991 research outputs found
Carcass conformation and joints composition of Churra Galega Bragançana and crossbred lambs by Suffolk and Merino Precoce sire breeds
Carcasses of Churro Galego Bragançano purebred and Suffolk and Merino Precoce crossbred lambs reared under
three different conventional production system of northeast of Portugal were evaluated. Carcasses of male lambs had
larger muscle longissimus width (P < 0.05) and smaller subcutaneous fat thickness (P < 0.05) than the female lambs.
Carcasses of crossbred lambs had higher (P < 0.05) compactness indices and leg and shoulder proportion than Bragançano
purebred. Suffolk crossed had lower KKCF proportion (P < 0.05) than Bragançano and Merino crossbred
lambs. Male lambs had higher (P < 0.05) muscle proportion in almost all carcass joints than the female lambs. It was
concluded that Suffolk can be used as sire breed in Bragançano ewes to produce lambs with leaner and more compact
carcasses and better fat distribution, which allows slaughtering at higher slaughter weight, specially in more intensive
production systems. Female lambs should be slaughtered at lower carcass weight than male lambs in order to produce
carcasses with the same fattening degree
Carcass conformation and joints composition of Churra Galega Bragançana and crossbred lambs by Suffolk and Merino Precoce sire breeds
Carcasses of Churro Galego Bragançano purebred and Suffolk and Merino Precoce crossbred lambs reared under
three different conventional production system of northeast of Portugal were evaluated. Carcasses of male lambs had
larger muscle longissimus width (P < 0.05) and smaller subcutaneous fat thickness (P < 0.05) than the female lambs.
Carcasses of crossbred lambs had higher (P < 0.05) compactness indices and leg and shoulder proportion than Bragançano
purebred. Suffolk crossed had lower KKCF proportion (P < 0.05) than Bragançano and Merino crossbred
lambs. Male lambs had higher (P < 0.05) muscle proportion in almost all carcass joints than the female lambs. It was
concluded that Suffolk can be used as sire breed in Bragançano ewes to produce lambs with leaner and more compact
carcasses and better fat distribution, which allows slaughtering at higher slaughter weight, specially in more intensive
production systems. Female lambs should be slaughtered at lower carcass weight than male lambs in order to produce
carcasses with the same fattening degree
Efecto del peso y del sexo sobre la calidad de la canal y de la carne de corderos de la raza Churra Galega Mirandesa
La creación de Denominaciones de Origen Protegidas para los productos de
la ovinocultura de Portugal conlleva la necesidad de la caracterización y
estandarización de las canales y de la carne de corderos de razas autóctonas, poco
conocidas científicamente. Las características de las canales como: composición
tisular, regional y anatómica esta altamente relacionada con su peso, sexo y otros
(Delfa y Teixeira, 1998). Así, el objetivo de este estudio fue evaluar las
características de la canal y de la carne de corderos machos y hembras de la raza
Churra Galega Mirandesa sacrificados a dos pesos distintos
Nonlinear force-free magnetic field extrapolations: comparison of the Grad-Rubin and Wheatland-Sturrock-Roumeliotis algorithm
We compare the performance of two alternative algorithms which aim to
construct a force-free magnetic field given suitable boundary conditions. For
this comparison, we have implemented both algorithms on the same finite element
grid which uses Whitney forms to describe the fields within the grid cells. The
additional use of conjugate gradient and multigrid iterations result in quite
effective codes. The Grad-Rubin and Wheatland-Sturrock-Roumeliotis algorithms
both perform well for the reconstruction of a known analytic force-free field.
For more arbitrary boundary conditions the Wheatland-Sturrock-Roumeliotis
approach has some difficulties because it requires overdetermined boundary
information which may include inconsistencies. The Grad-Rubin code on the other
hand loses convergence for strong current densities. For the example we have
investigated, however, the maximum possible current density seems to be not far
from the limit beyond which a force free field cannot exist anymore for a given
normal magnetic field intensity on the boundary.Comment: 21 pages, 13 figure
Effect of lunging exercise program with Pessoa training aid on cardiac physical conditioning predictors in adult horses
ABSTRACT The aim of this study was to evaluate the effect the Pessoa training aid (PTA) exercise program exerts in some physical conditioning predictors. Eight detrained adult horses were evaluated in 12 sessions of work with PTA (3 sessions per week). All horses used a heart rate monitor and GPS (V800, Polar Electro) and data was used to calculate energy expenditure (EE), net cost of transport (COT), metabolic energy requirement (Pmet), oxygen pulse, oxygen utilization, heart rate and heart rate variability (HRV). The horses were weighted, and the thoracolumbar shape were measured at the level of the 18th (T18), 13th (T13) and 8th (T8) thoracic vertebrae with a flexible ruler before and after the experimental period. Data obtained weekly were submitted to ANOVA and Tukey test (p≤0.05). Data obtained just before and after the experimental period were submitted to paired t test. There was a decrease in left-right asymmetry. In the third week there was an increase in HR, EE, oxygen pulse and oxygen utilization followed by a decrease in the fourth week. The biomechanics related parameters, COT and Pmet decreased week by week. The HRV showed a sympathetic stimulus in the third week followed by a shift to parasympathetic in the fourth week. We conclude that 12 sessions of lunge exercise with PTA contributed to physical condition improvement
Have the cake and eat it: optimizing nondestructive DNA metabarcoding of macroinvertebrate samples for freshwater biomonitoring
Resource ArticleDNA metabarcoding can contribute to improving cost‐effectiveness and accuracy of
biological assessments of aquatic ecosystems, but significant optimization and standardization
efforts are still required to mainstream its application into biomonitoring
programmes. In assessments based on freshwater macroinvertebrates, a key challenge
is that DNA is often extracted from cleaned, sorted and homogenized bulk
samples, which is time‐consuming and may be incompatible with sample preservation
requirements of regulatory agencies. Here, we optimize and evaluate metabarcoding
procedures based on DNA recovered from 96% ethanol used to preserve field
samples and thus including potential PCR inhibitors and nontarget organisms. We
sampled macroinvertebrates at five sites and subsampled the preservative ethanol at
1 to 14 days thereafter. DNA was extracted using column‐based enzymatic (TISSUE)
or mechanic (SOIL) protocols, or with a new magnetic‐based enzymatic protocol
(BEAD), and a 313‐bp COI fragment was amplified. Metabarcoding detected at least
200 macroinvertebrate taxa, including most taxa detected through morphology and
for which there was a reference barcode. Better results were obtained with BEAD
than SOIL or TISSUE, and with subsamples taken 7–14 than 1–7 days after sampling,
in terms of DNA concentration and integrity, taxa diversity and matching between
metabarcoding and morphology. Most variation in community composition was explained
by differences among sites, with small but significant contributions of subsampling
day and extraction method, and negligible contributions of extraction and
PCR replication. Our methods enhance reliability of preservative ethanol as a potential
source of DNA for macroinvertebrate metabarcoding, with a strong potential application
in freshwater biomonitoringinfo:eu-repo/semantics/publishedVersio
Tuning the bioactivity of tensioactive deoxy glycosides to structure: antibacterial activity versus selective cholinesterase inhibition rationalized by molecular docking
New octyl/dodecyl 2,6-dideoxy-D-arabino-hexopyranosides
have been synthesized by a simple but efficient methodology
based on the reaction of glycals with alcohols catalysed by
triphenylphosphane hydrobromide, deprotection, regioselective tosylation and reduction. Their surface-active properties
were evaluated in terms of adsorption and aggregation parameters and compared with those of 2-deoxy-D-glycosides
and 2,6-dideoxy-L-glycosides. Deoxygenation at the 6-position led to a decrease in the critical micelle concentration,
and an increase in the adsorption efficiency (pC20) promoting
aggregation more efficiently than adsorption. With regard to
the antibacterial activity, dodecyl 2,6-dideoxy-α-L-arabino-hexopyranoside was the most active compound towards Bacillus anthracis (MIC 25 μM), whereas its enantiomer exhibited a MIC value of 50 μM. Both 2,6-dideoxy glycosides were
active towards Bacillus cereus, Bacillus subtilis, Enterococcus
faecalis and Listeria monocytogenes. In contrast, none of the
2-deoxy glycosides was significantly active. These results
and the data on surface activity suggest that aggregation is
a key issue for antimicrobial activity. Beyond infection, Alzheimer’s disease also threatens elderly populations. In the search for butyrylcholinesterase (BChE) selective inhibition, 2-
deoxy glycosides were screened in vitro by using Ellman’s
assay. Octyl 2-deoxy-α-D-glycoside was found to be a BChE
selective inhibitor promoting competitive inhibition. Docking
studies supported these results as they pinpoint the importance of the primary OH group in stabilizing the BChE inhibitor complex. A size-exclusion mechanism for inhibition has
been proposed based on the fact that acetylcholinesterase
(AChE) exhibits several bulky residues that hinder access to
the active-site cavity. This work shows how the deoxygenation pattern, configuration and functionality of the anomeric
centre can tune physical and surface properties as well as
the bioactivity of these multifunctional and stereochemically
rich molecules.FEDER e FCTinfo:eu-repo/semantics/publishedVersio
Arbuscular Mycorrhiza Extraradical Mycelium Promotes Si and Mn Subcellular Redistribution in Wheat Grown under Mn Toxicity
Abstract: Manganese (Mn) and aluminum (Al) toxicities are serious edaphic limitations to crop
production in acidic soils. Excess Mn can be countered using a stress-adapted soil microbiota that
establish symbiotic relationships with native plants. The arbuscular mycorrhizal fungi (AMF) associated with Lolium rigidum L. develop extraradical mycelia (ERM) that quickly colonize wheat and
lead to greater shoot growth by promoting stress-evading mechanisms that are not yet completely explained. In the present study, wheat growth was assessed after 3 weeks on disturbed and undisturbed
(intact ERM) acidic soil where the native non-mycotrophic Silene gallica L. or strongly mycotrophic
L. rigidum were previously developed. The physiological and biochemical mechanisms responsible for increased growth were analyzed by assessing wheat leaf chlorophyll content, photosystem
II quantum yield and performance index, enzymatic activity of ascorbate peroxidase (APX), catalase
(CAT), glutathione reductase (GR), guaiacol peroxidase (GPX), superoxide dismutase (SOD) and
contents and subcellular localization of Mn, Mg, Si and K. The soil from native plants had a beneficial
effect on shoot weight and chlorophyll levels. The highest benefits were obtained for wheat grown in
soil with intact ERM associated with L. rigidum. In this condition, where earlier mycorrhization was
favored, the Mn content decreased, alongside the content of Si, while the Mg/Mn ratio increased. Mn
was redirected to the apoplast, while Si was redirected to the symplast. The activity of APX, GPX and
SOD increased, probably due to increased metabolic growth (higher shoot weight and chlorophyll
content). Understanding the mechanisms induced by native AMF responsible for increasing wheat
performance can contribute to the establishment of sustainable approaches for crop production in
acidic soils with Mn toxicity. The use of native plant AMF developers can improve the sustainable
use of natural resources in the scope of greener agricultural practice
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