29 research outputs found
Analysis of the expression of S alleles in "Rocha" pear
Analysis of the expression of S alleles in âRochaâ pear. In this work, the
expression of incompatibility genes (S-alleles) in âRochaâ pear was investigated. The
comparison of these alleles with the alleles of other cultivars may constitute a tool to
help the technicians and farmers to choose pollinators when planning a new âRochaâ
orchard. We have used molecular techniques that include pistil RNA extraction from
three clones of cultivar âRochaâ (R1, R2 and R4C), fragment amplification by RT-PCR,
cloning and sequencing. The flowers utilized to extract RNA were isolated before
anthesis to guarantee the absence of pollen from other cultivars in their pistils, which
could interfere with the rejection process of the auto-pollen. Analysing the genetic
sequences obtained from the three clones, no differences between clones were
detectable and the sequences corresponded to Sj and Sa alleles. âRochaâ pear is semicompatible
with cultivars which do not present Sj or Sa, totally incompatible with
cultivars that carry Sj and Sa, and totally compatible with cultivars that do not carry Sj
and Sa
Identification of S alleles of different pear cultivars of the "Oeste" region and evaluation of their gametophytic compatibility with 'Rocha' pear
In order to select pear cultivar which are genetically compatible with âRochaâ (Sa, Sj), the identification
of S alleles sequences of commercial cultivars with bloom periods overlapping
(partially or totally) the bloom period of âRochaâ was performed. Partial sequences of
the S alleles from the different cultivars were amplified with specific primers, cloned
and sequenced. âPĂȘra De Ăguaâ (S22, Sb) âGĂ©nĂ©ral Leclercâ (Sl, Sq) and âAlexandrine
Douillardâ (Sb, Sk) should be totally compatible. It was identified a Sj allele in the
cultivars âAmĂȘndoaâ, âBeurrĂ© Precoce Morettiniâ, âClappâs Rougeâ e âClappâs
Favouriteâ and an allele Sa in âBeurrĂ© Clairgeauâ, indicating that these cultivars are
semi-compatible with âRochaâ. âCarapinheiraâ (Sb) and âPĂ©rolaâ (Sk) carry a different
allele from the ones of âRochaâ and an amplification pattern completely dissimilar
suggesting full compatibility. In âPasse Crassaneâ (Sr) and âBeurrĂ© DâAvrilâ (S4), a
different allele from the S alleles of âRochaâ was identified indicating compatibility, but
total or partial compatibility remained unclear, since the amplification pattern does not
exclude that the unknown allele might be Sa from âRochaâ
Optimization of filament antennas using the Gauss-Newton method
The project of the Yagi-Uda antenna was optimized using the Gauss-Newton method. The optimization consisted of specifying value interval for directivity, front-to-back ratio and beamwidth and, starting from a pre-defined initial model, the best values for the length and spacing of the elements were determined. For the direct modeling, the method of moments on the integral Pocklington equation was used, which consisted of obtaining the values of directivity, front-to-back ratio and beamwidth from the length and spacing between known elements. The procedure was applied to the synthesis of Yagi-Uda antennas with five and six elements and the results were found to be as good as those obtained in the literature using other optimization methods
Antioxidant power of small fruits and its beneficial effects to human health
The fruits as well as other organs of plants in its constitution have various
phytochemicals, including polyphenols, the antioxidant molecules highly abundant in
foods. Despite its ubiquity, its benefits to human health only start to be evaluated in
90âs, and it continues to reveal a growing interest, mainly due to epidemiological
studies suggesting a link between the consumption of food and beverages rich in
polyphenols and the reducing of the incidence and/or initiation of chronic and
degenerative diseases such as cardiovascular disease, atherosclerosis, and some cancers.
The investigation of its neuroprotective effects have being developed in the past 10
years, and it have been clearly demonstrated their ability to protect the cells either in
neuronal models in vitro and their in vivo intracellular effects.
A review of the evidences will be presented and in particular the work being
conducted in the laboratory of Disease and Stress Biology on the antioxidant power of berries such as wild blackberries, raspberry and strawberry tree fruit as well as their
leave
Antioxidant capacity of Macaronesian traditional medicinal plants
The use of many traditional medicinal plants is often hampered by the absence
of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized
ethnobotanical applications were analysed: Apollonias barbujana (Cav.) Bornm., Ocotea
foetens (Ainton) Baill, Prunus azorica (Mouill.) Rivas-Mart., LousĂŁ, Fern. Prieto, E. DĂas,
J.C. Costa & C. Aguiar, Rumex maderensis Lowe and Plantago arborescens Poir. subsp.
maderensis (Dcne.) A. Hans. et Kunk.. Since oxidative stress is a common feature of most
diseases traditionally treated by these plants, it is important to assess their antioxidant
capacity and determine the molecules responsible for this capacity. In this study, the
antioxidant capacity of these plants against two of the most important reactive species in
human body (hydroxyl and peroxyl radicals) was determined. To trace the antioxidant
origin total phenol and flavonoid contents as well as the polyphenolic profile and the
amount of trace elements were determined. There was a wide variation among the species
analysed in what concerns their total leaf phenol and flavonoid contents. From the High
Performance Liquid Chromatography (HPLC) electrochemically detected peaks it was
possible to attribute to flavonoids the antioxidant capacity detected in A. barbujana, O.
foetens, R. maderensis and P. azorica extracts. These potential reactive flavonoids were
identified for A. barbujana, R. maderensis and P. azorica. For R. maderensis a high
content (7 mg g-1 dry weight) of L-ascorbic acid, an already described antioxidant
phytomolecule, was found. A high content in selenomethionine (414.35 ÎŒg g-1 dry weight)
was obtained for P. arborescens subsp. maderensis extract. This selenocompound is
already described as a hydroxyl radical scavenger is reported in this work as also
possessing peroxyl radical scavenging capacity. This work is a good illustration of
different phytomolecules (flavonoids, organic acids and selenocompounds), presents in
leaves of the five traditional medicinal plants endemic to Macaronesia, all exhibiting
antioxidant propertiesinfo:eu-repo/semantics/publishedVersio
Neuroprotective effects of digested polyphenols from wild blackberry species
Abstract Purpose Blackberry ingestion has been demonstrated to attenuate brain degenerative processes with the benefits ascribed to the (poly)phenolic components. The aim of this work was to evaluate the neuroprotective potential of two wild blackberry species in a neurodegeneration cell model and compare them with a commercial variety. Methods This work encompasses chemical characterization before and after an in vitro digestion and the assessment of neuroprotection by digested metabolites. Some studies targeting redox/cell death systems were also performed to assess possible neuroprotective molecular mechanisms. Results The three blackberry extracts presented some quantitative differences in polyphenol composition that could be responsible for the different responses in the neurodegeneration cell model. Commercial blackberry extracts were ineffective but both wild blackberries, Rubus brigantinus and Rubus vagabundus, presented neuroprotective effects. It was verified that a diminishment of intracellular ROS levels, modulation of glutathione levels and activation of caspases occurred during treatment. The last effect suggests a preconditioning effect since caspase activation was not accompanied by diminution in cell death and loss of functionality. Conclusions This is the first time that metabolites obtained from an in vitro digested food matrix, and tested at levels approaching the concentrations found in human plasma, have been described as inducing an adaptative response
Comparison of different methods for DNA-free RNA isolation from SK-N-MC neuroblastoma
<p>Abstract</p> <p>Background</p> <p>RNA quality and quantity are important factors for ensuring the accuracy of gene expression analysis and other RNA-based downstream applications. Extraction of high quality nucleic acids is difficult from neuronal cells and brain tissues as they are particularly rich in lipids. In addition, most common RNA extraction methods are phenol-based, resulting in RNA that may be incompatible with downstream applications such as gene expression.</p> <p>Findings</p> <p>In this work, a comparative analysis of the RNA quality obtained from SK-N-MC cells was performed using six commonly used RNA isolation kits: two phenol-based kits and four non-phenol based kits. The non-phenol based kits tested AxyPrep Multisource Total RNA Miniprep, RNeasy<sup>Âź </sup>Mini, EasySpin and Ilustra RNAspin Mini RNA Isolation, all performed well and resulted in the isolation of high quality RNA, as evaluated by A<sub>260</sub>/A<sub>280</sub>. The RNA extracted with AxyPrep Multisource Total RNA Miniprep, RNeasy<sup>Âź </sup>Mini and EasySpin provided the highest RNA yields. In particular, the RNA isolated by AxyPrep Multisource Total RNA Miniprep Kit did not show any detectable genomic DNA contamination even without previous DNase treatment or after RNA direct PCR amplification using universal 18S primers.</p> <p>Conclusions</p> <p>The RNA extracted from SK-N-MC cells with AxyPrep Multisource Total RNA Miniprep Kit was superior with respect to the RNA quality and concentration. This kit does not use aggressive organic solvents and RNA free of genomic DNA was isolated without the need for DNase treatment.</p
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5â7 vast areas of the tropics remain understudied.8â11 In
the American tropics, Amazonia stands out as the worldâs most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13â15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazonâs biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the regionâs vulnerability to environmental change. 15%â18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio