26 research outputs found
A Galvanic Sensor for Monitoring the Corrosion Condition of the Concrete Reinforcing Steel: Relationship Between the Galvanic and the Corrosion Currents
This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, Igal, and the corrosion currents, Icorr, estimated from the polarization resistance, Rp. Sensors have been tested in saturated Ca(OH)2 aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O2. For all the conditions, the influence of temperature (20 to 55 °C) has also been considered. From this study, it could be concluded that the galvanic currents are sensitive to the various parameters following a trend similar to that of the Rp values. A relationship between the galvanic and the corrosion current densities was obtained and the limiting values of the Igal, indicative of the state condition of the reinforcing steel for the designed sensor, were established
Decrease of CD68 Synovial Macrophages in Celastrol Treated Arthritic Rats
Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease characterized by cellular infiltration into the joints, hyperproliferation of synovial cells and bone damage. Available treatments for RA only induce remission in around 30% of the patients, have important adverse effects and its use is limited by their high cost. Therefore, compounds that can control arthritis, with an acceptable safety profile and low production costs are still an unmet need. We have shown, in vitro, that celastrol inhibits both IL-1β and TNF, which play an important role in RA, and, in vivo, that celastrol has significant anti-inflammatory properties. Our main goal in this work was to test the effect of celastrol in the number of sublining CD68 macrophages (a biomarker of therapeutic response for novel RA treatments) and on the overall synovial tissue cellularity and joint structure in the adjuvant-induced rat model of arthritis (AIA).FCT fellowship: (SFRH/BPD/92860/2013)
In vitro co-cultures of Pinus pinaster with Bursaphelenchus xylophilus: a biotechnological approach to study pine wilt disease
Abstract
Main conclusion Co-cultures of Pinus pinaster with
Bursaphelenchus xylophilus were established as a
biotechnological tool to evaluate the effect of nematotoxics
addition in a host/parasite culture system.
The pinewood nematode (PWN), Bursaphelenchus xylophilus,
the causal agent of pine wilt disease (PWD), was
detected for the first time in Europe in 1999 spreading
throughout the pine forests in Portugal and recently in
Spain. Plant in vitro cultures may be a useful experimental
system to investigate the plant/nematode relationships in
loco, thus avoiding the difficulties of field assays. In this
study, Pinus pinaster in vitro cultures were established and
compared to in vivo 1 year-old plantlets by analyzing shoot
structure and volatiles production. In vitro co-cultures were
established with the PWN and the effect of the phytoparasite
on in vitro shoot structure, water content and
volatiles production was evaluated. In vitro shoots showed
similar structure and volatiles production to in vivo maritime
pine plantlets. The first macroscopic symptoms of
PWD were observed about 4 weeks after in vitro co-culture
establishment. Nematode population in the culture medium
increased and PWNs were detected in gaps of the callus
tissue and in cavities developed from the degradation of
cambial cells. In terms of volatiles main components,
plantlets, P. pinaster cultures, and P. pinaster with B. xylophilus
co-cultures were all b- and a-pinene rich. Cocultures
may be an easy-to-handle biotechnological approach
to study this pathology, envisioning the understanding
of and finding ways to restrain this highly
devastating nematode.
Keywords Maritime pine ! Monoxenic culture !
Pinewood nematode ! Relative water content ! Shoots
structure ! Volatiles
Abbreviations
BAP 6-Benzylaminopurine
DAI Days after inoculation
EPPO European and Mediterranean Plant Protectio
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,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s 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.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s 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 region’s vulnerability to environmental change. 15%–18% 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
In vitro co-cultures of Pinus pinaster with Bursaphelenchus xylophilus: a biotechnological approach to study pine wilt disease
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 understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected 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 lost
Seasonal availability of floral resources and ambient temperature shape stingless bee foraging behavior (Scaptotrigona aff. depilis)
Validação relativa de Questionário de Freqüência Alimentar em gestantes usuárias de serviços do Sistema Único de Saúde em dois municípios no Rio Grande do Sul, Brasil
Digestibilidade aparente dos nutrientes e energia de ração suplementada com enzimas digestivas exógenas para juvenis de tambaqui (Colosssoma macropomum Cuvier, 1818) Apparent digestibility of nutrients and crude energy in diets with addition of exogenous digestive enzymes in tambaqui juveniles ( Colosssoma macropomum Cuvier, 1818)
O experimento foi conduzido com o objetivo de avaliar o efeito da adição de um compelxo multienzimático exógeno composto de amilase, protease, lipase e celulase, em rações de juvenis de tambaqui, sobre os coeficientes de digestibilidade aparente (CDa) da proteína bruta (PB), extrato etéreo (EE), carboidratos (ENN) e energia bruta (EB). O delineamento experimental foi inteiramente casualizado com quatro tratamentos (quatro níveis de inclusão de enzimas, 0,0; 0,05; 0,10; e 0,15 %), três repetições (no tempo) e 10 peixes por unidade experimental. Foram utilizados 40 juvenis de tambaqui, com peso médio de 155,0 ± 0,49 g, distribuídos em quatro tanques de alimentação de 500 l, recebendo refeições à vontade das 8 às 12h, a cada hora. Em seguida os animais foram transferidos para coletores de fezes (200 l), onde permaneceram até às 18h, sendo a coleta de dejetos realizada a cada hora. A determinação dos CDa foi realizada pelo método indireto, sendo utilizado como indicador externo 0,5% de óxido de cromo-III (Cr2O3) incorporado à ração. Os resultados demonstraram que a suplementação das dietas com enzimas exógenas para juvenis de tambaqui aumenta a digestibilidade aparente dos nutrientes e energia bruta, no nível de inclusão de 0,05% (P<0,05%).<br>The experiment evaluated the effect of dietary supplementation a multienzyme complex containing amylase, protease, lipase and cellulase for tambaqui juveniles on the apparent digestibility coefficients (ADCs) of crude protein (CP), ether extract (EE), carbohydrates (CHO) and crude energy (CE). A completely randomized experimental design was used with four treatments (level of enzymes 0.0; 0.05; 0.10; and 0.15 %) and three replicates (over time), with ten fish per experimental unity. Forty fish weighting 155.0 ± 0.49g were distributed in four 500 l feeding tanks and were fed hourly, from 8 to 12 AM. After this period, fish were transferred for fecal collection units until 6 PM, where feces were collected hourly. ADCs were evaluated by an indirect method, with 0.5 % III-chromic oxide (Cr2O3) as innert marker. The results showed that supplementary exogenous enzymes on tambaqui diets increased the apparent digestibility of nutrients and crude energy at inclusion level of 0.05% (P<0.05%)