92 research outputs found
Biotic and abiotic interactions in temporary summer pools of southern Portugal
In the south of Portugal, the summer season is characterized by reduced precipitation and high air temperatures, which causes the disruption of surface flow and subsequent formation of disconnect pools that may dry out entirely. During this dry period, there is a natural decrease of water quality standards due to the lack of water, leaving temporary rivers very vulnerable. Nevertheless, the remaining pools and surroundings become important in the survival of biological communities.
Aquatic macroinvertebrates were sampled in several pools during the summer period (in the beginning and before the ending), in temporary tributaries of the Degebe River (Guadiana catchment), to quantify the response of macroinvertebrates communities to seasonal desiccation and habitat fragmentation. It we collected thousands individuals, representing 27 families of macroinvertebrates. Changes in the composition and abundance were affected by temporal variability in pool volume and location in the watershed. Smaller, upstream pools showed less diversity and abundance than downstream pools. Higher biological interactions and higher level of relationships with terrestrial ecosystems were perceptible for smaller summer pools. Pools were typically dominated by tolerant taxa such as midge larvae (Chironomidae), lesser boatman (Corixidae) and Oligochaeta, resulting in low diversity of communities over time.
The results indicated the importance and impact of changes in habitat quality, size and connectivity in aquatic macroinvertebrates communities. They also revealed the importance of preservation and conservation of temporary ecosystems, particularly during the dry season, when the anthropogenic interference in ecosystems is more evident and can jeopardize the biodiversity maintenance of these systems
p53 Activation Effect in the Balance of T Regulatory and Effector Cell Subsets in Patients With Thyroid Cancer and Autoimmunity
Carcinomas evade the host immune system by negatively modulating CD4+ and CD8+ T effector lymphocytes through forkhead box protein 3 (FOXP3) positive T regulatory cells' increased activity. Furthermore, interaction of the programmed cell death 1 (PD1) molecule and its ligand programmed cell death ligand 1 (PDL1) inhibits the antitumor activity of PD1+ T lymphocytes. Immunotherapy has become a powerful strategy for tailored cancer patients' treatment both in adult and pediatric patients aiming to generate potent antitumor responses. Nevertheless, immunotherapies can generate autoimmune responses. This study aimed to investigate the potential effect of the transformation-related protein 53 (p53) reactivation by a peptide-based inhibitor of the MDM2/MDM4 heterodimer (Pep3) on the immune response in a solid cancer, i.e., thyroid carcinoma frequently presenting with thyroid autoimmunity. In peripheral blood mononuclear cell of thyroid cancer patients, Pep3 treatment alters percentages of CD8+ and CD4+ T regulatory and CD8+ and CD4+ T effector cells and favors an anticancer immune response. Of note that reduced frequencies of activated CD8+ and CD4+ T effector cells do not support autoimmunity progression. In evaluating PD1 expression under p53 activation, a significant decrease of activated CD4+PD1+ cells was detected in thyroid cancer patients, suggesting a defective regulation in the initial activation stage, therefore generating a protective condition toward autoimmune progression
Combining Averting Behavior and Contingent Valuation Data: an Application to Drinking Water Treatment
This paper is an empirical application that combines averting behavior with contingent valuation data. Consistency tests are performed incorporating alternative heteroscedastic structures in the bivariate probit models by taking advantage of the different information content that characterizes each data source. We look at three covariates not yet examined in the literature when combining stated and revealed preferred data to explain the variance in the models: income, the bid in the contingent valuation questionnaire, and the distance between the bid and the averting expenditures with drinking water. The models estimated include between and within data sources heteroscedasticity. The results obtained allow the combination of the two data sources under a common preference structure.N/
TCD4pos lymphocytosis in rheumatoid and psoriatic arthritis patients following TNFα blocking agents
BACKGROUND:
Lymphocyte expansion and true lymphocytosis are commonly observed in the everyday clinical practice. The meaning of such phenomenon is often poorly understood so that discrimination between benign and malignant lymphocytosis remains difficult to establish. This is mainly true when lymphocytosis rises in patients affected by immune-mediated chronic inflammatory diseases under immunosuppressive treatment, conditions potentially associated with lymphomagenesis. In this brief report the development of mild T CD4pos lymphocytosis in a group of patients with chronic arthritis under anti-TNF-α treatment is described.
METHODS:
Two hundred eight rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients have been evaluated longitudinally for at least 1-year before and 2-years after anti-TNF-α therapy introduction for the possible appearance of a lymphocyte expansion. In patients who developed lymphocyte expansion, T, B and NK cells were analysed.
RESULTS:
Twenty-five out of 208 (12%) subjects developed a mild T CD4pos lymphocytosis, during anti-TNF-α therapy, which reverted after its interruption. Higher lymphocyte count, more frequent use of steroids and shorter disease duration, before biological therapy start, have emerged as risk factors for lymphocytosis development.
CONCLUSIONS:
This is the first longitudinal cohort study evaluating the onset of lymphocytosis in RA and PsA patients under anti-TNF-α treatment and its possible clinical relevance. A mild T CD4pos lymphocytosis has been observed in 12% of RA and PsA patients probably related to anti-TNF-α treatment as previously reported by anecdotal cases. Patients with higher baseline lymphocyte count, use of steroids and shorter disease duration before the introduction of biologic therapy, seem to be prone to develop this laboratory reversible abnormality
Identifying Nonrational Behavior in Recreation Demand Models
In the context of an estimated RPL (Random Parameters Logit) choice model of recreational demand for the game reserves of the KwaZulu-Natal province in South Africa, a test on the existence of an underlying rational preference structure is presented. The proposed procedure allows to identify nonrational behavior in the sample. Using two different data sets extracted from the original data base, we show that by improving the data, apparent nonrationality can be eliminated and welfare analysis may be safely conducted.N/
Positive Selection of B Cells Expressing Low Densities of Self-reactive BCRs
B cell tolerance or autoimmunity is determined by selective events. Negative selection of self-reactive B cells is well documented and proven. In contrast, positive selection of conventional B cells is yet to be firmly established. Here, we demonstrate that developing self-reactive B cells are not always highly sensitive to the deletion mechanisms imposed by membrane-bound self-antigens. At low amounts, membrane-bound antigens allow survival of B cells bearing a single high affinity self-reactive B cell receptor (BCR). More importantly, we show that forced allelic inclusion modifies B cell fate; low quantities of self-antigen induce the selection and accumulation of increased numbers of self-reactive B cells with decreased expression of antigen-specific BCRs. By directly measuring antigen binding by intact B cells, we show that the low amounts of self-antigen select self-reactive B cells with a lower association constant. A fraction of these B cells is activated and secretes autoantibodies that form circulating immune complexes with self-antigen. These findings demonstrate that conventional B cells can undergo positive selection and that the fate of a self-reactive B cell depends on the quantity of self-antigen, the number of BCRs engaged, and on its overall antigen-binding avidity, rather than on the affinity of individual BCRs
Alqueva hydro-meteorological experiment(alex): first results of aquatic ecological assessment
The ALqueva hydro-meteorological EXperiment (ALEX) field campaign took place monthly during summer 2014 and consisted in in situ measurements and sampling of water and biological elements, collected from three fixed platforms placed in the lacustrine zone.
This integrated overview, including meteorological, environmental and biological results contributes to improve the knowledge of the reservoir dynamics and therefore to propose adequate management measures to preserve the observed biological integrity
Snapshot of resistome, virulome and mobilome in aquaculture
Aquaculture environments can be hotspots for resistance genes through the surrounding environment. Our objective was to study the resistome, virulome and mobilome of Gram-negative bacteria isolated in seabream and bivalve molluscs, using a WGS approach. Sixty-six Gram-negative strains (Aeromonadaceae, Enterobacteriaceae, Hafniaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Vibrionaceae, and Yersiniaceae families) were selected for genomic characterization. The species and MLST were determined, and antibiotic/disinfectants/heavy metals resistance genes, virulence determinants, MGE, and pathogenicity to humans were investigated. Our study revealed new sequence-types (e.g. Aeromonas spp. ST879, ST880, ST881, ST882, ST883, ST887, ST888; Shewanella spp. ST40, ST57, ST58, ST60, ST61, ST62; Vibrio spp. ST206, ST205). >140 different genes were identified in the resistome of seabream and bivalve molluscs, encompassing genes associated with β-lactams, tetracyclines, aminoglycosides, quinolones, sulfonamides, trimethoprim, phenicols, macrolides and fosfomycin resistance. Disinfectant resistance genes qacE-type, sitABCD-type and formA-type were found. Heavy metals resistance genes mdt, acr and sil stood out as the most frequent. Most resistance genes were associated with antibiotics/disinfectants/heavy metals commonly used in aquaculture settings. We also identified 25 different genes related with increased virulence, namely associated with adherence, colonization, toxins production, red blood cell lysis, iron metabolism, escape from the immune system of the host. Furthermore, 74.2 % of the strains analysed were considered pathogenic to humans. We investigated the genetic environment of several antibiotic resistance genes, including blaTEM-1B, blaFOX-18, aph(3″)-Ib, dfrA-type, aadA1, catA1-type, tet(A)/(E), qnrB19 and sul1/2. Our analysis also focused on identifying MGE in proximity to these genes (e.g. IntI1, plasmids and TnAs), which could potentially facilitate the spread of resistance among bacteria across different environments. This study provides a comprehensive examination of the diversity of resistance genes that can be transferred to both humans and the environment, with the recognition that aquaculture and the broader environment play crucial roles as intermediaries within this complex transmission network.Highlights: - New STs (17) and possible evolutionary relationships with other STs were identified. - Over 140 resistance genes provided a snapshot of the aquaculture resistome. - Many resistance genes found are common to those of clinical isolates (e.g. qnrB19). - Many ARGs detected (e.g. sul) are associated to antibiotics used in aquaculture. - Several (74.2 %) strains studied were classified as pathogenic to human.V.S. has a Ph.D. fellowship granted by the FCT (Fundação para a
CiĂŞncia e a Tecnologia) with the reference SFRH/BD/133100/2017
cofinanced by European Social Fund and the Operational Program for
Human Capital (POCH), Portugal. This work was supported by funding
from the European Union’s Horizon 2020 Research and Innovation
programme under grant agreement No 773830: One Health European
Joint Programme (WORLDCOM project), and by FCT/MCTES [UIDB/
00211/2020] through national funds.info:eu-repo/semantics/publishedVersio
A EstatĂstica na Edição das Actas da Sociedade Portuguesa de EstatĂstica
As Actas da SPE, publicadas desde a realização do 1o Congresso, constituem
um importante veĂculo de divulgação da estatĂstica e da investigação cientĂ ca
e são um claro incentivo à publicação de artigos, em particular, por parte dos mais
jovens. Em ano jubilar e de debate da polĂtica editorial da SPE, pensamos que será de
grande utilidade analisar estatisticamente alguns dados relativos ao processo editorial,
não só para conhecimento da comunidade cientà ca mas também para apoio de futuras
Comissões Editoriais. Tendo por base os dados do XII Congresso da SPE, recorre-se a
diferentes ferramentas estatĂsticas para realizar comparações, procurar associações entre
diferentes variáveis e caracterizar o processo de revisão dos artigos, em particular,
ao nĂvel dos tempos de resposta de autores e avaliadores. Concluiremos apresentando
algumas ideias e sugestões para a melhoria do processo editorial
Land-cover patterns and hydrogeomorphology of tributaries: are these important stressors for the water quality of reservoirs in the Mediterranean region?
Four streams in the Guadiana watershed were followed up to assess hydrogeomorphological
and physicochemical characteristics, and to analyze its correlation with land use/land cover (LULC),
analyzing their possible influence in reservoir water quality and possible influence in the reservoir
water quality. The highest amounts of organic descriptors and nutrients were quantified in streams
with the major percentage of olive groves and vineyards and urban land cover classes. Streams more
influenced by agro-silvo-pastoral class presented better water quality, as this type of LULC acts as
a bu er of the contamination runo . The results highlighted that the hydrogeomorphology of the
streams may influence the transfer of pollutants loads to reservoirs. Hence, in intermittent streams
characterized by coarse particles in the sediment, high amounts of pollutants are accumulated when
the flow ceases, and are further transported to the reservoirs when the flow retakes. On the contrary,
streams with sediments characterized by a great percentage of fine particles and organic matter do not
induce so much stress in reservoirs, since these allow the adsorption of nutrients and trace elements,
without their transfer to reservoirsinfo:eu-repo/semantics/publishedVersio
- …