550 research outputs found
Impact of harvest residues, fertilisers and N-fixing plants on growth and nutritional status of young Eucalyptus globulus plantations under Mediterranean conditions
Growth and nutritional status of young plants
of Eucalyptus were assessed in a field trial, under different
scenarios of harvest residue management and nutrient
availability. Treatments were as follows: incorporation of
harvest residues into the soil by harrowing (I); I with N
fertiliser application (IF); I with leguminous, Lupinus
luteus L., seeding (IL); removal of harvest residues (R); R
with N fertiliser application (RF); R with leguminous
seeding (RL); distribution of harvest residues on the soil
surface (S); S with N fertiliser application (SF). Treatments
were replicated four times in four blocks with a fully
randomised design. Tree growth (height and diameter at
breast height) was measured and understory biomass
destructively recorded. Tree nutritional status was assessed
by foliar analysis (N, Ca, Mg, P, K and leaf area). Significant
differences in growth between I, R and S treatments
were only detected at early stage. Intercropping with
Lupinus decreased tree growth during the early phase, but
after 5 years growth was similar to that measured in the I
and R treatments. Application of fertiliser enhanced tree
growth especially when harvest residues were retained on
the soil surface. Combining incorporation of harvest residues
with fertiliser application (IF) was the best option to
increase tree growth, which was significantly greater than
in the R and S. Initially, leaf N was positively affected by
the leguminous (RL and IL), but, after the first fertiliser
application (1 year after planting), greater N was observed in the IF, RF and SF, the difference decreasing gradually
over the following year
Genetic diagnosis of familial hypercholesterolaemia: the importance of functional analysis of potential splice-site mutations
Familial hypercholesterolemia (FH) results from defective low-density lipoprotein receptor (LDLR) activity, mainly due to LDLR gene defects. Of the many different LDLR mutations found in patients with FH, about 6% of single base substitutions are located near or within introns, and are predicted to result in exon skipping, retention of an intron, or activation of cryptic sites during mRNA splicing. This paper reports on the Portuguese FH Study, which found 10 such mutations, 6 of them novel. For the mutations that have not been described before or those whose effect on function have not been analysed, their effect on splicing was investigated, using reverse transcriptase PCR analysis of LDLR mRNA from freshly isolated blood mononuclear cells. Two of these variants (c.313+6 T-->C, c.2389G-->T (p.V776L)) caused exon skipping, and one caused retention of an intron (c.1359-5C-->G), whereas two others (c.2140+5 G-->A and c.1061-8T-->C) had no apparent effect. Any effect of c.1185G-->C (p.V374V) on splicing could not be determined because it was on an allele with a promoter mutation (-42C-->G) that was probably not transcribed. Variants in four patients lost to follow-up could not be tested experimentally, but they almost certainly affect splicing because they disrupt the invariant AG or GT in acceptor (c.818-2A-->G) or donor (c.1060+1G-->A, c.1845+1delG and c.2547+1G-->A) spice sites. These findings emphasise that care must be taken before reporting the presence or absence of a splice-site mutation in the LDLR gene for diagnostic purposes. The study also shows that relatively simple, quick and inexpensive RNA assays can evaluate putative splicing mutations that are not always predictable by available software, thereby reducing genetic misdiagnosis of patients with FH
Potencial bioenergético dos resíduos orgânicos das florestas e da indústria aviária da região de Lafões
CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: A Associação de Desenvolvimento Rural de Lafões (ADRL, Portugal), entidade de gestão florestal e promotora desta pesquisa, desenvolve esforços que visam a adequada gestão dos resíduos originados na região. Na percussão de estratégias para uma gestão sustentável, definiu-se como objetivo numa primeira etapa o mapeamento dos resíduos da indústria aviária e das unidades de gestão florestal de Lafões. Utilizaram-se métodos baseados em Sistemas de Informação Geográfica, orientados por pressupostos metodológicos, referidos em bibliografia selecionada a partir de revisão bibliográfica, obtendo-se a quantidade anual em matéria seca, no que concerne à biomassa florestal. Quanto à biomassa dos aviários, optou-se pela recolha de dados junto das entidades regionais, seguindo as orientações metodológicas do IPCC e de outras entidades nacionais, estimando-se a sua quantidade anual em sólidos voláteis. Os valores obtidos foram 67 Mt VS/ano (60% da classe florestal eucalipto e 33% da pinheiro-bravo) e 69 Mt MS/ano (78 % da classe de aves frango) de biomassa florestal e dos aviários, respetivamente.ABSTRACT: The promoter of this research was the Lafões Rural Development Association (ADRL), a forest management entity, which counts waste management in the Lafões region as a concern. In the percussion of strategies for sustainable management, the objective of the first stage was to map the waste of the poultry industry and forest management units in the region. Geographic Information Systems based methods where applied, guided by methodological assumptions selected from a bibliographic review, obtaining their quantity in dry matter per year, with respect to forest biomass. With regard to the biomass from poultry industry, regional data was collected from local entities, following the methodological guidelines of the IPCC and national entities, obtaining their quantity in volatile solids per year. The values obtained were 67 Mt VS/year (60% of the eucalyptus forest class and 33% of Pinus pinaster) and 69 Mt MS/year (78% of the chicken poultry class), generated by the forest and the poultry industry, respectively.info:eu-repo/semantics/publishedVersio
Fauna de hidrozoários atecados (Hydrozoa, Anthoathecata) da costa do Estado do Ceará, Brasil
INFESTAÇÃO NATURAL DE Varroa jacobsoni EM Apis mellifera scutellata (HYMENOPTERA: APIDAE)
Varroa jacobsoni foi descrita em 1904 por Oldenans em Java em cria de Apis cerana. O
nível de infestação com V. jacobsoni mede indiretamente o grau de tolerância da A. mellifera à V.
jacobsoni. O estudo foi conduzido no Município de Mandirituba-PR. Os enxames foram capturados
com caixa iscas. A percentagem de infestação V. jacobsoni foi resistrada mensalmente. Aplicando-se
o teste de Friedman e usando-se o rank de cada colônia, separou-se os grupos de colônias
homogêneas. A tendência sazonal foi demostrada com representação gráfica. O experimento foi
delineado segundo blocos inteiramente casualizados. Em todas as amostras foi encontrado o ácaro
V. jacobsoni. Diferenças significativas entre as colônias foram observadas. Na população de Apis
mellifera scutellata existem três grupos homogêneos de colônias quanto ao nível de infestação com
esse ácaro. O inverno é a época onde o grau de infestação com V. jacobsoni é mais elevado.
Natural infestation of Apis mellifera scutellata (Hymenoptera; Apidae) by Varroa jacobsoni
(Mesostigmata; Varroidae)
Abstract
Infestation by Varroa jacobsoni in an offspring of Apis cerana was first described as
early as 1904 in Java. Since the level of infestation by V. jacobsoni may be an indirect procedure to
measure the Apis mellifera scutellata tolerance degree towards it, the present research was carried
out in order to evaluate such biological relationship between host and parasite and its implication in
the Apis mellifera scutellata productivity. This study was carried out at Mandirituba, Paraná, Brazil.
The swarms were captured with bait boxes. The percentage of V. jacobsoni infestation was
established monthly. According to the Friedman test ant through the rank, homogeneous colonies
were single out. The experiment has been delineated as entirely randomized blocks
Modelling the habitat preferences of the NE-Atlantic Sea cucumber Holothuria forskali : demographics and abundance
This work was funded by the Operational Program Mar2020 MAR-02.01.01-FEAMP-0052 “Newcumber - Avanços para o cultivo sustentável de pepinos do mar”. This work was also supported by national funds through FCT - Fundação para a Ciência e a Tecnologia, I.P., within the scope of the projects (https://doi.org/10.54499/UIDB/04292/2020, and https://doi.org/10.54499/UIDB/00006/2020) and the Associate Laboratory ARNET (https://doi.org/10.54499/LA/P/0069/2020), A.C. Brito with the Scientific Stimulus Program – CEECIND/00095/2017, A.P. with the under the Scientific Employment Stimulus - Institutional Call - CEECINST/00051/2018 and Francisco Azevedo e Silva and João Trigo de Sousa through the individual grants (SFRH/BD/09563/2020 and SFRH/BDANA/02949/2023).Sea cucumbers' historical demand, together with the depletion of several traditional species in the market, has popularized new target species from new fishing grounds. Holothuria forskali is one of those emergent species in the trade market. However, it is a species for which there is no relevant information to allow sustainable stock management. Fundamental knowledge of the populations' structure and habitat preferences are key elements without which any measure is inconsequent. This work aims to fill that gap by modelling temporal and spatial patterns of abundance and demographic structure of this species in a NE-Atlantic area, as a function of environmental features. For a period of 15 months, nine regular sampling campaigns collected data on density, individual length, individual conditions of occurrence (e.g. sheltered, on sand, on algae cover) and environmental parameters (water column, sediment, substrate cover and type), using random transects throughout a costal rocky-reef, considering habitat heterogeneity and substrate types. To determine the species' habitat preferences Generalized Linear Models were used to model density and demographic structure of the species as a function of environmental conditions. The models revealed that the main drivers shaping the distribution of H. forskali are neither abiotic nor biotic parameters of the water column, but physical stressors, like current intensity and depth, and substrate type in a patchy distribution pattern. Estuarine conditions are generally avoided, although with a size-dependent opportunistic strategy. Larger individuals show temporal and spatial displacement patterns towards suitable reproductive conditions (pre-breeding aggregation) and favourable feeding grounds and smaller size-classes tend to aggregate in higher numbers in more stable environments. Sustainable sources for market supply, like aquaculture, are still a long way from commercial production. So, these results are fundamental to support effective conservation measures for stock management of H. forskaliPublisher PDFPeer reviewe
Allometric relationships to assess ontogenetic adaptative changes in three NE Atlantic commercial sea cucumbers (Echinodermata, Holothuroidea)
This study was financed by the Operational Program Mar2020 nº MAR-02.01.01-FEAMP-0052 “Newcumber—Avanços para o cultivo sustentável de pepinos-do-mar”. It received further financial support from Fundação para a Ciência e a Tecnologia with project UIDB/04292/2020; A.C. Brito and A. Pombo through the Scientific Employment Stimulus Programmes (CEECIND/00095/2017 and CEECINST/00051/2018); and Francisco Azevedo e Silva through the individual research Grant 2020.09563.BD; Also, T. A. Marques and C. Rocha thank partial support by CEAUL (funded by FCT—Fundação para a Ciência e a Tecnologia, Portugal, through the project UIDB/00006/2020).Holothuria arguinensis, Holothuria mammata and Holothuria forskali are three common sea cucumber species found in the NE Atlantic, traded in international markets and susceptible to capture. Allometric relationships reveal if the scaling relationships between biometric characters are proportional with growth, being a useful tool to understand species growth strategies. Allometric relationships of the three species were estimated and compared between them and with populations from different regions. These allometric relationships revealed that the three species have negative allometric growth. However, they have different growth strategies between them and reveal different regional intra-specific growth strategies when compared to other populations, suggesting ontogenetic adaptation as a consequence of external factors. PostprintPeer reviewe
Noise modeling and variance stabilization of a computed radiography (CR) mammography system subject to fixed-pattern noise
In this work we model the noise properties of a computed radiography (CR) mammography system by adding an extra degree of freedom to a well-established noise model, and derive a variance-stabilizing transform (VST) to convert the signal-dependent noise into approximately signal-independent. The proposed model relies on a quadratic variance function, which considers fixed-pattern (structural), quantum and electronic noise. It also accounts for the spatial-dependency of the noise by assuming a space-variant quantum coefficient. The proposed noise model was compared against two alternative models commonly found in the literature. The first alternative model ignores the spatial-variability of the quantum noise, and the second model assumes negligible structural noise. We also derive a VST to convert noisy observations contaminated by the proposed noise model into observations with approximately Gaussian noise and constant variance equals to one. Finally, we estimated a look-up table that can be used as an inverse transform in denoising applications. A phantom study was conducted to validate the noise model, VST and inverse VST. The results show that the space-variant signal-dependent quadratic noise model is appropriate to describe noise in this CR mammography system (errors< 2.0% in terms of signal-to-noise ratio). The two alternative noise models were outperformed by the proposed model (errors as high as 14.7% and 9.4%). The designed VST was able to stabilize the noise so that it has variance approximately equal to one (errors< 4.1%), while the two alternative models achieved errors as high as 26.9% and 18.0%, respectively. Finally, the proposed inverse transform was capable of returning the signal to the original signal range with virtually no bias.acceptedVersionPeer reviewe
cis-Acting Complex-Trait-Associated lincRNA Expression Correlates with Modulation of Chromosomal Architecture.
Intergenic long noncoding RNAs (lincRNAs) are the largest class of transcripts in the human genome. Although many have recently been linked to complex human traits, the underlying mechanisms for most of these transcripts remain undetermined. We investigated the regulatory roles of a high-confidence and reproducible set of 69 trait-relevant lincRNAs (TR-lincRNAs) in human lymphoblastoid cells whose biological relevance is supported by their evolutionary conservation during recent human history and genetic interactions with other trait-associated loci. Their enrichment in enhancer-like chromatin signatures, interactions with nearby trait-relevant protein-coding loci, and preferential location at topologically associated domain (TAD) boundaries provide evidence that TR-lincRNAs likely regulate proximal trait-relevant gene expression in cis by modulating local chromosomal architecture. This is consistent with the positive and significant correlation found between TR-lincRNA abundance and intra-TAD DNA-DNA contacts. Our results provide insights into the molecular mode of action by which TR-lincRNAs contribute to complex human traits
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