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"Carvalho, Helena"
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A systematic review and meta-analysis on the efficacy of vaccination against colibacillosis in broiler production
by
Paudel, Surya
,
de Carvalho Ferreira, Helena C.
,
Tilli, Giuditta
in
Analysis
,
Animals
,
Antibiotics
2024
Colibacillosis, a disease caused by Escherichia coli in broiler chickens has serious implications on food safety, security, and economic sustainability. Antibiotics are required for treating the disease, while vaccination and biosecurity are used for its prevention. This systematic review and meta-analysis, conducted under the COST Action CA18217—European Network for Optimization of Veterinary Antimicrobial Treatment (ENOVAT), aimed to assess the efficacy of E . coli vaccination in broiler production and provide evidence-based recommendations. A comprehensive search of bibliographic databases, including, PubMed, CAB Abstracts, Web of Science and Agricola, yielded 2,722 articles. Following a defined protocol, 39 studies were selected for data extraction. Most of the studies were experimental infection trials, with only three field studies identified, underscoring the need for more field-based research. The selected studies reported various types of vaccines, including killed (n = 5), subunit (n = 8), outer membrane vesicles/protein-based (n = 4), live/live-attenuated (n = 16), and CpG oligodeoxynucleotides (ODN) (n = 6) vaccines. The risk of bias assessment revealed that a significant proportion of studies reporting mortality (92.3%) or feed conversion ratio (94.8%) as outcomes, had “unclear” regarding bias. The meta-analysis, focused on live-attenuated and CpG ODN vaccines, demonstrated a significant trend favoring both vaccination types in reducing mortality. However, the review also highlighted the challenges in reproducing colibacillosis in experimental setups, due to considerable variation in challenge models involving different routes of infection, predisposing factors, and challenge doses. This highlights the need for standardizing the challenge model to facilitate comparisons between studies and ensure consistent evaluation of vaccine candidates. While progress has been made in the development of E . coli vaccines for broilers, further research is needed to address concerns such as limited heterologous protection, practicability for application, evaluation of efficacy in field conditions and adoption of novel approaches.
Journal Article
Light-dependent signal transduction in the marine diatom Phaeodactylum tricornutum
by
Levitan, Orly
,
Falkowski, Paul G.
,
Agarwal, Ananya
in
Algae
,
Antisense RNA
,
Biological Sciences
2023
Unlike most higher plants, unicellular algae can acclimate to changes in irradiance on time scales of hours to a few days. The process involves an enigmatic signaling pathway originating in the plastid that leads to coordinated changes in plastid and nuclear gene expression. To deepen our understanding of this process, we conducted functional studies to examine how the model diatom, Phaeodactylum tricornutum, acclimates to low light and sought to identify the molecules responsible for the phenomenon. We show that two transformants with altered expression of two putative signal transduction molecules, a light-specific soluble kinase and a plastid transmembrane protein, that appears to be regulated by a long noncoding natural antisense transcript, arising from the opposite strand, are physiologically incapable of photoacclimation. Based on these results, we propose a working model of the retrograde feedback in the signaling and regulation of photoacclimation in a marine diatom.
Journal Article
Global identification of a marine diatom long noncoding natural antisense transcripts (NATs) and their response to phosphate fluctuations
2020
Often ignored and regarded as mere transcriptional noise, long noncoding RNAs (lncRNAs) are starting to be considered key regulators of gene expression across the Eukarya domain of life. In the model diatom
Phaeodactylum tricornutum
, we have previously reported the occurrence of 1,510 intergenic lncRNAs (lincRNAs), many of which displaying specific patterns of expression under phosphate fluctuation (Pi). Using strand-specific RNA-sequencing data we now expand the repertoire of
P. tricornutum
lncRNAs by identifying 2,628 novel natural antisense transcripts (NATs) that cover 21.5% of the annotated genomic loci. We found that NAT expression is tightly regulated by phosphate depletion and other naturally occurring environmental stresses. Furthermore, we identified 121 phosphate stress responsive NAT-mRNA pairs, the great majority of which showing a positive correlation (concordant pairs) and a small fraction with negative correlation (discordant pairs). Taken together our results show that NATs are highly abundant transcripts in
P. tricornutum
and that their expression is under tight regulation by nutrient and environmental stresses. Furthermore, our results suggest that in
P. tricornutum
Pi stress response NAT pairs predominantly regulate positively the expression of their cognate sense genes, the latter being involved in several biological processes underlying the control of cellular homeostasis under stress.
Journal Article
From Chaos to Normalization and Deconfinement: What did the Pandemic Unveil in Youth Residential Care
by
Costa, Mónica
,
Carvalho, Helena M
,
Santos, Beatriz
in
Adoption (Ideas)
,
Best practice
,
COVID-19
2023
The conditions imposed by the Covid-19 outbreaks forced residential care (RC) facilities to experience new challenges and to adopt new practices. The aim of the current study is to analyze how RC facilities have experienced and managed confinement during the 1st wave of the pandemic. A thematic analysis of 20 semi-structured interviews were conducted with professionals responsible for managing crisis in RC facilities. The main implications of the confinement measures on RC dynamics and relations were organized in three major themes: Chaos, novelty and organization; reinventing normalization and deconfinement. The pandemic exposes the structural weaknesses of RC, namely mobility of human resources, scarcity of supportive networks, and fragilities in providing comprehensive and integrative care. These factors need to be considered when addressing risk/vulnerability and discussing best practices and policies on child/youth welfare domain. Future studies should explore representations of important key actors as youth, families and other professionals from youth care.
Journal Article
Asymptomatic Plasmodium vivax malaria in the Brazilian Amazon: Submicroscopic parasitemic blood infects Nyssorhynchus darlingi
by
Gomes, Gabriela Ribeiro
,
Castro, Marcia Caldas de
,
Figueiredo, Maria Marta
in
Animals
,
Anopheles
,
Anopheles - parasitology
2021
Individuals with asymptomatic infection due to Plasmodium vivax are posited to be important reservoirs of malaria transmission in endemic regions. Here we studied a cohort of P . vivax malaria patients in a suburban area in the Brazilian Amazon. Overall 1,120 individuals were screened for P . vivax infection and 108 (9.6%) had parasitemia detected by qPCR but not by microscopy. Asymptomatic individuals had higher levels of antibodies against P . vivax and similar hematological and biochemical parameters compared to uninfected controls. Blood from asymptomatic individuals with very low parasitemia transmitted P . vivax to the main local vector, Nyssorhynchus darlingi . Lower mosquito infectivity rates were observed when blood from asymptomatic individuals was used in the membrane feeding assay. While blood from symptomatic patients infected 43.4% (199/458) of the mosquitoes, blood from asymptomatic infected 2.5% (43/1,719). However, several asymptomatic individuals maintained parasitemia for several weeks indicating their potential role as an infectious reservoir. These results suggest that asymptomatic individuals are an important source of malaria parasites and Science and Technology for Vaccines granted by Conselho Nacional de may contribute to the transmission of P . vivax in low-endemicity areas of malaria.
Journal Article
Animal sources of antimicrobial-resistant bacterial infections in humans: a systematic review
by
di Bari, Carlotta
,
Pires, Sara Monteiro
,
Pigott, David
in
Animal-based foods
,
Animals
,
Anti-Bacterial Agents - pharmacology
2023
Bacterial antimicrobial resistance (AMR) is among the leading global health challenges of the century. Animals and their products are known contributors to the human AMR burden, but the extent of this contribution is not clear. This systematic literature review aimed to identify studies investigating the direct impact of animal sources, defined as livestock, aquaculture, pets, and animal-based food, on human AMR. We searched four scientific databases and identified 31 relevant publications, including 12 risk assessments, 16 source attribution studies, and three other studies. Most studies were published between 2012 and 2022, and most came from Europe and North America, but we also identified five articles from South and South-East Asia. The studies differed in their methodologies, conceptual approaches (bottom-up, top-down, and complex), definitions of the AMR hazard and outcome, the number and type of sources they addressed, and the outcome measures they reported. The most frequently addressed animal source was chicken, followed by cattle and pigs. Most studies investigated bacteria–resistance combinations. Overall, studies on the direct contribution of animal sources of AMR are rare but increasing. More recent publications tailor their methodologies increasingly towards the AMR hazard as a whole, providing grounds for future research to build on.
Journal Article
Glutamine Synthetase Is a Molecular Target of Nitric Oxide in Root Nodules of Medicago truncatula and Is Regulated by Tyrosine Nitration
by
Melo, Paula M.
,
Silva, Liliana S.
,
Carvalho, Helena G.
in
Agronomy. Soil science and plant productions
,
Amino Acid Sequence
,
Biological and medical sciences
2011
Nitric oxide (NO) is emerging as an important regulatory player in the Rhizobium-legume symbiosis, but its biological role in nodule functioning is still far from being understood. To unravel the signal transduction cascade and ultimately NO function, it is necessary to identify its molecular targets. This study provides evidence that glutamine synthetase (GS), a key enzyme for root nodule metabolism, is a molecular target of NO in root nodules of Medicago truncatula, being regulated by tyrosine (Tyr) nitration in relation to active nitrogen fixation. In vitro studies, using purified recombinant enzymes produced in Escherichia coli, demonstrated that the M. truncatula nodule GS isoenzyme (MtGSla) is subjected to NO-mediated inactivation through Tyr nitration and identified Tyr-167 as the regulatory nitration site crucial for enzyme inactivation. Using a sandwich enzymelinked immunosorbent assay, it is shown that GS is nitrated in planta and that its nitration status changes in relation to active nitrogen fixation. In ineffective nodules and in nodules fed with nitrate, two conditions in which nitrogen fixation is impaired and GS activity is reduced, a significant increase in nodule GS nitration levels was observed. Furthermore, treatment of root nodules with the NO donor sodium nitroprusside resulted in increased in vivo GS nitration accompanied by a reduction in GS activity. Our results support a role of NO in the regulation of nitrogen metabolism in root nodules and places GS as an important player in the process. We propose that the NO-mediated GS posttranslational inactivation is related to metabolite channeling to boost the nodule antioxidant defenses in response to NO.
Journal Article
Differential expression patterns of long noncoding RNAs in a pleiomorphic diatom and relation to hyposalinity
by
Cruz de Carvalho, Helena
,
Bowler, Chris
,
Charton, Florent
in
631/449
,
631/449/1659
,
631/449/448
2023
Long non-coding (lnc)RNAs have been shown to have central roles in stress responses, cell identity and developmental processes in multicellular organisms as well as in unicellular fungi. Previous works have shown the occurrence of lncRNAs in diatoms, namely in
Phaeodactylum tricornutum
, many of which being expressed under specific stress conditions. Interestingly,
P. tricornutum
is the only known diatom that has a demonstrated morphological plasticity, occurring in three distinct morphotypes: fusiform, triradiate and oval. Although the morphotypes are interchangeable, the fusiform is the dominant one while both the triradiate and the oval forms are less common, the latter often being associated with stress conditions such as low salinity and solid culture media, amongst others. Nonetheless, the molecular basis underpinning morphotype identity in
P. tricornutum
remains elusive. Using twelve previously published transcriptomic datasets originating from the three morphotypes of
P. tricornutum
, we sought to investigate the expression patterns of lncRNAs (lincRNAs and NATs) in these distinct morphotypes, using pairwise comparisons, in order to explore the putative involvement of these noncoding molecules in morphotype identity. We found that differentially expressed lncRNAs cluster according to morphotype, indicating that lncRNAs are not randomly expressed, but rather seem to provide a specific (noncoding) transcriptomic signature of the morphotype. We also present evidence to suggest that the major differences in DE genes (both noncoding and coding) between the stress related oval morphotype and the most common fusiform morphotype could be due, to a large extent, to the hyposaline culture conditions rather than to the morphotype itself. However, several lncRNAs associated to each one of the three morphotypes were identified, which could have a potential role in morphotype (or cell) identity in
P. tricornutum
, similar to what has been found in both animals and plant development.
Journal Article
A Combined Use of TRIZ Methodology and Eco-Compass tool as a Sustainable Innovation Model
by
Helena Navas
,
Hiroshi Hasegawa
,
Rodrigo Boavida
in
Biology (General)
,
Case studies
,
Cellular telephone equipment industry
2020
In recent years, there has been an increase in the adoption of quality tools by companies. As such, there has been a commitment to innovation by the organizations to obtain competitive advantages by the development of new products and technologies focused on the creation of economic value but also on delivering sustainability. This study aims to develop an application model of the inventive resolution theory in conjunction with the Eco-Compass ecological innovation tool, in order to allow solutions to be obtained systematically, and to present a performance increase of certain environmental parameters, promoting thus sustainable innovation. The case study research methodology is used to frame the research. The company under study is Nokia enterprise, located in Portugal, which offers a set of services related to telecommunications infrastructures. The unit of analysis is the department of transformation and continuous improvement, and the study illustrated the application of combined use of theory of inventive problem solving (TRIZ) and Eco-compass to develop innovative solutions systematically. The results show that it is possible to achieve innovation according to a certain level of established sustainable environmental parameters, while at the same time solving the identified inventive problem.
Journal Article
Supply Chain Sustainability: A Model to Assess the Maturity Level
by
Correia, Elisabete
,
Carvalho, Helena
,
Garrido-Azevedo, Susana
in
Best practice
,
Corporate sustainability
,
intra- and inter-organizational perspective
2023
Today, frameworks and models are critical for enabling organizations to identify their current sustainability integration into business and to follow up on these initiatives over time. In this context, the maturity models offer a structured way of analyzing how a supply chain meets specific sustainability requirements and which areas demand attention to reach maturity levels. This study proposes a five-level maturity model to help supply chains managers identify their level of engagement with sustainability practices combining three perspectives: the intra- and inter-organizational sustainability practices, the triple-bottom-line approach and the critical areas for sustainability. All the steps followed in constructing the maturity model were based on a literature review, and case studies supported its improvement, application, and testing. The proposed model presents many advantages, such as being used as a self-assessment tool, a roadmap for sustainability behaviors improvement, and a benchmarking tool to evaluate and compare standards and best practices among organizations and supply chains.
Journal Article