252 research outputs found
Uncertainty budget of a large-range nanopositioning platform based on Monte Carlo simulation
The objective of precision systems design is to obtain machines with very high and totally predictable work-zone accuracies. In already functional systems, where the errors can be measured, this is achieved by error correction and compensation. The aim of this work is to propose an uncertainty budget methodology to obtain the final measuring uncertainty of precise measuring systems, after error compensation. The case study is a nanopositioning platform, referred as NanoPla, with a confocal sensor integrated as measuring instrument. The NanoPla performs precise positioning in a large range of 50 mm × 50 mm, and its target is surface topography characterization, at a submicrometre scale. After performing the uncertainty budget of the NanoPla, Monte Carlo method is used to obtain the final measuring uncertainty along the whole NanoPla working range, considering all the casuistry. By studying the results, the authors are able to propose solutions to minimize the final measuring uncertainty
In vitro degradation and mechanical properties of PLA-PCL copolymer unit cell scaffolds generated by two-photon polymerization
The manufacture of 3D scaffolds with specific controlled porous architecture, defined microstructure and an adjustable degradation profile was achieved using two-photon polymerization (TPP) with a size of 2 × 4 × 2 mm3. Scaffolds made from poly(D,L-lactide-co-ε-caprolactone) copolymer with varying lactic acid (LA) and ε -caprolactone (CL) ratios (LC16:4, 18:2 and 9:1) were generated via ring-opening-polymerization and photoactivation. The reactivity was quantified using photo-DSC, yielding a double bond conversion ranging from 70% to 90%. The pore sizes for all LC scaffolds were see 300 μm and throat sizes varied from 152 to 177 μm. In vitro degradation was conducted at different temperatures; 37, 50 and 65°C. Change in compressive properties immersed at 37°C over time was also measured. Variations in thermal, degradation and mechanical properties of the LC scaffolds were related to the LA/CL ratio. Scaffold LC16:4 showed significantly lower glass transition temperature (T g) (4.8°C) in comparison with the LC 18:2 and 9:1 (see 32°C). Rates of mass loss for the LC16:4 scaffolds at all temperatures were significantly lower than that for LC18:2 and 9:1. The degradation activation energies for scaffold materials ranged from 82.7 to 94.9 kJ mol-1. A prediction for degradation time was applied through a correlation between long-term degradation studies at 37°C and short-term studies at elevated temperatures (50 and 65°C) using the half-life of mass loss (Time (M1/2)) parameter. However, the initial compressive moduli for LC18:2 and 9:1 scaffolds were 7 to 14 times higher than LC16:4 (see 0.27) which was suggested to be due to its higher CL content (20%). All scaffolds showed a gradual loss in their compressive strength and modulus over time as a result of progressive mass loss over time. The manufacturing process utilized and the scaffolds produced have potential for use in tissue engineering and regenerative medicine applications
Isolation of a novel aquaglyceroporin from a marine teleost (Sparus auratus) Function and tissue distribution
The aquaporins (formerly called the major intrinsic
protein family) are transmembrane channel proteins. The
family includes the CHIP group, which are functionally
characterised as water channels and the GLP group,
which are specialised for glycerol transport. The present
study reports the identification and characterisation of a
novel GLP family member in a teleost fish, the sea bream
Sparus auratus. A sea bream aquaporin (sbAQP) cDNA of
1047·bp and encoding a protein of 298·amino acids was
isolated from a kidney cDNA library. Functional
characterization of the sbAQP using a Xenopus oocyte
assay revealed that the isolated cDNA stimulated osmotic
water permeability in a mercury-sensitive manner and
also stimulated urea and glycerol uptake. Northern
blotting demonstrated that sbAQP was expressed at high
levels in the posterior region of the gut, where two transcripts were identified (1.6·kb and 2·kb), and in
kidney, where a single transcript was present (2·kb). In
situ hybridisation studies with a sbAQP riboprobe
revealed its presence in the lamina propria and smooth
muscle layer of the posterior region of the gut and in
epithelial cells of some kidney tubules. sbAQP was also
present in putative chloride cells of the gill. Phylogenetic
analysis of sbAQP, including putative GLP genes from
Fugu rubripes, revealed that it did not group with any of
the previously isolated vertebrate GLPs and instead
formed a separate group, suggesting that it may be a novel
GLP member.This work was supported by project PRAXIS
XXI/2/2.1/BIA/211/94 from the Portuguese National Science
and Technology Foundation (FCT), co-financed by EU
structural funds, DG-Fisheries Project Q5RS-2002-00784
(CRYOCYTE) and an EU Biotech grant (QLRT2000-00778).
C.R.A.S., J.C.R.C. and J.F. were in receipt of FCT
fellowships PRAXIS XXI/BPD/22040/99, PRAXIS
XXI/BD/19925/99BPD/22033/99, respectively
Linking data and BPMN processes to achieve executable models
We describe a formally well founded approach to link data and processes conceptually, based on adopting UML class diagrams to represent data, and BPMN to represent the process. The UML class diagram together with a set of additional process variables, called Artifact, form the information model of the process. All activities of the BPMN process refer to such an information model by means of OCL operation contracts. We show that the resulting semantics while abstract is fully executable. We also provide an implementation of the executor.Peer ReviewedPostprint (author's final draft
Ancient and modern mitogenomes from Central Argentina: New insights into population continuity, temporal depth and migration in South America
The inverted triangle shape of South America places Argentina territory as a geographical crossroads between the two principal peopling streams that followed either the Pacific or the Atlantic coasts, which could have then merged in Central Argentina (CA). Although the genetic diversity from this region is therefore crucial to decipher past population movements in South America, its characterization has been overlooked so far. We report 92 modern and 22 ancient mitogenomes spanning a temporal range of 5000 years, which were compared with a large set of previously reported data. Leveraging this dataset representative of the mitochondrial diversity of the subcontinent, we investigate the maternal history of CA populations within a wider geographical context. We describe a large number of novel clades within the mitochondrial DNA tree, thus providing new phylogenetic interpretations for South America. We also identify several local clades of great temporal depth with continuity until the present time, which stem directly from the founder haplotypes, suggesting that they originated in the region and expanded from there. Moreover, the presence of lineages characteristic of other South American regions reveals the existence of gene flow to CA. Finally, we report some lineages with discontinuous distribution across the Americas, which suggest the persistence of relic lineages likely linked to the first population arrivals. The present study represents to date the most exhaustive attempt to elaborate a Native American genetic map from modern and ancient complete mitochondrial genomes in Argentina and provides relevant information about the general process of settlement in South America.This work was supported by Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación (PICT 2007-1549, PICT 2012-711 and PICT 2015-3155), Secretaría de Ciencia y Tecnología (Universidad Nacional de Córdoba), Ministerio de Ciencia y Tecnología de la Provincia de Córdoba (PID 2018-79) and Consejo Nacional de Investigaciones Científicas y Técnicas (2015-11220150100953CO). M.P. is a postdoctoral fellow and A.G., R.N., J.M.B.M, C.M.B., M.F. and D.A.D. are research career members of CONICET, Argentina
Layer-by-layer technique to developing functional nanolaminate films with antifungal activity
The layer-by-layer (LbL) deposition method was used to build up alternating layers (five) of different polyelectrolyte solutions (alginate, zein-carvacrol nanocapsules, chitosan and chitosan-carvacrol emulsions) on an aminolysed/charged polyethylene terephthalate (A/C PET) film. These nanolaminated films were characterised by contact angle measurements and through the determination of water vapour (WVTR) and oxygen (O2TR) transmission rates. The effect of active nanolaminated films against the Alternaria sp. and Rhizopus stolonifer was also evaluated. This procedure allowed developing optically transparent nanolaminated films with tuneable water vapour and gas properties and antifungal activity. The water and oxygen transmission rate values for the multilayer films were lower than those previously reported for the neat alginate or chitosan films. The presence of carvacrol and zein nanocapsules significantly decreased the water transmission rate (up to 40 %) of the nanolaminated films. However, the O2TR behaved differently and was only improved (up to 45 %) when carvacrol was encapsulated, i.e. nanolaminated films prepared by alternating alginate with nanocapsules of zein-carvacrol layers showed better oxygen barrier properties than those prepared as an emulsion of chitosan and carvacrol. These films containing zein-carvacrol nanocapsules also showed the highest antifungal activity (30 %), which did not significantly differ from those obtained with the highest amount of carvacrol, probably due to the controlled release of the active agent (carvacrol) from the zein-carvacrol nanocapsules. Thus, this work shows that nanolaminated films prepared with alternating layers of alginate and zein-carvacrol nanocapsules can be considered to improve the shelf-life of foodstuffs.The authors acknowledge financial support from
FP7 IP project BECOBIOCAP^. M. J. Fabra is recipients of a Juan de la
Cierva contract from the Spanish Ministry of Economy and
Competitivity. Maria L. Flores-López thanks Mexican Science and Technology
Council (CONACyT, Mexico) for PhD fellowship support
(CONACyT Grant Number 215499/310847). The author Miguel A.
Cerqueira is a recipient of a fellowship (SFRH/BPD/72753/2010) supported
by Fundação para a Ciência e Tecnologia, POPH-QREN and FSE
(FCT, Portugal). The authors also thank the FCT Strategic Project of UID/
BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-
01-0124-FEDER-027462) and the project BBioInd - Biotechnology and
Bioengineering for improved Industrial and Agro-Food processes,^ REF.
NORTE-07-0124-FEDER-000028 Co-funded by the Programa
Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER.
The support of EU Cost Action FA0904 is gratefully acknowledged
Efecto de bacterias biocontroladoras sobre Thecaphora frezii bajo dos situaciones con diferente potencial inoculo
Resumen extendidoEn los últimos años diversas empresas e instituciones trabajan en el desarrollo de técnicas de control y manejo de enfermedades utilizando agentes biológicos que sean eficaces y de bajo impacto ambiental. En el caso del carbón del maní (Thecaphora frezii) se han probado diferentes métodos de control y uno de ellos es el biocontrol que podría representar una alternativa para el manejo de la enfermedad, debido a que el uso de hongos y bacterias como mitigantes del complejo de patógenos que afectan a los cultivos, viene cobrando importancia en el sistema manisero de la provincia de Córdoba. En este trabajo se planteó como objetivo evaluar el efecto de la aplicación de bacterias biocontroladoras sobre la intensidad final de carbón del maní en dos situaciones con diferencias importantes en el potencial inóculo de cada suelo.Centro de Investigaciones AgropecuariasFil: Kearney, M. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Biología Agrícola; ArgentinaFil: Zuza, M. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Biología Agrícola; ArgentinaFil: Peralta, V. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Biología Agrícola; ArgentinaFil: Figueredo, M.S. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Pérez, A. Fundación Maní Argentina; ArgentinaFil: Rago, Alejandro Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones Agropecuarias (CIAP); ArgentinaFil: Rago, Alejandro Mario. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Biología Agrícola; ArgentinaFil: Tonelli, L. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Fabra, A. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; Argentin
Properties of biopolymer dispersions and films used as carriers of the biocontrol agent Candida sake CPA-1
[EN] The use of biocontrol agents (BCA) for controlling plant diseases is an alternative to reduce the use of
pesticides. Their performance can be improved when applied in combination with coatings. Films and
coatings formulated from different biopolymers were characterized as to their barrier and optical
properties to analyse their impact on fruit when applied as carriers of the BCA Candida sake CPA-1. The
properties of the film-forming dispersions were more affected by the type of polymer than by the
incorporation of surfactants. Sodium caseinate formed the thickest coatings, but these were very thin in
every case, which led to there being no predicted relevant effect on the gas exchanges of the fruit. The
cell viability in the films was good during film drying, especially in the case of protein films; however, it
decreased after storage.The authors are grateful to the Spanish Government for the financial support through project RTA2012-00067-0O2 and to the Conselleria d'Educacio of the Generalitat Valenciana, (Spain) for A. Marin's PhD grant (VALi+d 2013). The authors are also thankful to IRTA group, headed by Dra. Neus Teixido, for their assistance in the microbiological study.Marín-Gozalbo, A.; Atarés Huerta, LM.; Cháfer Nácher, MT.; Chiralt, A. (2017). Properties of biopolymer dispersions and films used as carriers of the biocontrol agent Candida sake CPA-1. LWT - Food Science and Technology. 79:60-69. https://doi.org/10.1016/j.lwt.2017.01.024S60697
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