Compression of sub-relativistic space-charge-dominated electron bunches for single-shot femtosecond electron diffraction

We demonstrate compression of 95 keV, space-charge-dominated electron bunches to sub-100 fs durations. These bunches have sufficient charge (200 fC) and are of sufficient quality to capture a diffraction pattern with a single shot, which we demonstrate by a diffraction experiment on a polycrystalline gold foil. Compression is realized by means of velocity bunching as a result of a velocity chirp, induced by the oscillatory longitudinal electric field of a 3 GHz radio-frequency cavity. The arrival time jitter is measured to be 80 fs

Investigation of amphibian mortality events in wildlife reveals an on-going ranavirus epidemic in the North of the Netherlands

In the four years following the first detection of ranavirus (genus Ranavirus, family Iridoviridae) infection in Dutch wildlife in 2010, amphibian mortality events were investigated nationwide to detect, characterize and map ranaviruses in amphibians over time, and to establish the affected host species and the clinico-pathological presentation of the disease in these hosts. The ultimate goal was to obtain more insight into ranavirus disease emergence and ecological risk. In total 155 dead amphibians from 52 sites were submitted between 2011 and 2014, and examined using histopathology, immunohistochemistry, virus isolation and molecular genetic characterization. Ranavirus-associated amphibian mortality events occurred at 18 sites (35%), initially only in proximity of the 2010 index site. Specimens belonging to approximately half of the native amphibian species were infected, including the threatened Pelobates fuscus (spadefoot toad). Clustered massive outbreaks involving dead adult specimens and ranavirus genomic identity indicated that one common midwife toad virus (CMTV)-like ranavirus strain is emerging in provinces in the north of the Netherlands. Modelling based on the spatiotemporal pattern of spread showed a high probability that this emerging virus will continue to be detected at new sites (the discrete reproductive power of this outbreak is 0.35). Phylogenetically distinct CMTV-like ranaviruses were found in the south of the Netherlands more recently. In addition to showing that CMTV-like ranaviruses threaten wild amphibian populations not only in Spain but also in the Netherlands, the current spread and risk of establishment reiterate that understanding the underlying causes of CMTV-like ranavirus emergence requires international attention

No detection of chytrid in first systematic screening of Bombina variegata pachypus (Anura: Bombinatoridae) in Liguria, northern Italy

The Apennine Yellow-bellied toad Bombina variegata pachypus, a small anuran endemic to peninsular Italy, has been declining throughout its range over the last 30 years. Although mortality by chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis, was first reported for the species in 2004, its role in the decline has not yet been assessed. Between 2011 and 2012 we sampled eight populations of B. v. pachypus in Liguria, northern Italy, swabbing 86 and 143 individuals respectively, corresponding to between 24 and 80% of the estimated individuals within each population. We did not detect chytrid in any the samples collected. For the three largest populations in the region, we can rule out infections of prevalence greater than 10% with at least 98% confidence. Research at a larger scale is urgently needed to clarify the role of B. dendrobatidis in the decline of this and other amphibians in Italy

A systematic review and meta-analysis on Staphylococcus aureus carriage in psoriasis, acne and rosacea

textabstractStaphylococcus aureus might amplify symptoms in chronic inflammatory skin diseases. This study evaluates skin and mucosal colonization with S. aureus in patients with psoriasis, acne and rosacea. A systematic literature search was conducted. Both odds ratios (OR) for colonization in patients versus controls and the prevalence of colonization in patients are reported. Fifteen articles about psoriasis and 13 about acne (12 having a control group) were included. No study in rosacea met our inclusion criteria. For psoriasis, one study out of three controlled studies showed increased skin colonization (OR 18.86; 95 % confidence interval [CI] 2.20–161.99). Three out of the five studies that reported on nasal colonization showed significant ORs varying from 1.73 (95 % CI 1.16–2.58) to 14.64 (95 % CI 2.82–75.95). For acne one of the three studies that evaluated skin colonization reported a significant OR of 4.16 (95 % CI 1.74–9.94). A relation between nasal colonization and acne was not found. Limitations in study design and low sample sizes should be taken into consideration when interpreting the results. Colonisation with S. aureus seems to be increased in patients with psoriasis. This bacterial species, known for its potential to induce long-lasting inflammation, might be involved in psoriasis pathogenesis. Information on acne is limited. Prospective controlled studies should further investigate the role of S. aureus in chronic inflammatory skin diseases

Distribution and morphological characterization of the endemic Italian salamanders Salamandrina perspicillata (Savi, 1821) and S. terdigitata (Bonnaterre, 1789) (Caudata: Salamandridae)

The Italian endemic genus Salamandrina was recently determined to be polytypic since two species, Salamandrina perspicillata and S. terdigitata, were recognized using both mitochondrial and nuclear genetic markers. However, data on their range is very scanty and no morphological traits are available to distinguish between these two taxa. A thorough field survey was carried out to detect and to sample new sites in areas in which Salamandrina remained unrecorded and to sample populations expected to occur in the documented range. Specimens were analyzed for variation of three mitochondrial DNA partial sequences of 12S and 16S ribosomal RNAs and cytochrome b genes. Attribution of individuals to either of the two species was therefore made on the basis of their haplotypes. Here we provide relevant information on the distribution of the two species, which were also found in areas where Salamandrina had previously been unrecorded, i.e. in the eastern Basilicata, in the region of Apulia and within the wide area which separated the two species. In the latter zone, a small area of sympatry between the two species was found. Furthermore, we analyzed the dorsal coloration pattern and size-related characters of the two species using Classification and Regression Tree analysis (CART), the results of which provided the first account of the morphological differences between Salamandrina perspicillata and S. terdigitata. The southern species, S. terdigitata, is smaller in size than S. perspicillata and differs in its coloration, mainly due to the red color on the dorsal surface of its tail. © 2009 Unione Zoologica Italiana

Widespread occurrence of an emerging fungal pathogen in heavily traded Chinese urodelan species

Understanding introduction routes for wildlife pathogens is vital for the development of threat abatement plans. The chytrid fungus Batrachochytrium salamandrivorans (Bsal) has recently emerged in Europe, where it is considered to be a serious threat for urodelan conservation. If the highly diverse Chinese urodelans were to constitute a Bsal reservoir, then the significant international trade in these species may vector Bsal into naïve urodelan communities. Here, we analyzed a total of 1,143 samples, representing 36 Chinese salamander species from 51 localities across southern China for the presence of Bsal. We found Bsal was present across a wide taxonomic, geographical, and environmental range. In particular, Bsal DNA was detected in 33 samples from the genera Cynops, Pachytriton, Paramesotriton, Tylototriton, and Andrias, including the heavily traded species Paramesotriton hongkongensis and Cynops orientalis. The true Bsal prevalence across our data set was estimated between 2% and 4%, with a maximum of 50% in a population of P. hongkongensis. Even at this overall relatively low Bsal prevalence, the exportation of millions of animals renders Bsal introduction in naïve, importing countries a near certainty, which calls for the urgent implementation of proper biosecurity in the international wildlife trade

An avirulent Brachyspira hyodysenteriae strain elicits intestinal IgA and slows down spread of swine dysentery

Swine dysentery caused by Brachyspira hyodysenteriae, results in substantial economic losses in swine producing countries worldwide. Although a number of different vaccine approaches have been explored with regard to this disease, they show limitations and none of them have reached the market. We here determine the vaccine potential of a weakly haemolytic B. hyodysenteriae strain. The virulence of this strain was assessed in experimental infection trials and its protection against swine dysentery was quantified in a vaccination-challenge experiment using a seeder infection model. Systemic IgG production and local IgA production were monitored in serum and faeces respectively. Across all trials, pigs that were colonized by virulent, strongly haemolytic B. hyodysenteriae strains consistently developed swine dysentery, in contrast to none of the pigs colonized by the weakly haemolytic B. hyodysenteriae vaccine strain. In the seeder vaccination trial nearly all immunised animals developed swine dysentery on subsequent challenge with a virulent strain, but the speed of spread of swine dysentery and faecal score were significantly reduced in animals immunised with the weakly haemolytic strain compared to sham-immunised animals. The IgA response of immunised animals upon challenge with a virulent B. hyodysenteriae strain significantly correlated to a later onset of disease. The correlation between local IgA production and protection induced by a weakly haemolytic B. hyodysenteriae strain provides leads for future vaccine development against swine dysentery

Recent Asian origin of chytrid fungi causing global amphibian declines

Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of the most devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide

Congenital Melanocytic Naevi

Congenital melanocytic naevi (CMN) are birthmarks that can cover large areas of the body. CMN can significantly impact individuals' lives due to perceived stigma, the risk for melanoma development and neurological complications. To treat and prevent these complications, adequate research and guidelines are needed. In this review, we present a summary of the Dutch multidisciplinary guideline and the lessons learned from the implementation and information developed additionally in collaboration with the patient association. We also introduce the core outcomes of the OCOMEN project to standardize outcomes for both research and care of CMN. The next step is the development of the instruments internationally.</p