347 research outputs found
Viticultural Climate Indexes and Their Role in The Prediction of Anthocyanins and Other Flavonoids Content in Seedless Table Grapes
Background: Viticulture bioclimatic indexes like the Heliothermal Index (HI), Cool Night
Index (CI), and Dryness Index (DI), can be used to assess the influence of climate on grapesâ quality.
Methods: HI, CI, and DI + total seasonal irrigation were utilized to assess the effect of climate on
the flavonoids content and composition of two Vitis vinifera seedless varieties, âSummer Royalâ and
âCrimson Seedlessâ, both grown in Apulia (Southern Italy). Results: The flavonoids content was
significantly affected by variety and climate conditions on the base of HI, CI, and DI + total seasonal
irrigation. Factor analysis applied to climate indexes and flavonoids showed that anthocyanins and
flavonols were negatively and positively correlated to CI in both varieties, respectively. Additionally,
warmer night temperatures determined higher fla-van-3-ols. HI increase promoted anthocyanins,
flavonols, and flavan-3-ols content in Crimson Seedless, whilst it induced an opposite trend in
Summer Royal. Finally, DI + total seasonal irrigation showed to be positively linked to flavonols
content and negatively linked to anthocyanins content just in the case of Crimson Seedless. Significant
regression models were also determined between climate indexes and productive parameters (i.e.,
yield, TSS, TA, pH, bunch, and berry weight). Conclusions: Climate indexes HI, CI, and DI + total
seasonal irrigation showed an effect on quality grape parameters like flavonoids and contributed to
building predictive models when new climatic zones are going to be evaluated for the production of
table grapes
Images in Christmas Balls
We describe light-reflection properties of spherically curved mirrors, like
balls in the Christmas tree. In particular, we study the position of the image
which is formed somewhere beyond the surface of a spherical mirror, when an eye
observes the image of a pointlike light source. The considered problem,
originally posed by Abu Ali Hasan Ibn al-Haitham -- alias Alhazen -- more than
a millennium ago, turned out to have the now well known analytic solution of a
biquadratic equation, being still of great relevance, e.g. for the
aberration-free construction of telescopes. We do not attempt to perform an
exhaustive survey of the rich historical and engineering literature on the
subject, but develop a simple pedagogical approach to the issue, which we
believe to be of continuing interest in view of its maltreating in many
high-school textbooks.Comment: 13 pages, 7 figures plain LaTeX; Also see
http://cft.fis.uc.pt/eef/mirrors.htm, revised version has simplified
formulas, more transparent for a wider audience, one reference adde
A small organic compound enhances the religation reaction of human topoisomerase I and identifies crucial elements for the religation mechanism
The different steps of the human Top1 (topoisomerase I) catalytic cycle have been analysed in the presence of a
pentacyclic-diquinoid synthetic compound. The experiments indicate that it efficiently inhibits the cleavage step of
the enzyme reaction, fitting well into the catalytic site. Surprisingly the compound, when incubated with the binary
topoisomeraseâDNA cleaved complex, helps the enzyme to remove itself from the cleaved DNA and close the DNA gap,
increasing the religation rate. The compound also induces the religation of the stalled enzymeâCPT (camptothecin)â
DNA ternary complex. Analysis of the molecule docked over the binary complex, together with its chemical properties,
suggests that the religation enhancement is due to the presence on the compound of two oxygen atoms that act as
hydrogen acceptors. This property facilitates the deprotonation of the 5 DNA end, suggesting that this is the limiting
step in the topoisomerase religation mechanism
BeppoSAX Detection and Follow-up of GRB980425
We present BeppoSAX GRBM and WFC light curves of GRB980425 and NFI follow-up
data taken in 1998 April, May, and November. The first NFI observation has
detected within the 8' radius error box of the GRB an X-ray source positionally
consistent with the supernova SN 1998bw, exploded within a day of GRB980425,
and a fainter X-ray source, not consistent with the position of the supernova.
The former source is detected in the following NFI pointings and exhibits a
decline of a factor of two in six months. If it is associated with SN 1998bw,
this is the first detection of hard X-ray emission from a Type I supernova. The
latter source exhibits only marginally significant variability. Based on these
data, it is not possible to select either source as a firm candidate for the
GRB counterpart.Comment: 2 pages, 1 PostScript figure, submitted to A&AS, Proc. of the
Conference "Gamma-Ray Bursts in the Afterglow Era", held in Rome, 1998
November 3-6. Results concerning 'Source 2' have been update
Bone regeneration mediated by a bioactive and biodegradable ECM-like hydrogel based on elastin-like recombinamers
ProducciĂłn CientĂficaThe morbidity of bone fractures and defects is steadily increasing due to changes in the age pyramid. As such, novel biomaterials that are able to promote the healing and regeneration of injured bones are needed in order to overcome the limitations of auto-, allo-, and xenografts, while providing a ready-to-use product that may help to minimize surgical invasiveness and duration. In this regard, recombinant biomaterials, such as elastin-like recombinamers (ELRs), are very promising as their design can be tailored by genetic engineering, thus allowing scalable production and batch-to-batch consistency, amongst others. Furthermore, they can self-assemble into physically cross-linked hydrogels above a certain transition temperature, in this case body temperature, but are injectable below this temperature, thereby markedly reducing surgical invasiveness. Herein we have developed two bioactive hydrogel-forming ELRs, one including the osteogenic and osteoinductive BMP-2 and the other the RGD cell-adhesion motif. The combination of these two novel ELRs results in a BMP-2-loaded extracellular matrix-like hydrogel. Moreover, elastase-sensitive domains were included in both ELR molecules, thereby conferring biodegradation as a result of enzymatic cleavage and avoiding the need for scaffold removal after bone regeneration. Both ELRs and their combination showed excellent cytocompatibility, and the culture of cells on RGD-containing ELRs resulted in optimal cell adhesion. In addition, hydrogels based on a mixture of both ELRs were implanted in a pilot study involving a femoral bone injury model in New Zealand White rabbits, showing complete regeneration in six out of seven cases, with the other showing partial closure of the defect. Moreover, bone neo-formation was confirmed using different techniques, such as radiography, computed tomography and histology. This hydrogel system therefore displays significant potential in the regeneration of bone defects, promoting self-regeneration by the surrounding tissue with no involvement of stem cells or osteogenic factors other than BMP-2, which is released in a controlled manner by elastase-mediated cleavage from the ELR backbone.Ministerio de EconomĂa, Industria y Competitividad (Project (MAT2013-42473-R and MAT2013-41723-R)Junta de Castilla y LeĂłn (programa de apoyo a proyectos de investigaciĂłn â Ref. VA244U13 and VA313U14)Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y LeĂłnComisiĂłn Europea (proyectos NMP-2014-646075, HEALTH-F4-2011-278557, PITN-GA-2012-317306 y MSCA-ITN-2014-642687
BeppoSAX Observations of GRB980425: Detection of the Prompt Event and Monitoring of the Error Box
We present BeppoSAX follow-up observations of GRB980425 obtained with the
Narrow Field Instruments (NFI) in April, May, and November 1998. The first NFI
observation has detected within the 8' radius error box of the GRB an X-ray
source positionally consistent with the supernova 1998bw, which exploded within
a day of GRB980425, and a fainter X-ray source, not consistent with the
position of the supernova. The former source is detected in the following NFI
pointings and exhibits a decline of a factor of two in six months. If it is
associated with SN 1998bw, this is the first detection of X-ray emission from a
Type I supernova above 2 keV. The latter source exhibits only marginally
significant variability. The X-ray spectra and variability of the supernova are
compared with thermal and non-thermal models of supernova high energy emission.
Based on the BeppoSAX data, it is not possible to firmly establish which of the
two detected sources is the GRB X-ray counterpart, although probability
considerations favor the supernova.Comment: 16 pages, Latex, 6 PostScript figures and 1 GIF figure, 2 tables,
submitted to The Astrophysical Journa
Integrative analysis to select cancer candidate biomarkers to targeted validation
FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOTargeted proteomics has flourished as the method of choice for prospecting for and validating potential candidate biomarkers in many diseases. However, challenges still remain due to the lack of standardized routines that can prioritize a limited number of proteins to be further validated in human samples. To help researchers identify candidate biomarkers that best characterize their samples under study, a well-designed integrative analysis pipeline, comprising MS-based discovery, feature selection methods, clustering techniques, bioinformatic analyses and targeted approaches was performed using discovery-based proteomic data from the secretomes of three classes of human cell lines (carcinoma, melanoma and non-cancerous). Three feature selection algorithms, namely, Beta-binomial, Nearest Shrunken Centroids (NSC), and Support Vector Machine-Recursive Features Elimination (SVM-RFE), indicated a panel of 137 candidate biomarkers for carcinoma and 271 for melanoma, which were differentially abundant between the tumor classes. We further tested the strength of the pipeline in selecting candidate biomarkers by immunoblotting, human tissue microarrays, label-free targeted MS and functional experiments. In conclusion, the proposed integrative analysis was able to pre-qualify and prioritize candidate biomarkers from discovery-based proteomics to targeted MS.Targeted proteomics has flourished as the method of choice for prospecting for and validating potential candidate biomarkers in many diseases. However, challenges still remain due to the lack of standardized routines that can prioritize a limited number of proteins to be further validated in human samples. To help researchers identify candidate biomarkers that best characterize their samples under study, a well-designed integrative analysis pipeline, comprising MS-based discovery, feature selection methods, clustering techniques, bioinformatic analyses and targeted approaches was performed using discovery-based proteomic data from the secretomes of three classes of human cell lines (carcinoma, melanoma and non-cancerous). Three feature selection algorithms, namely, Beta-binomial, Nearest Shrunken Centroids (NSC), and Support Vector Machine-Recursive Features Elimination (SVM-RFE), indicated a panel of 137 candidate biomarkers for carcinoma and 271 for melanoma, which were differentially abundant between the tumor classes. We further tested the strength of the pipeline in selecting candidate biomarkers by immunoblotting, human tissue microarrays, label-free targeted MS and functional experiments. In conclusion, the proposed integrative analysis was able to pre-qualify and prioritize candidate biomarkers from discovery-based proteomics to targeted MS6414363543652FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOFAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO2009/54067-3; 2010/19278-0; 2011/22421-2; 2009/53839-2470567/2009-0; 470549/2011-4; 301702/2011-0; 470268/2013-
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