291 research outputs found
Bioactivity of Monoterpene Alcohols as an Indicator of Biopesticidal Essential Oils against the Root Knot Nematode Meloidogyne ethiopica
The application of pesticides remains one of the most efficient control methods for phytophagous
parasites in crops. Essential oils (EOs) are complex mixtures of highly active compounds
that can be used as biopesticides against plant parasitic nematodes. In the present work, the antinematodal
activity of the monoterpene alcohols geraniol, linalool, menthol or -terpineol, which are
generally found in high amounts in EOs of some aromatic and medicinal plants, was analyzed on
the root knot nematode Meloidogyne ethiopica. Geraniol showed intense and lasting antinematodal
activity, suggesting that EOs rich in this compound can be used in the development of nematicidal
biopesticides to integrate sustainable pest management strategies against this pest
Diagnóstico de Cryptosporidium spp. por meio de nested-PCR em caprinos jovens de Quixadá, Ceará.
Bayesian Bootstrap Inference for the ROC Surface
Accurate diagnosis of disease is of great importance in clinical practice and
medical research. The receiver operating characteristic (ROC) surface is a
popular tool for evaluating the discriminatory ability of continuous diagnostic
test outcomes when there exist three ordered disease classes (e.g., no disease,
mild disease, advanced disease). We propose the Bayesian bootstrap, a fully
nonparametric method, for conducting inference about the ROC surface and its
functionals, such as the volume under the surface. The proposed method is based
on a simple, yet interesting, representation of the ROC surface in terms of
placement variables. Results from a simulation study demonstrate the ability of
our method to successfully recover the true ROC surface and to produce valid
inferences in a variety of complex scenarios. An application to data from the
Trail Making Test to assess cognitive impairment in Parkinson's disease
patients is provided
Fungal communities of the Pine Wilt Disease Complex: Studying the Interaction of Ophiostomatales with Bursaphelenchus xylophilus
Considered one of the most devastating plant–parasitic nematodes worldwide,
Bursaphelenchus xylophilus (commonly known as pinewood nematode, PWN) is the
causal agent of the pine wilt disease in the Eurasian coniferous forests. This migratory
parasitic nematode is carried by an insect vector (Monochamus spp.) into the host
tree (Pinus species), where it can feed on parenchymal cells and reproduce massively,
resulting in the tree wilting. In declining trees, PWN populations are strongly dependent
on fungal communities colonizing the host (predominantly ophiostomatoid fungi known
to cause sapwood blue-staining, the blue-stain fungi), which not only influence their
development and life cycle but also the number of individuals carried by the insect vector
into a new host. Our main aim is to understand if PWN-associated mycobiota plays a
key role in the development of PWD, in interaction with the PWN and the insect vector,
and to what extent it can be targeted to disrupt the disease cycle. For this purpose, we
characterized the fungal communities of Pinus pinaster trees infected and non-infected
with PWN in three collection sites in Continental Portugal with different PWD temporal
incidences. Our results showed that non-infected P. pinaster mycoflora is more diverse
(in terms of abundance and fungal richness) than PWN-infected pine trees in the most
recent PWD foci, as opposed to the fungal communities of long-term PWD history
sites. Then, due to their ecological importance for PWN survival, representatives of the
main ophiostomatoid fungi isolated (Ophiostoma, Leptographium, and Graphilbum) were
characterized for their adaptative response to temperature, competition in-between taxa,
and as food source for PWN. Under the conditions studied, Leptographium isolates
showed promising results for PWN control. They could outcompete the other species,
especially O. ips, and significantly reduce the development of PWN populations when
compared to Botrytis cinerea (routinely used for PWN lab culturing), suggesting this to
be a natural antagonist not only for the other blue-stain species but also for the PWN
Epidemiologia da Infeção por Clostridioides Difficile em Portugal: um Estudo Retrospetivo, Observacional em Doentes Hospitalizados
Introduction: Clostridioides difficile is the main cause of healthcare-associated diarrhea in Europe and North America. The aim of this study was to characterize the epidemiology and clinical burden of Clostridioides difficile infection among hospitalized patients in Portugal.
Material and methods: Retrospective study conducted in six public hospital centers in Portugal. All primary Clostridioides difficile infection episodes and related recurrences occurring in 2017, as well as episodes developing two to eight weeks after the last episode diagnosed in that year, were documented. The National Reference Laboratory (National Institute of Health Dr. Ricardo Jorge) provided national surveillance data on Clostridioides difficile infection.
Results: A total of 385 inpatients with at least one primary episode diagnosed in 2017 were included. Most patients were aged over 70 years-old (73.2%). The included patients developed 451 episodes during the observation period. Approximately 44% of primary episodes were community-associated. Most episodes (94.9%) occurred in patients with one or more risk factors, with recent antibiotic exposure being particularly common (86.0%). All-cause in-hospital mortality was 19.5%, being significantly higher in patients aged over 65 years-old versus those aged 18 to 64 years-old (22.4% vs 7.8%, respectively). Over 50 different ribotypes were observed among 206 Clostridioides difficile strains received by the National Reference Laboratory.
Conclusion: In Portugal, hospitalized patients with Clostridioides difficile infection are mostly older patients presenting risk factors for the development of this infection, particularly recent antibiotic exposure. Mortality is disproportionately high among the older population. Community-associated Clostridioides difficile infection is common among inpatients with this infection.info:eu-repo/semantics/publishedVersio
Extracellular electrophysiological measurements of cooperative signals in astrocytes populations
Astrocytes are neuroglial cells that exhibit functional electrical properties sensitive to neuronal activity and capable of modulating neurotransmission. Thus, electrophysiological recordings of astroglial activity are very attractive to study the dynamics of glial signaling. This contribution reports on the use of ultra-sensitive planar electrodes combined with low noise and low frequency amplifiers that enable the detection of extracellular signals produced by primary cultures of astrocytes isolated from mouse cerebral cortex. Recorded activity is characterized by spontaneous bursts comprised of discrete signals with pronounced changes on the signal rate and amplitude. Weak and sporadic signals become synchronized and evolve with time to higher amplitude signals with a quasi-periodic behavior, revealing a cooperative signaling process. The methodology presented herewith enables the study of ionic fluctuations of population of cells, complementing the single cells observation by calcium imaging as well as by patch-clamp techniques.Portuguese Foundation for Science and Technology (FCT) [PTDC/EEI-AUT/5442/2014]; Instituto de Telecomunicacoes [UID/Multi/04326/2013]; Associated Laboratory - Institute of Nanoscience and Nanotechnology [POCI-01-0145-FEDER-016623]; [PTDC/CTM-NAN/3146/2014]info:eu-repo/semantics/publishedVersio
Caracterização molecular de Cryptosporidium spp. em caprinos jovens de propriedades rurais de Quixadá, Ceará.
Surveillance of mother-to-child HIV transmission: socioeconomic and health care coverage indicators
Pineapple (Ananas comosus) cv. pérola ex vitro growth and mycorrhizal colonization affected by in vitro sucrose concentration
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