GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands

GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board

Telomeric DNA in Chironomus, a naturally telomerase-free system

Telomeres are specialized complexes of DNA and associated proteins that protect the ends of eukaryotic chromosomes. Although most organisms have short repeated DNA sequences at their telomeres, which are specified and maintained by the enzyme telomerase, there are a few exceptions. Dipteran insects, including the genus Chironomus (non-biting midges), lack telomerase and have atypical terminal sequences. Chironomids have four chromosomes – three metacentric and one telocentric. In C. pallidivittatus, long (340 bp) and complex telomere-specific repeats terminate the seven nontelocentric chromosome ends and a similar situation probably occurs in related species. Although this DNA evolves rapidly, it is shown here that some sequence features are conserved among three analyzed Chironomus species, including C. pallidivittatus. Another one of these species (C. tentans) was found to lack the long single-stranded overhangs characteristic of canonical telomeres (those maintained by telomerase). The eighth, telocentric chromosome end, on the other hand, contains 155 bp centromere-specific repeats. In this study, it is shown that these 155 bp units extend to the very end of the chromosome. Consequently, it appears that one and the same cell can use different terminating repeats at different chromosome ends. The telocentric end is also unique in that it was found to contain an active gene, probably derived from a transposon, close to the telocentric repeat array. This gene could be involved in maintenance of the adjoining telomere and requires further investigation. Previous studies have shown that gene conversion is one factor in the maintenance of telomeric DNA at nontelocentric chromosome ends. The possibility of RNA-based telomere elongation, which was suggested by earlier immunolocalization of reverse transcriptase to telomeres, was addressed here. A previously identified RNase-sensitive fraction, hybridizing to telomeric repeats was found to be a double-stranded extrachromosomal component containing both DNA and RNA and to be unique to telomeres. However, additional research is required in order to evaluate the possible role of this material in telomere maintenance

Chromosome ends in Chironomus tentans do not have long single-stranded overhangs characterizing canonical telomeres.

Single-stranded overhangs of the G-rich strand belong to the conserved features of telomeres composed of short telomeric repeats. These structures are thought to be essential for the maintenance of proper telomeric structure and function and the mechanism of their generation is telomerase-independent. We have examined the presence of single-stranded overhangs in Chironomus tentans, a dipteran insect lacking canonical telomeres that uses 350-bp repeats to terminate its chromosomes. Using a non-denaturing in-gel hybridization technique, we found that C. tentans telomeres are unlikely to have single-stranded overhangs longer than 30 nt found in most other higher eukaryotes. These differences might reflect special capping mechanisms for telomeres terminated with long complex repeats

Extrachromosomal RNA-DNA complex containing long telomeric repeats in chironomids.

We have analysed an extracted RNase sensitive fraction containing telomeric repeat sequences in the telomerase negative dipteran Chironomus tentans. It shows a slow and well-defined electophoretic migration corresponding to > 20 kb and is sensitive not only to RNase, but also to DNase. It hybridizes to both strands of the telomeric repeat with about equal intensities. DNA is probably the dominant component since the fraction is only slightly heavier than genomic DNA in isopycnic gradients but considerably lighter than RNA. It can, nevertheless, be shown to incorporate tritiated uridine. The material might represent another example of extrachromosomal telomeric repeats in telomerase negative cells

Telomere terminating with centromere-specific repeats is closely associated with a transposon derived gene in Chironomus pallidivittatus

We provide evidence that centromere-specific 155 bp DNA repeats terminate one pair of telomeres at the telocentric, left end of the short fourth chromosome in Chironomus pallidivittatus. Earlier evidence indicated that all other telomeres are terminated by 340 bp telomere-specific repeats. DNA that borders the 155 bp repeat contains a transcriptionally active 396 codon open reading frame (ORF) a few kilobases away from the repeat array. The conceptual product of the ORF has regions with similarities to transposase, DNA binding and endonuclease motifs and is likely to have an evolutionary origin in a transposon. It is flanked, within degenerate inverted repeats, by a modified form of an element. Cp80, that has previously been found to insert only into 155 bp repeats and that contains a putative CENP-B box and a region that is prone to recombine. The ORF may therefore have a functional relation to the centromeric region

Fixed-Combination Calcipotriene Plus Betamethasone Dipropionate Aerosol Foam Is Well Tolerated in Patients with Psoriasis Vulgaris: Pooled Data from Three Randomized Controlled Studies

The authors performed a pooled analysis of three randomized, 4-week, phase II/III studies in adult patients with mild to severe psoriasis and assessed the safety/tolerability of aerosol foam fixed-combination calcipotriene 0.005% (Cal) plus betamethasone dipropionate 0.064% (BD) versus different comparators. Overall, 1104 patients were randomized to Cal/BD aerosol foam (n=564), Cal aerosol foam (n=101), BD aerosol foam (n=101), aerosol foam vehicle (n=152), Cal/BD ointment (n=135), or ointment vehicle (n=51). A total of 543 Cal/BD patients in the aerosol foam group (96.3%) completed the studies, with only two patients (0.4%) withdrawing as a result of adverse events (AEs). Ninety-five AEs were reported in 78 patients (13.8%) receiving Cal/BD aerosol foam; similar event rates were observed in other groups. The most common AEs with Cal/BD aerosol foam were nasopharyngitis (n=6, 1.1%) and application-site pain (n=4, 0.7%); most AEs were mild (n=71/95; 74.7%). Adverse drug reactions (ADRs) experienced by two or more patients receiving Cal/BD aerosol foam were application-site pain (n=4; 0.7%) and application-site pruritus (n=2; 0.4%). There were no clinically relevant changes in calcium homeostasis. Cal/BD aerosol foam has a positive benefit-risk profile for the treatment of psoriasis vulgaris; the superior efficacy versus Cal/BD ointment and the individual active ingredients is not associated with poorer tolerability

Standardized computer-based organized reporting of EEG : SCORE - Second version

Standardized terminology for computer-based assessment and reporting of EEG has been previously developed in Europe. The International Federation of Clinical Neurophysiology established a taskforce in 2013 to develop this further, and to reach international consensus. This work resulted in the second, revised version of SCORE (Standardized Computer-based Organized Reporting of EEG), which is presented in this paper. The revised terminology was implemented in a software package (SCORE EEG), which was tested in clinical practice on 12,160 EEG recordings. Standardized terms implemented in SCORE are used to report the features of clinical relevance, extracted while assessing the EEGs. Selection of the terms is context sensitive: initial choices determine the subsequently presented sets of additional choices. This process automatically generates a report and feeds these features into a database. In the end, the diagnostic significance is scored, using a standardized list of terms. SCORE has specific modules for scoring seizures (including seizure semiology and ictal EEG patterns), neonatal recordings (including features specific for this age group), and for Critical Care EEG Terminology. SCORE is a useful clinical tool, with potential impact on clinical care, quality assurance, data-sharing, research and education

Management practices for postdural puncture headache in obstetrics: a prospective, international, cohort study

© 2020 British Journal of AnaesthesiaBackground: Accidental dural puncture is an uncommon complication of epidural analgesia and can cause postdural puncture headache (PDPH). We aimed to describe management practices and outcomes after PDPH treated by epidural blood patch (EBP) or no EBP. Methods: Following ethics committee approval, patients who developed PDPH after accidental dural puncture were recruited from participating countries and divided into two groups, those receiving EBP or no EBP. Data registered included patient and procedure characteristics, headache symptoms and intensity, management practices, and complications. Follow-up was at 3 months. Results: A total of 1001 patients from 24 countries were included, of which 647 (64.6%) received an EBP and 354 (35.4%) did not receive an EBP (no-EBP). Higher initial headache intensity was associated with greater use of EBP, odds ratio 1.29 (95% confidence interval 1.19–1.41) per pain intensity unit increase. Headache intensity declined sharply at 4 h after EBP and 127 (19.3%) patients received a second EBP. On average, no or mild headache (numeric rating score≤3) was observed 7 days after diagnosis. Intracranial bleeding was diagnosed in three patients (0.46%), and backache, headache, and analgesic use were more common at 3 months in the EBP group. Conclusions: Management practices vary between countries, but EBP was more often used in patients with greater initial headache intensity. EBP reduced headache intensity quickly, but about 20% of patients needed a second EBP. After 7 days, most patients had no or mild headache. Backache, headache, and analgesic use were more common at 3 months in patients receiving an EBP