256 research outputs found
Bacterial outer membrane vesicles and vaccine applications
Vaccines based on outer membrane vesicles (OMV) were developed more than 20 years ago against Neisseria meningitidis serogroup B. These nano-sized structures exhibit remarkable potential for immunomodulation of immune responses and delivery of âselfâ meningococcal antigens or unrelated antigens incorporated into the vesicle structure. This paper reviews different applications in OMV Research and Development (R&D) and provides examples of OMV developed and evaluated at the Finlay Institute in Cuba. A Good Manufacturing Practice (GMP) process was developed at the Finlay Institute to produce OMV from N. meningitidis serogroup B (dOMVB) using detergent extraction. Subsequently, OMV from N. meningitidis, serogroup A (dOMVA), serogroup W (dOMVW) and serogroup X (dOMVX) were obtained using this process. More recently, the extraction process has also been applied effectively for obtaining OMV on a research scale from Vibrio cholerae (dOMVC), Bordetella pertussis (dOMVBP), Mycobacterium smegmatis (dOMVSM) and BCG (dOMVBCG). The immunogenicity of the OMV have been evaluated for specific antibody induction, and together with functional bactericidal and challenge assays in mice have shown their protective potential. dOMVB has been evaluated with non-self neisserial antigens, including with a herpes virus type 2 glycoprotein, ovalbumin and allergens. In conclusion, OMV are proving to be more versatile than first conceived and remain an important technology for development of vaccine candidates. - See more at: http://journal.frontiersin.org/Journal/10.3389/fimmu.2014.00121/abstract#sthash.MwqUyZQ1.dpu
A two-dimensional Dirac fermion microscope
The electron microscope has been a powerful, highly versatile workhorse in
the fields of material and surface science, micro and nanotechnology, biology
and geology, for nearly 80 years. The advent of two-dimensional materials opens
new possibilities for realising an analogy to electron microscopy in the solid
state. Here we provide a perspective view on how a two-dimensional (2D) Dirac
fermion-based microscope can be realistically implemented and operated, using
graphene as a vacuum chamber for ballistic electrons. We use semiclassical
simulations to propose concrete architectures and design rules of 2D electron
guns, deflectors, tunable lenses and various detectors. The simulations show
how simple objects can be imaged with well-controlled and collimated in-plane
beams consisting of relativistic charge carriers. Finally, we discuss the
potential of such microscopes for investigating edges, terminations and
defects, as well as interfaces, including external nanoscale structures such as
adsorbed molecules, nanoparticles or quantum dots.Comment: 34 pages; 14 pages; 6 figures; Supplementary informatio
New insights into evaluation of regression models through a decomposition of the prediction errors : application to near-infrared spectral data
This paper analyzes the performance of linear regression models taking into account usual criteria such as the number of principal components or latent factors, the goodness of fit or the predictive capability. Other comparison criteria, more common in an economic context, are also considered: the degree of multicollinearity and a decomposition of the mean squared error of the prediction which determines the nature, systematic or random, of the prediction errors. The applications use real data of extra-virgin oil obtained by near-infrared spectroscopy. The high dimensionality of the data is reduced by applying principal component analysis and partial least squares analysis. A possible improvement of these methods by using cluster analysis or the information of the relative maxima of the spectrum is investigated. Finally, obtained results are generalized via cross- validation and bootstrapping
Characteristics of vineyard soils derived from Plio-Quaternary landforms (raña or rañizo) in southern Europe
Soil is an essential component in viticulture. The study reported here concerns
the assessment of the morphology chemical and physicochemical features of
typical, well-developed and representative evolved Mediterranean soils near
Anchuras (Spain, southern Europe), a site with soils that developed on old
landforms (Plio-Quaternary) called ârañaâ and/or ârañizoâ. The soils under
study were described and sampled by conducting soil surveys. Selected soil
properties, such as texture, bulk density, pH, electrical conductivity (EC), cation exchange capacity (CEC) and contents of organic matter, nutrients, etc.,
were analysed using standard procedures. The results showed that these landscape surfaces were, linked with specific soil properties such as low pH (from
4.4 to 5.3) and EC (from 0.15 to 0.02 dSm 1
), clay contents (20.1%â48.8%), high
CEC (26â39 cmol/kg), and low base saturation values (from 11.2% to 17.2%),
and have an adequate and singular pedological potential in relation to the âterroirâ or âterronâ concepts that meet suitability criteria. Furthermore, the information provided by this study, fundamentally through the weathering indices,
supports the role of soil-forming factors and their influence on soil properties.
In addition, as these landforms and underlying materials have abundant and
extensive rock fragments, the role of these soils in the context of vineyard
growth and development has been investigatedThis research was supported by the Winerin Eldoze (Project
number UCTR180065
A morphological approach to evaluating the nature of vineyard soils in semiarid Mediterranean environment
La Mancha (Central Spain) is one of the most extensive vineyard regions in the world, and âValdepeñasâ is a representative Protected Denomination of Origin (PDO) in this region. However, what are their main soil types? what kind of horizons are the most common? and what is the role of the geomorphological positions in their pedodiversity? After describing and sampling 90 soil profiles in this area, Alfisols, Inceptisols and Entisols were mainly identified in Soil Taxonomy terms; in other words, Luvisols, Cambisols, Regosols, Leptosols and a highly significant proportion of Calcisols according to FAO-UNESCO-ISSS. The accumulation of carbonate, the thickness of which varies from a diffuse or powdery form to crusted forms, appear sometimes like polycyclic. The presence of red soils, with or without a calcic or petrocalcic horizon, indicates the most representative edaphic stages in this region. Consequently, the morphological signature is calcic or petrocalcic, followed by argillic and/or cambic horizons, under ochric horizons. It can be concluded that the nature of soils in Valdepeñas can be considered a differential factor to bear in mind for quality viticultural production. Highlights: There are unknown conceptual zones in support production of wine. A comprehensive study in a local case was performed due to its traditional production of vineyards. This study highlights the importance and uniqueness of the calcic and petrocalcic horizons. A disconnect exists between some tradicional viticultural zones with low reputation and the real value of their soil
Gate electrostatics and quantum capacitance in ballistic graphene device
We experimentally investigate the charge induction mechanism across gated,
narrow, ballistic graphene devices with different degrees of edge disorder. By
using magnetoconductance measurements as the probing technique, we demonstrate
that devices with large edge disorder exhibit a nearly homogeneous capacitance
profile across the device channel, close to the case of an infinitely large
graphene sheet. In contrast, devices with lower edge disorder (< 1 nm
roughness) are strongly influenced by the fringing electrostatic field at
graphene boundaries, in quantitative agreement with theoretical calculations
for pristine systems. Specifically, devices with low edge disorder present a
large effective capacitance variation across the device channel with a
nontrivial, inhomogeneous profile due not only to classical electrostatics but
also to quantum mechanical effects. We show that such quantum capacitance
contribution, occurring due to the low density of states (DOS) across the
device in the presence of an external magnetic field, is considerably altered
as a result of the gate electrostatics in the ballistic graphene device. Our
conclusions can be extended to any two dimensional (2D) electronic system
confined by a hard-wall potential and are important for understanding the
electronic structure and device applications of conducting 2D materials.Comment: 3 figure
High quality sub-10 nm graphene nanoribbons by on-chip PS-b-PDMS block copolymer lithography
âHigh quality sub-10 nm graphene nanoribbons by on-chip PS-b-PDMS block copolymer lithographyâ, SEM image of sub-10 nm graphene nanoribbons fabricated using a brushless lamellar PS-b-PDMS (5kâ5.5k) block copolymer and its Raman spectra.</p
Racism: A Teenagers\u27 Perspective Results of Preliminary Research from Madrid, Spain
In mid-June, 2005, the members of the INTER Center received a collaboration proposal from FETE-UGT8, with the objective of carrying out a brief exploratory study on the perceptions and experiences that young people and adolescents, mainly immigrants, have concerning possible experiences of discrimination and racism in their immediate surroundings.
The initial objectives of the project were expanded due to the dynamics of the project itself. New focuses of attention and social, educational and personal dynamics, which can condition to a certain extent the experiences that immigrant adolescents undergo, were detected.
The project initially consisted of a series of interviews with adolescents between 12 and 18 years of age. A total of 20 interviews were carried out, some of them group interviews. We consider this project focus, although positive, to be limited, and we think that it would have been necessary to broaden the sample and consider other people in the young peopleâs social and family environment (family members, friends, classmates, professors, all of them of different origins, including the host country)
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