U-234-Th-230 coral dates from uplifted paleoshorelines
Mapping, dating, and modeling of paleoshorelines uplifted in the footwall of the 1981 Gulf of Corinth earthquake fault, Greece (Ms 6.9–6.7), are used to assess its slip rate history relative to other normal faults in the area and study strain localization. The 234U-230Th coral ages from Cladocora caespitosa date uplifted shoreface sediments, and paleoshorelines from glacioeustatic sea level highstands at 76, (possibly) 100, 125, 175, 200, 216, 240, and 340 ka. Uplifted Quaternary and Holocene paleoshorelines decrease in elevation toward the western tip of the fault, exhibiting larger tilt angles with age, showing that uplift is due to progressive fault slip. Since 125 ka, uplift rates varied from 0.25 to 0.52 mm/yr over a distance of 5 km away from the fault tip. Tilting was also occurring prior to 125 ka, but uplift rates were lower because the 125 ka paleoshoreline is at 77% of the elevation of the 240 ka paleoshoreline despite being nearly half its age. Comparison of paleoshoreline elevations and sedimentology with the Quaternary sea level curve shows that slip rates increased by a factor of 3.2 ± 0.2 at 175 ± 75 ka, synchronous with cessation of activity on a neighboring normal fault at 382–112 ka. We suggest that the rapid localization of up to 10–15 mm/yr of extension into the narrow gulf (∼30 km wide) resulted from synchronous fault activity on neighboring faults followed by localization rather than sequential faulting, with consequences for the mechanism controlling localization of extension
The quantum structure of spacetime at the Planck scale and quantum fields
We propose uncertainty relations for the different coordinates of spacetime
events, motivated by Heisenberg's principle and by Einstein's theory of
classical gravity. A model of Quantum Spacetime is then discussed where the
commutation relations exactly implement our uncertainty relations.
We outline the definition of free fields and interactions over QST and take
the first steps to adapting the usual perturbation theory. The quantum nature
of the underlying spacetime replaces a local interaction by a specific nonlocal
effective interaction in the ordinary Minkowski space. A detailed study of
interacting QFT and of the smoothing of ultraviolet divergences is deferred to
a subsequent paper.
In the classical limit where the Planck length goes to zero, our Quantum
Spacetime reduces to the ordinary Minkowski space times a two component space
whose components are homeomorphic to the tangent bundle TS^2 of the 2-sphere.
The relations with Connes' theory of the standard model will be studied
elsewhere.Comment: TeX, 37 pages. Since recent and forthcoming articles (hep-th/0105251,
hep-th/0201222, hep-th/0301100) are based on this paper, we thought it would
be convenient for the readers to have it available on the we
Path and Path Deviation Equations for p-branes
Path and path deviation equations for neutral, charged, spinning and spinning
charged test particles, using a modified Bazanski Lagrangian, are derived. We
extend this approach to strings and branes. We show how the Bazanski Lagrangian
for charged point particles and charged branes arises `a la Kaluza-Klein from
the Bazanski Lagrangian in 5-dimensions.Comment: 13 pages, LaTeX fil
Dynamic depletion in a Bose condensate via a sudden increase of the scattering length
We examine the time-dependent quantum depletion of a trapped Bose condensate
arising from a rapid increase of the scattering length. Our solution indicates
that a significant buildup of incoherent atoms can occur within a
characteristic time short compared with the harmonic trap period. We discuss
how the depletion density and the characteristic time depend on the physical
parameters of the condensate
Characterization of elastic scattering near a Feshbach resonance in rubidium 87
The s-wave scattering length for elastic collisions between 87Rb atoms in the
state |f,m_f>=|1,1> is measured in the vicinity of a Feshbach resonance near
1007 G. Experimentally, the scattering length is determined from the mean-field
driven expansion of a Bose-Einstein condensate in a homogeneous magnetic field.
The scattering length is measured as a function of the magnetic field and
agrees with the theoretical expectation. The position and the width of the
resonance are determined to be 1007.40 G and 0.20 G, respectively.Comment: 4 pages, 2 figures minor revisions: added Ref.6, included error bar
Finite temperature scaling theory for the collapse of Bose-Einstein condensate
We show how to apply the scaling theory in an inhomogeneous system like
harmonically trapped Bose condensate at finite temperatures. We calculate the
temperature dependence of the critical number of particles by a scaling theory
within the Hartree-Fock approximation and find that there is a dramatic
increase in the critical number of particles as the condensation point is
approached.Comment: Published online [6 pages, 3 figures
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