396 research outputs found
Tripping over emerging pathogens around the world: A phylogeographical approach for determining the epidemiology of Porcine circovirus-2 (PCV-2), considering global trading
AbstractPorcine circovirus-2 (PCV-2) is an emerging virus associated with a number of different syndromes in pigs known as Porcine Circovirus Associated Diseases (PCVAD). Since its identification and characterization in the early 1990s, PCV-2 has achieved a worldwide distribution, becoming endemic in most pig-producing countries, and is currently considered as the main cause of losses on pig farms. In this study, we analyzed the main routes of the spread of PCV-2 between pig-producing countries using phylogenetic and phylogeographical approaches. A search for PCV-2 genome sequences in GenBank was performed, and the 420 PCV-2 sequences obtained were grouped into haplotypes (group of sequences that showed 100% identity), based on the infinite sites model of genome evolution. A phylogenetic hypothesis was inferred by Bayesian Inference for the classification of viral strains and a haplotype network was constructed by Median Joining to predict the geographical distribution of and genealogical relationships between haplotypes. In order to establish an epidemiological and economic context in these analyses, we considered all information about PCV-2 sequences available in GenBank, including papers published on viral isolation, and live pig trading statistics available on the UN Comtrade database (http://comtrade.un.org/). In these analyses, we identified a strong correlation between the means of PCV-2 dispersal predicted by the haplotype network and the statistics on the international trading of live pigs. This correlation provides a new perspective on the epidemiology of PCV-2, highlighting the importance of the movement of animals around the world in the emergence of new pathogens, and showing the need for effective sanitary barriers when trading live animals
Application of catalysts developed from compost derived from municipal solid waste in the removal of caffeine by wet peroxide oxidation
Nowadays, waste management through mechanical biological treatment (MBT) consists
on the use of the separated organic fraction of municipal solid waste (MSW) to feed anaerobic
digestion processes, resulting therein a solid stream, further processed to compost, which can
be used as fertilizer. Currently, the production of compost from MBT is higher than the existing
demand, and the expected developments on up-coming directives ruling “End-of-waste” criteria
are leading to barriers on the use of waste-derived fertilizers (European Commision, 2013). In
this context, the current work proposes an alternative strategy to the valorisation of compost,
through the production of low-cost materials to be applied in the catalytic wet peroxide
oxidation (CWPO) of synthetic wastewater effluents contaminated with caffeine, used as a
model pollutant of emerging concern. Caffeine is the most consumed psychoactive drug
worldwide. It is one of the components of painkillers, medication against migraine, fatigue,
drowsiness and breathing problems. Its consumption is also associated with an overall lower
risk of malignant growth like hepatocellular, endometrial or colorectal cancer (Ganzenko et al.,
2015). However, the effect of caffeine and its environmental degradation products on aquatic
living species is not properly known. Caffeine, is a world wide consumed psychoactive drug,
in a way that becomes a persistent compound and cannot be efficiently removed by municipal
wastewater treatment facilities (Ganzenko et al., 2015). As a consequence, caffeine and its
metabolites are present in the effluents of wastewater treatment plants (Gracia-Lor et al., 2017).This work was financially supported by project “VALORCOMP -
Valorización de compost y otros desechos procedentes de la fracción orgánica de los residuos
municipales”, 0119_VALORCOMP_2_P, and project “AIProcMat@N2020 - Advanced
Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”,
reference NORTE-01-0145-FEDER-000006, supported by NORTE 2020, under the Portugal
2020 Partnership Agreement, through FEDER, and Project Associate Laboratory LSRE-LCM
- UID/EQU/50020/2019 - funded by national funds through FCT/MCTES (PIDDAC).info:eu-repo/semantics/publishedVersio
Spirulina (Arthrospira platensis) protein-rich extract as a natural emulsifier for oil-in-water emulsions: optimization through a sequential experimental design strategy
Spirulina (Arthrospira platensis) proteins have been proven to present emulsifying properties. In this work, a
Spirulina protein-rich extract obtained by ultrasound extraction (SpE) was tested to stabilize oil-in-water (O/W)
emulsions. For this purpose, a sequential experimental design strategy (Fractional Factorial Design (FFD) 24–1
followed by a Central Composite Rotatable Design (CCRD) 22)) was applied. The effect of four variables, SpE
concentration, O/W weight ratio, pH and storage time, on emulsions’ zeta potential and number-mean droplet
diameter was considered for the FFD 24–1, indicating SpE concentration and storage time as the relevant variables
for the CCRD 22. According to zeta potential and number-mean droplet diameter evaluation, for the studied SpE
concentration range (2–5 wt%), quite stable emulsions were obtained along the tested 30-days period. Even so,
for 5%, visual inspection revealed extract segregation after 20-days. The optimal solution comprised 4 wt% of
SpE, for an O/W weight ratio of 30/70 and a pH of 7.0 (number-mean droplet diameter of 55.66 nm and zeta
potential of -43.83 mV). Overall, SpE has proven to be an excellent emulsifier, offering the potential to substitute animal-based proteins and synthetic emulsifiers. In addition, no signs of contamination by microorganisms
were observed, suggesting that the SpE may also act as an antimicrobial agent.CIMO (Centro de Investigação de Montanha, Portugal) (UIDB/00690/2020), LSRE-LCM (Laboratory of Separation and Reaction Engineering
– Laboratory of Catalysis and Materials, Portugal) (UIDB/50020/2020; UIDP/50020/2020), and ALiCE (Associate Laboratory in Chemical Engineering, Portugal) (LA/P/0045/2020), funded by national funds through Fundação para Ciência e a Tecnologia/Ministério
da Ciência, Tecnologia e Ensino Superior (FCT/MCTES) (PIDDAC). National
funding by Fundação para a Ciência e a Tecnologia (FCT)
(Portugal), P.I., through the institutional scientific employment program
contract with A. Santamaria-Echart, L. Barros, and A. Fernandes. FCT for
the PhD research grant of Samara Cristina da Silva (SFRH/BD/148281/2019) and Giovana Colucci (2021. 05215. BD).info:eu-repo/semantics/publishedVersio
Extensive Sheep and Goat Production: The Role of Novel Technologies towards Sustainability and Animal Welfare
New technologies have been recognized as valuable in controlling, monitoring, and managing farm animal activities. It makes it possible to deepen the knowledge of animal behavior and improve animal welfare and health, which has positive implications for the sustainability of animal production. In recent years, successful technological developments have been applied in intensive farming systems; however, due to challenging conditions that extensive pasture-based systems show, technology has been more limited. Nevertheless, awareness of the available technological solutions for extensive conditions can increase the implementation of their adoption among farmers and researchers. In this context, this review addresses the role of different technologies applied to sheep and goat production in extensive systems. Examples related to precision livestock farming, omics, thermal stress, colostrum intake, passive immunity, and newborn survival are presented; biomarkers of metabolic diseases and parasite resistance breeding are discussed
Acclimation to short-term low temperatures in two Eucalyptus globulus clones with contrasting drought resistance
We tested the hypothesis that Eucalyptus
globulus Labill. genotypes that are more resistant to dry
environments might also exhibit higher cold tolerances
than drought-sensitive plants. The effect of low temperatures
was evaluated in acclimated and unacclimated
ramets of a drought-resistant clone (CN5) and a
drought-sensitive clone (ST51) of E. globulus. We
studied the plants’ response via leaf gas exchanges, leaf
water and osmotic potentials, concentrations of soluble
sugars, several antioxidant enzymes and leaf electrolyte
leakage. Progressively lowering air temperatures (from
24/16 to 10/ 2 C, day/night) led to acclimation of both
clones. Acclimated ramets exhibited higher photosynthetic
rates, stomatal conductances and lower membrane
relative injuries when compared to unacclimated ramets.
Moreover, low temperatures led to significant increases
of soluble sugars and antioxidant enzymes activity
(glutathione reductase, ascorbate peroxidase and superoxide
dismutases) of both clones in comparison to plants
grown at control temperature (24/16 C). On the other
hand, none of the clones, either acclimated or not,
exhibited signs of photoinhibition under low temperatures
and moderate light. The main differences in the
responses to low temperatures between the two clones
resulted mainly from differences in carbon metabolism,
including a higher accumulation of soluble sugars in the
drought-resistant clone CN5 as well as a higher capacity
for osmotic regulation, as compared to the droughtsensitive
clone ST51. Although membrane injury data
suggested that both clones had the same inherent
freezing tolerance before and after cold acclimation,
the results also support the hypothesis that the droughtresistant
clone had a greater cold tolerance at intermediate
levels of acclimation than the drought-sensitive
clone. A higher capacity to acclimate in a short period
can allow a clone to maintain an undamaged leaf surface
area along sudden frost events, increasing growt
Quaternion-Loop Quantum Gravity
It is shown that the Riemannian curvature of the 3-dimensional hypersurfaces
in space-time, described by the Wilson loop integral, can be represented by a
quaternion quantum operator induced by the SU(2) gauge potential, thus
providing a justification for quaternion quantum gravity at the Tev energy
scale.Comment: 5 pages, latex, no figures. Improved pdf. To appear in the
Foundations of Physic
- …