Improved retrieval of complex supercontinuum pulses from XFROG traces using a ptychographic algorithm.

We demonstrate that time-domain ptychography, a recently introduced iterative ultrafast pulse retrieval algorithm, has properties well suited for the reconstruction of complex light pulses with large time-bandwidth products from a cross-correlation frequency-resolved optical gating (XFROG) measurement. It achieves temporal resolution on the scale of a single optical cycle using long probe pulses and low sampling rates. In comparison to existing algorithms, ptychography minimizes the data to be recorded and processed, and significantly reduces the computational time of the reconstruction. Experimentally, we measure the temporal waveform of an octave-spanning, 3.5 ps long, supercontinuum pulse generated in photonic crystal fiber, resolving features as short as 5.7 fs with sub-fs resolution and 30 dB dynamic range using 100 fs probe pulses and similarly large delay steps.

All-optical implementation of a time-domain ptychographic pulse reconstruction setup.

An all-optical implementation of pulse reconstruction using time-domain ptychography has been demonstrated showing excellent results. The implementation was easy to set up and eliminated a number of drawbacks found in other second-order techniques, such as the beam splitter modifying the pulse under consideration, the time ambiguity, or the strict correspondence between time delay increment and temporal resolution. Ptychography generally offers superior performance compared to algorithms based on general projections, requires considerably less computational effort, and is much less susceptible to noise.

All-optical implementation of a time-domain ptychographic pulse reconstruction setup: publisher's note.

This note reports author corrections that were omitted from Appl. Opt.55, 5008 (2016) 10.1364/AO.55.005008 in error during production. The article was corrected online 23 June 2016.

From Stable to Lab-Investigating Key Factors for Sudden Deaths Caused by Streptococcus suis.

Swine stocks are endemically infected with the major porcine pathogen Streptococcus (S.) suis. The factors governing the transition from colonizing S. suis residing in the tonsils and the exacerbation of disease have not yet been elucidated. We analyzed the sudden death of fattening pigs kept under extensive husbandry conditions in a zoo. The animals died suddenly of septic shock and showed disseminated intravascular coagulopathy. Genotypic and phenotypic characterizations of the isolated S. suis strains, a tonsillar isolate and an invasive cps type 2 strain, were conducted. Isolated S. suis from dead pigs belonged to cps type 2 strain ST28, whereas one tonsillar S. suis isolate harvested from a healthy animal belonged to ST1173. Neither S. suis growth, induction of neutrophil extracellular traps, nor survival in blood could explain the sudden deaths. Reconstituted blood assays with serum samples from pigs of different age groups from the zoo stock suggested varying protection of individuals against pathogenic cps type 2 strains especially in younger pigs. These findings highlight the benefit of further characterization of the causative strains in each case by sequence typing before autologous vaccine candidate selection.

Experimental ASD closure using autologous cell-seeded interventional closure devices.

OBJECTIVE: Atrial septal defect (ASD) occluders are permanent implants in paediatric cardiology which serve as mechanical shields until complete overgrowth and incorporation of the occluding device by autologous tissue has occurred. Thereafter, the foreign body material making up the device is dispensable and bears potential long-term adverse effects. Rapid, firm and complete incorporation into the atrial septal wall should be a prerequisite for biodegradable devices. In this study, the feasibility of using autologous cell-seeded devices was investigated by (a) testing the influence of a collagen coating on cellular stress resistance in vitro and (b) comparing the short-term effects between cell-seeded, collagen-coated and acellular ASD occluders in vivo. METHODS: Native and collagen-coated Dacon fabrics and Starflex-devices were pre-seeded with autologous fibroblasts (skin biopsy) and evaluated using various mechanical stress tests. In a sheep model interventionally created ASDs were closed using either autologous pre-seeded or conventional (acellular) Starflex-devices. RESULTS: ASD closure devices were successfully pre-seeded with autologous cells. The incubation period needed, the cellular density achieved and the mechanical stability of the cytolayer after mechanical stressing (implantation) were improved by applying a collagen matrix on the fabric. Compared to the thin layer of ingrown tissue seen on conventional occluders after 30 days in vivo, a thicker layer of organising, newly formed granulation tissue on pre-seeded collagen-coated devices embedded not only the Dacron fabric, but also completely covered the spring arms of the device underneath a layer of neo-endothelium. CONCLUSION: Autologous cell pre-seeding of interventional closure devices is feasible since the cells survive the mechanical stress encountered during implantation. Rapid, firm and complete ingrowth of occluder devices into a thicker layer of young fibrous granulation tissue can be achieved, but an increased thrombogenicity currently limits the in vivo application.

Demonstration of Mycoplasma bovis by immunohistochemistry and in situ hybridization in an aborted bovine fetus and neonatal calf.

Mycoplasmas are host-specific commensals on mucous membranes of the genital tract, but infection and clinical disease by Mycoplasma bovis in the genital tract of cattle is not well described. In the current study, 1 aborted bovine fetus and 1 neonatal calf were examined macroscopically and histologically. For the detection of M. bovis, bacterial isolation, immunohistochemistry (IHC), and in situ hybridization (ISH) were performed. For further characterization of the inflammatory infiltrates, IHC was performed using antibodies to cluster of differentiation (CD)3, CD79a, lysozyme, L1, S-100A8, S-100A9, and von Willebrand factor VIII. Gross examination revealed a lobular consolidation of the lung. Histologically, the lungs of both animals showed an interstitial pneumonia associated with suppurative bronchopneumonia, intraalveolar multinucleated giant cells, and lymphocytic aggregates. The expression of L1, S-100A8, and S-100A9 in multinucleated giant cells supports a histiocytic origin. Mycoplasma bovis antigen was detected by IHC in brain, lung, liver, and placenta of the fetus, and M. bovis DNA was detected by ISH in various organs of the fetus, including lung and placenta and within the lung of the calf.

Spontaneous degenerative polioencephalomyelopathy in feeder pigs--a new motor neuron disease?

A central nervous disorder occurred spontaneously in a herd of feeder pigs characterized by muscle fasciculations, convulsions, squealing, and acute death in numerous animals. Histopathology revealed a degenerative poliomyeloencephalopathy of brain stem and spinal cord consisting of neuronal hypertrophy, chromatolysis, neuronophagia, and satellitosis associated with Wallerian degeneration of ventral rootlets and neurogenic muscle atrophy of limb musculature. The sudden onset of clinical signs and the pattern of morphological findings were suggestive of intoxication. Though parathion was found in two animals, serum acetylcholine esterase activity and morphological findings were not compatible with an organophosphate poisoning. A hereditary disorder was excluded by genetic analysis. Summarized findings in the present cases are reminiscent of changes observed in ruminants suffering from patulin poisoning, a neuromycotoxicosis caused by Aspergillus clavatus. However, toxicological and microbiological investigations failed to identify the cause of this unusual and so far not described disease in pigs. Morphologically, lesion distribution and alterations of motor neurons resemble changes observed in equine motor neuron disease, spinal muscular atrophy of certain canine breeds, and amyotrophic lateral sclerosis (Lou Gehrig's disease) in man. Therefore, the term spontaneous porcine motor neuron disease (SPMND) is proposed for this new and unique entitiy.