396 research outputs found
Biological interactions between nematophagous fungi, Esteya spp., and the pinewood nematode, Bursaphelenchus xylophilus
The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a quarantine organism in several countries and the causal agent of pine wilt disease (PWD), a serious threat to pine forests worldwide. PWD results from complex interactions between the nematode, its insect vector, Monochamus spp., and host plants (conifers), being the nematode the common element in this interaction. The PWN is considered the sixth most economically important plant-parasitic nematode. In Europe, this pest was first reported in Portugal in 1999, in maritime pine, Pinus pinaster. Due to its economic importance and worldwide distribution, an enormous amount of effort is devoted to research on B. xylophilus and PWD. Scenarios strongly suggest that climate change is likely going to cause a spread of PWD and outbreaks in areas free of the disease. The urgent need for sustainable management strategies has led to an increasing interest in antagonists capable of suppressing the PWN. Nematophagous fungi belonging to the Esteya genus are reported as natural enemies of the PWN and promising biocontrol agents. There are currently two described species: E. vermicola and E. floridanum, the first of which is capable of mimicking volatile organic compounds produced naturally by Pinus spp. in order to attract PWN. However, few studies have been carried out on the development of Esteya spp. inside pine trees, and none using maritime pine, the main and most affected species in Portuguese forests and its largest carbon reservoir. It is therefore crucial to understand the plant-nematode-fungus interactions between P. pinaster, B. xylophilus and Esteya spp. In this sense, biological interactions between these two antagonists, the PWN and P. pinaster were investigated, namely fungus-fungus, fungus-nematode and fungus-tree, as well as feeding trials and chemotaxis assays, to determine the attractive power of both fungal species. These results will enlighten us on the most promising species for biocontrol and help us devise new ways to manage PWD
Profiling mycobiota communities associated with the Pine Wilt Disease
Pine wilt Disease (PWD) is one of the most
damaging diseases for conifer forests worldwide.
This complex disease involves the interaction
between three primary biological elements - the
pinewood nematode (PWN) Bursaphelenchus
xylophilus, the insect-vector Monochamus sp.,
and the host tree Pinus spp. – and other
secondary elements such as endophytic bacteria
and fungi. The development of B. xylophilus is
strongly associated with fungi that colonize the
declining trees, with special impact in their
reproduction and number of individuals carried by
the vector. In light of previous knowledge, we are focused in
obtaining a detailed characterization of the
structure and dynamics of the nematode-fungi
interactions. Using the ITS2 amplicon-based
metagenomic approach, we compared the fungal
communities from PWN infected and non-infected
P. pinaster trees collected in two distint study
sites, Tróia (location where PWN was first
detected in 1999) and Seia (northwestern of
Portugal)
Três rearranjos diferentes, três fenótipos diferentes :Estudo Familiar Cromossoma 14
Introdução – Cromossomas derivativos são o resultado de rearranjos estruturais que
tanto podem ocorrer num só, como entre dois ou mais cromossomas. Estes rearranjos
dão origem a cromossomas estruturalmente anormais, podendo resultar um fenótipo
normal ou mais ou menos grave, dependendo do tipo de anomalia encontrada.
Materiais e métodos – Caso Ãndex: homem de 55 anos, referenciado para estudos de
citogenética clássica (cariótipo com bandas GTG de alta resolução) e molecular
(MLPA – kits P036 e P070 e FISH com sonda subtelomérica especifica para o
cromossoma 14) por apresentar um quadro clÃnico de atraso mental. Posteriormente
realizaram-se estudos citogenéticos a uma irmã com atraso cognitivo e baixa estatura,
e a mais quatro familiares com fenótipos normais.
Resultados – O cariótipo do caso Ãndex revelou a existência de uma anomalia
cromossómica estrutural desequilibrada num dos cromossomas 14, sugerindo uma
deleção da banda 14q32, e uma duplicação do braço curto localizada na parte terminal
do braço longo. Nos estudos de citogenética molecular, a técnica de MLPA identificou
uma deleção da região subtelomérica no braço longo do cromossoma 14, em ambos
os kits e, posteriormente, a técnica de FISH comprovou essa deleção.
Após estudos familiares, concluiu-se que dois dos irmãos apresentavam anomalias
cromossómicas distintas do caso Ãndex, envolvendo igualmente o cromossoma 14.
Apesar de não ser possÃvel efetuar o cariótipo à mãe (falecida), presume-se que estas
alterações tenham tido origem numa anomalia cromossómica materna, uma vez que o
pai deste indivÃduo apresentava um cariótipo normal.
Conclusões – Os autores apresentam os resultados citogenéticos dos vários
indivÃduos estudados, e realçam a raridade da existência de três rearranjos diferentes
(um deles aparentemente equilibrado e dois desequilibrados), envolvendo o
cromossoma 14, encontrados numa mesma famÃlia
Identifying Variability in Process Performance Indicators
The performance perspective of business processes is concerned
with the definition of performance requirements usually specified
as a set of Process Performance Indicators (PPIs). Like other business
process perspectives such as control-flow or data, there are cases in which
PPIs are subject to variability. However, although the modelling of business
process variability (BPV) has evolved significantly, there are very
few contributions addressing the variability in the performance perspective
of business processes. Modelling PPI variants with tools and techniques
non-suitable for variability may generate redundant models, thus
making it difficult its maintenance and future adaptations, also increasing
possibility of errors in its managing. In this paper we present different
cases of PPI variability detected as result of the analysis of several
processes where BPV is present. Based on an existent metamodel used
for defining PPIs over BPs, we propose its formal extension that allows
the definition of PPI variability according to the cases identified.Ministerio de EconomÃa y Competitividad TIN2015-70560-RJunta de AndalucÃa P12-TIC-1867Junta de AndalucÃa P10-TIC-590
Block of NMDA receptor channels by endogenous neurosteroids: implications for the agonist induced conformational states of the channel vestibule
N-methyl-D-aspartate receptors (NMDARs) mediate synaptic plasticity, and their dysfunction is implicated in multiple brain disorders. NMDARs can be allosterically modulated by numerous compounds, including endogenous neurosteroid pregnanolone sulfate. Here, we identify the molecular basis of the use-dependent and voltage-independent inhibitory effect of neurosteroids on NMDAR responses. The site of action is located at the extracellular vestibule of the receptor's ion channel pore and is accessible after receptor activation. Mutations in the extracellular vestibule in the SYTANLAAF motif disrupt the inhibitory effect of negatively charged steroids. In contrast, positively charged steroids inhibit mutated NMDAR responses in a voltage-dependent manner. These results, in combination with molecular modeling, characterize structure details of the open configuration of the NMDAR channel. Our results provide a unique opportunity for the development of new therapeutic neurosteroid-based ligands to treat diseases associated with dysfunction of the glutamate system
The Portfolio as an Evaluation Tool: an Analysis of its Use in an Undergraduate Nursing Program
This qualitative study was carried out between April and August 2007. It analyzed the use of portfolios in the academic community. A total of nine full-time professors and 119 students enrolled in their third semester were interviewed through a semi-structured interview. Content analysis was used to analyze data. Learning evaluations are seen as a verification of knowledge and efficacy of pedagogical method, and also as an incentive to study. Evaluations are procedural, that is, evaluation is continuous, or one-time, e.g. semester end tests. The portfolio is defined as a gradual and continuous evaluation tool. The faculty members and students need to accept the use of portfolios and evaluate the possibilities of this resource. This study is a first attempt to appraise the evaluation process of an undergraduate program, and the use of portfolios and other strategies needs to be consolidated in order to improve the educational process in undergraduate nursing programs.Se trata de un estudio cualitativo, realizado en el perÃodo de abril a agosto de 2007. El objetivo fue analizar la utilización del portafolio por la comunidad académica. Se entrevistó a través de un guión a nueve docentes efectivos y 119 discentes matriculados a partir del tercer perÃodo. En el análisis de datos se utilizó el análisis de contenido. La evaluación del aprendizaje es considerada como verificación del conocimiento, como eficacia del método pedagógico e incentivo al estudio. Con relación al tipo de evaluación son procesuales y puntuales. El portafolio es definido como un instrumento de evaluación gradual y continuo. Es necesario que el cuerpo docente y discente acepte experimentar la utilización del portafolio y asà evaluar las posibilidades de este recurso. Representa una primera aproximación al proceso de evaluación en la graduación y de esa forma el portafolio y otras estrategias necesitan ser consolidadas de forma a mejorar el proceso de formación en la graduación de enfermerÃa.Este é um estudo qualitativo, realizado no perÃodo de abril a agosto de 2007. O objetivo foi analisar a utilização do portfólio pela comunidade acadêmica. Entrevistaram-se, através de um roteiro, nove docentes efetivos e 119 discentes matriculados a partir do terceiro perÃodo. Na análise de dados utilizou-se da análise de conteúdo. A avaliação da aprendizagem é considerada como verificação do conhecimento, como eficácia do método pedagógico e incentivo ao estudo. Com relação aos tipos de avaliação são eles processuais e pontuais. O portfólio é definido como instrumento de avaliação gradual e contÃnuo. É necessário que o corpo docente e discente aceite experimentar a utilização do portfólio e assim avaliar as possibilidades desse recurso. Representa a primeira aproximação ao processo de avaliação na graduação e, dessa forma, o portfólio e outras estratégias precisam ser consolidadas de forma a melhorar o processo de formação na graduação de enfermagem
The Effect of Macular Hole Duration on Surgical Outcomes: An Individual Participant Data Study of Randomized Controlled Trials
Topic: To define the effect of symptom duration on outcomes in people undergoing surgery for idiopathic full-thickness macular holes (iFTMHs) by means of an individual participant data (IPD) study of randomized controlled trials (RCTs). The outcomes assessed were primary iFTMH closure and postoperative best-corrected visual acuity (BCVA). Clinical Relevance: Idiopathic full-thickness macular holes are visually disabling with a prevalence of up to 0.5%. Untreated BCVA is typically reduced to 20/200. Surgery can close holes and improve vision. Symptom duration is thought to affect outcomes with surgery, but the effect is unclear. Methods: A systematic review identified eligible RCTs that included adults with iFTMH undergoing vitrectomy with gas tamponade in which symptom duration, primary iFTMH closure, and postoperative BCVA were recorded. Bibliographic databases were searched for articles published between 2000 and 2020. Individual participant data were requested from eligible studies. Results: Twenty eligible RCTs were identified. Data were requested from all studies and obtained from 12, representing 940 eyes in total. Median symptom duration was 6 months (interquartile range, 3–10). Primary closure was achieved in 81.5% of eyes. There was a linear relationship between predicted probability of closure and symptom duration. Multilevel logistic regression showed each additional month of duration was associated with 0.965 times lower odds of closure (95% confidence interval [CI], 0.935–0.996, P = 0.026). Internal limiting membrane (ILM) peeling, ILM flap use, better preoperative BCVA, face-down positioning, and smaller iFTMH size were associated with increased odds of primary closure. Median postoperative BCVA in eyes achieving primary closure was 0.48 logarithm of the minimum angle of resolution (logMAR) (20/60). Multilevel logistic regression showed for eyes achieving primary iFTMH closure, each additional month of symptom duration was associated with worsening BCVA by 0.008 logMAR units (95% CI, 0.005–0.011, P < 0.001) (i.e., ∼1 Early Treatment Diabetic Retinopathy Study letter loss per 2 months). ILM flaps, intraocular tamponade using long-acting gas, better preoperative BCVA, smaller iFTMH size, and phakic status were also associated with improved postoperative BCVA. Conclusions: Symptom duration was independently associated with both anatomic and visual outcomes in persons undergoing surgery for iFTMH. Time to surgery should be minimized and care pathways designed to enable this
Visual Associative Learning in Restrained Honey Bees with Intact Antennae
A restrained honey bee can be trained to extend its proboscis in response to the pairing of an odor with a sucrose reward, a form of olfactory associative learning referred to as the proboscis extension response (PER). Although the ability of flying honey bees to respond to visual cues is well-established, associative visual learning in restrained honey bees has been challenging to demonstrate. Those few groups that have documented vision-based PER have reported that removing the antennae prior to training is a prerequisite for learning. Here we report, for a simple visual learning task, the first successful performance by restrained honey bees with intact antennae. Honey bee foragers were trained on a differential visual association task by pairing the presentation of a blue light with a sucrose reward and leaving the presentation of a green light unrewarded. A negative correlation was found between age of foragers and their performance in the visual PER task. Using the adaptations to the traditional PER task outlined here, future studies can exploit pharmacological and physiological techniques to explore the neural circuit basis of visual learning in the honey bee
- …