8 research outputs found
A guide to the identification of common blue-green algae (Cyanoprokaryotes) in Australian freshwaters
Blue-green algae (Cyanophyta) or cyanobacteria are prokaryotic phototrophic organisms. They have traditionally been classified with algae under the International Code of Botanical Nomenclature
Disaggregation of colonies of Microcystis (Cyanobacteria) : efficiency of two techniques assessed using an image analysis system
Disaggregation of colonies of Microcystis (Cyanobacteria) into smaller aggregates or single cells is a useful process for improving the accuracy and precision of cell abundance estimates in natural populations. An image analysis system was therefore used to assess the efficiency of two techniques, heating/vortexing and grinding, for disaggregating fixed and live colonies. Eight environmental samples, consisting of either colonial or non-colonial strains, were tested in time course experiments using each technique by analysing the number and total area of the objects (i.e., cells, clumps of cells, colonies) acquired. The results show that i) image analysis is an efficient tool to compare the efficiency of disaggregation techniques on colonies of cyanobacteria, ii) the grinding technique is more efficient in disaggregating all types of Microcystis colony, without significant loss, and iii) the heating technique does not work for all types of colonies, in particular, compact colonies fixed with Lugol’s iodine solution
Application of an image analysis system to enumerate and measure cyanobacteria
"Cyanobacteria, also known as blue-green algae, are the most notorious bloom formers in freshwater environments. Their success is due to their ability to adapt their physiological capacities to compete with other phytoplankton species (e.g., for light and nutrients, Padisák 1997), and the fact that they seem less edible for zooplankton and fish than other non-blooming algae (Gilbert 1996; Reynolds 1998). Cyanobacteria are photosynthetic, oxygen-producing and nitrogen-fixing prokaryotic organisms. They are characterized by the presence of the accessory pigment phycobilin. There are three basic morphological groups: 1) unicells, which may be solitary or aggregated in colonies; 2) undifferentiated non-heterocyst filaments, which also may be solitary or aggregated; and 3) filamentous forms with differentiated cells called heterocysts (Paerl et al. 2001). As a result of increasing environmental stress on freshwater ecosystems (e.g., eutrophication), blooms are increasing in number and frequency world-wide. Besides health problems due to their toxicity (such as the Caruaru tragedy in Pernambuco state, Brazil, Azevedo 1996), and environmental problems (e.g. fish kills and food web alterations), such blooms may also give rise to water quality and engineering problems such as clogging of filters in water treatment works, coloration of the water or production of tastes and odours (Paerl et al. 2001)."--p. 10
The Late Antique and Early Medieval Habitat and Church on the Monte S. Martino, Riva Del Garda district, North Italy
The Late Antique and Early Medieval Habitat and Church on the Monte S. Martino, Riva Del Garda district, North Ital
Ego-resilience and psychological wellness in rural communities
Resilience in the context of rural communities is defined as the capacity to move through and beyond adversity. The literature recognises that rural people suffer particular stressors: high exposure to global economic pressures and government policy changes; droughts, floods and other extreme weather conditions; and the challenges of keeping a farm financially viable and family intact. Owing to the necessities of survival in "the bush", rural people tend to be stoic and self-reliant and therefore reluctant to seek help except in dire emergencies. Rural men have been shown to draw on inner strengths to regain control after difficult experiences, along with using formal and social supports, and strategies such as taking breaks. Individual and community resilience are mutually supportive and researchers argue that balanced social and economic development is needed to enhance resilience and wellbeing in rural areas, in addition to improved access to mental health and other health services. © 2011 by Nova Science Publishers, Inc. All rights reserved
Fully Automated Trimethylsilyl (TMS) Derivatisation Protocol for Metabolite Profiling by GC-MS
Gas Chromatography-Mass Spectrometry (GC-MS) has long been used for metabolite
profiling of a wide range of biological samples. Many derivatisation protocols are already available
and among these, trimethylsilyl (TMS) derivatisation is one of the most widely used in metabolomics.
However, most TMS methods rely on off-line derivatisation prior to GC-MS analysis. In the case
of manual off-line TMS derivatisation, the derivative created is unstable, so reduction in recoveries
occurs over time. Thus, derivatisation is carried out in small batches. Here, we present a fully
automated TMS derivatisation protocol using robotic autosamplers and we also evaluate a commercial
software, Maestro available from Gerstel GmbH. Because of automation, there was no waiting time
of derivatised samples on the autosamplers, thus reducing degradation of unstable metabolites.
Moreover, this method allowed us to overlap samples and improved throughputs. We compared
data obtained from both manual and automated TMS methods performed on three different matrices,
including standard mix, wine, and plasma samples. The automated TMS method showed better
reproducibility and higher peak intensity for most of the identified metabolites than the manual
derivatisation method. We also validated the automated method using 114 quality control plasma
samples. Additionally, we showed that this online method was highly reproducible for most of the
metabolites detected and identified (RSD < 20) and specifically achieved excellent results for sugars,
sugar alcohols, and some organic acids. To the very best of our knowledge, this is the first time that
the automated TMS method has been applied to analyse a large number of complex plasma samples.
Furthermore, we found that this method was highly applicable for routine metabolite profiling
(both targeted and untargeted) in any metabolomics laborator
Patterns and Associated Factors of Caesarean Delivery Intention among Expectant Mothers in China: Implications from the Implementation of China’s New National Two-Child Policy
Objective: This study explores the basic demographic characteristics of expectant mothers in
the context of their intentions regarding mode of delivery, in particular, the preference for caesarean
delivery, and analyzes the social and psychological factors that influence delivery preference. Method:
A cross-sectional survey of pregnant women was conducted during June to August in 2015. This study
adopted a stratified sampling method, and 16 representative hospitals in five provinces of China
were included. Results: 1755 and 590 of expectant mothers in their first and second pregnancies,
respectively, were enrolled in this study. 354 (15.10%) intended to deliver by caesarean section and
585 (24.95%) participants were uncertain prior to delivery. 156 (8.89%) of expectant mothers in their
first pregnancy and 198 (33.56%) expectant mothers in their second pregnancy intended to deliver
by caesarean section. Ordinal logistic regression analysis found that nationality, parity, trimester of
pregnancy, and advanced maternal age were factors associated with intention to deliver by caesarean
(ordered logistic regression/three-level caesarean delivery intention criterion; odds ratios p < 0.05).
Conclusions: 8.89% of first pregnancy expectant mothers and 33.56% of second pregnancy expectant
mothers intended to deliver by caesarean section. Any intervention program to reduce the rate of
Caesarean delivery should focus on the Han population, older pregnant women, and expectant
mothers in their second pregnancy, at an early gestation
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The impact of viral mutations on recognition by SARS-CoV-2 specific T cells
We identify amino acid variants within dominant SARS-CoV-2 T cell epitopes by interrogating global sequence data. Several variants within nucleocapsid and ORF3a epitopes have arisen independently in multiple lineages and result in loss of recognition by epitope-specific T cells assessed by IFN-γ and cytotoxic killing assays. Complete loss of T cell responsiveness was seen due to Q213K in the A∗01:01-restricted CD8+ ORF3a epitope FTSDYYQLY207-215; due to P13L, P13S, and P13T in the B∗27:05-restricted CD8+ nucleocapsid epitope QRNAPRITF9-17; and due to T362I and P365S in the A∗03:01/A∗11:01-restricted CD8+ nucleocapsid epitope KTFPPTEPK361-369. CD8+ T cell lines unable to recognize variant epitopes have diverse T cell receptor repertoires. These data demonstrate the potential for T cell evasion and highlight the need for ongoing surveillance for variants capable of escaping T cell as well as humoral immunity