20 research outputs found
Can Greater Flamingo Recognize Fertile <i>vs.</i> Infertile Egg? A Single Case Study
Fertility of captive flamingos varies between flocks, species and seasons. Individuating
infertile eggs could be helpful to facilitate important decisions. Wild
animals could be encouraged to abandon the nest or not, whereas in captivity
removing non-viable egg would lead birds to lay a new one. The aim of this
study was to investigate the parental behaviour of a pair of greater flamingos
(Phoenicopterus roseus ) in the presence of a fertile and an infertile egg. Data
on the posture and behaviours of the pair on the nest were collected over two
different periods: first period\u2014an infertile egg was laid; second period\u2014a fertile
egg was laid. For each period, 28 ten-minute sessions per flamingo partner
were run. Results revealed that female flamingo spent significantly more time
standing on the nest in the first than in the second period (P = 0.010). Moreover,
when standing on the nest, the female performed significantly more
egg-care behaviour (attention to the egg, egg rotation/moving) in the first
than in the second period (P = 0.010). No significant differences between periods
emerged in the male flamingo posture on the nest and behaviours.
Findings from this study suggest that female flamingos stand on the nest
longer if the egg is infertile, paying more attention and examining it deeply.
This study provides new insights into greater flamingo parent-embryo communication.
Future research is needed to improve our knowledge on this topic,
as well as on the husbandry of this species in the controlled environment
what does early mean remarks on immediate prosthetic vascular access cannulation for urgent hemodialysis
Management of complicated vascular access. A step-by-step description of a case of hyperkalemia and vascular access failure in a patient receiving maintenance hemodialysis treated for numerous prev..
SARS-CoV-2 RNA identification in nasopharyngeal swabs: issues in pre-analytics.
Abstract
Objectives
The direct identification of SARS-CoV-2 RNA in nasopharyngeal swabs is recommended for diagnosing the novel COVID-19 disease. Pre-analytical determinants, such as sampling procedures, time and temperature storage conditions, might impact on the end result. Our aim was to evaluate the effects of sampling procedures, time and temperature of the primary nasopharyngeal swabs storage on real-time reverse-transcription polymerase chain reaction (rRT-PCR) results.
Methods
Each nasopharyngeal swab obtained from 10 hospitalized patients for COVID-19 was subdivided in 15 aliquots: five were kept at room temperature; five were refrigerated (+4 °C); five were immediately mixed with the extraction buffer and refrigerated at +4 °C. Every day and for 5 days, one aliquot per condition was analyzed (rRT-PCR) for SARS-CoV-2 gene E and RNaseP and threshold cycles (Ct) compared. To evaluate manual sampling, 70 nasopharyngeal swabs were sampled twice by two different operators and analyzed separately one from the other.
Results
A total of 6/10 swabs were SARS-CoV-2 positive. No significant time or storage-dependent variations were observed in SARS-CoV-2 Ct. Re-sampling of swabs with SARS-CoV-2 Ct lower than 33 resulted in highly reproducible results (CV=2.9%), while a high variability was observed when Ct values were higher than 33 (CV=10.3%).
Conclusions
This study demonstrates that time and temperature of nasopharyngeal swabs storage do not significantly impact on results reproducibility. However, swabs sampling is a critical step, and especially in case of low viral load, might be a potential source of diagnostic errors
Cell surface nucleolin interacts with and internalizes Bothrops asper Lys49 phospholipase A2 and mediates its toxic activity
Phospholipases A2 are a major component of snake venoms. Some of them cause severe muscle necrosis
through an unknown mechanism. Phospholipid hydrolysis is a possible explanation of their toxic action,
but catalytic and toxic properties of PLA2s are not directly connected. In addition, viperid venoms
contain PLA2-like proteins, which are very toxic even if they lack catalytic activity due to a critical
mutation in position 49. In this work, the PLA2-like Bothrops asper myotoxin-II, conjugated with the
fluorophore TAMRA, was found to be internalized in mouse myotubes, and in RAW264.7 cells. Through
experiments of protein fishing and mass spectrometry analysis, using biotinylated Mt-II as bait, we
found fifteen proteins interacting with the toxin and among them nucleolin, a nucleolar protein present
also on cell surface. By means of confocal microscopy, Mt-II and nucleolin were shown to colocalise, at
4 °C, on cell membrane where they form Congo-red sensitive assemblies, while at 37 °C, 20 minutes after
the intoxication, they colocalise in intracellular spots going from plasmatic membrane to paranuclear
and nuclear area. Finally, nucleolin antagonists were found to inhibit the Mt-II internalization and toxic
activity and were used to identify the nucleolin regions involved in the interaction with the toxinUniversidad de Costa Rica/[741-B4-100]/UCR/Costa RicaUniversidad de Costa Rica/[741-B5-602]/UCR/Costa RicaInternational Center for Genetic Engineering and Biotechnology/[CRP/13/006]/ICGEB/IndiaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí
Overview on electrical issues faced during the SPIDER experimental campaigns
SPIDER is the full-scale prototype of the ion source of the ITER Heating
Neutral Beam Injector, where negative ions of Hydrogen or Deuterium are
produced by a RF generated plasma and accelerated with a set of grids up to
~100 keV. The Power Supply System is composed of high voltage dc power supplies
capable of handling frequent grid breakdowns, high current dc generators for
the magnetic filter field and RF generators for the plasma generation. During
the first 3 years of SPIDER operation different electrical issues were
discovered, understood and addressed thanks to deep analyses of the
experimental results supported by modelling activities. The paper gives an
overview on the observed phenomena and relevant analyses to understand them, on
the effectiveness of the short-term modifications provided to SPIDER to face
the encountered issues and on the design principle of long-term solutions to be
introduced during the currently ongoing long shutdown.Comment: 8 pages, 12 figures. Presented at SOFT 202
Accurate Human Papillomavirus Genotyping by 454 Pyrosequencing
Accurate HPV typing is essential for evaluation and monitoring HPV vaccines, as second line testing in cervical cancer screening, and in epidemiological surveys. In this study, we set up and assessed in clinical samples a new HPV typing method based on 454 next-generation sequencing (NGS) of HPV L1 amplicons, generated by using a modified PGMY primer set with improved sensitivity for some HPV types that are not targeted by standard PGMY primers. By using a median 12,800-fold coverage, the NGS method allowed to correctly identify all high-risk HPV types, either in single and multiple infection, with a sensitivity of 50 genome equivalents, as demonstrated by testing WHO LabNet EQA sample panels. Analysis of mixtures of HPV16- and HPV18-positive cell lines demonstrated that the NGS method could reproducibly quantify the proportion of each HPV type in multiple infections in a wide dynamic range. Testing of HPV-positive clinical samples showed that NGS could correctly identify a high number of HPV types in multiple infections. The NGS method was also effective in the analysis of a set of cervical specimens with discordant results at hybrid capture 2 and line probe assays. In conclusion, a new HPV typing method based on 454 pyrosequencing was set up. This method was sensitive, specific, quantitative, and precise in both single and multiple infections. It could identify a wide range of HPV types and might potentially discover new HPV types
Hen egg white lysozyme is a hidden allergen in Italian commmercial ciders
none6noHen egg white lysozyme (HEWL) is an enzyme used in alcoholic fermentations for its ability to control the growth of Gram-positive bacteria and spoilage bacteria, without inhibiting yeast growth, and it allows reducing the use of sulphur dioxide. Nevertheless, considering the potential allergenicity of this protein, the presence of HEWL should be declared on the label of the final product. In this work, we analysed 18 commercial Italian ciders by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), and found traces of HEWL in 12 samples without label declaration. We used western blot and Enzyme-linked Immunosorbent Assay (ELISA) to verify the immunological activity of HEWL, and to quantify its content in the ciders. Two out of 18 samples resulted positive both to Immunoblot and ELISA. Our results indicate the requirement of a more stringent control of the commercial ciders and the need of label declaration for ciders treated with such compounds.mixedMainente, Federica; Pasini, Gabriella; Simonato, Barbara; Arrigoni, Giorgio; Franchin, Cinzia; Rizzi CorradoMainente, Federica; Pasini, Gabriella; Simonato, Barbara; Arrigoni, Giorgio; Franchin, Cinzia; Rizzi, Corrad