" Candidatus Mesochlamydia elodeae” (Chlamydiae: Parachlamydiaceae ), a novel chlamydia parasite of free-living amoebae

Vannella sp. isolated from waterweed Elodea sp. was found infected by a chlamydia-like organism. This organism behaves like a parasite, causing the death through burst of its host. Once the vannellae degenerated, the parasite was successfully kept in laboratory within a Saccamoeba sp. isolated from the same waterweed sample, which revealed in fine through electron microscopy to harbor two bacterial endosymbionts: the chlamydial parasite we introduce and another endosymbiont initially and naturally present in the host. Herein, we provide molecular-based identification of both the amoeba host and its two endosymbionts, with special focus on the chlamydia parasite. High sequence similarity values of the 18S rDNA permitted to assign the amoeba to the species Saccamoeba lacustris (Amoebozoa, Tubulinea). The bacterial endosymbiont naturally harbored by the host belonged to Sphingomonas koreensis (Alpha-Proteobacteria). The chlamydial parasite showed a strict specificity for Saccamoeba spp., being unable to infect a variety of other amoebae, including Acanthamoeba, and it was itself infected by a bacteriophage. Sequence similarity values of the 16S rDNA and phylogenetic analysis indicated that this strain is a new member of the family Parachlamydiaceae, for which we propose the name "Candidatus Mesochlamydia elodeae.

Motion artefact detection in structured illumination microscopy for live cell imaging

The reconstruction process of structured illumination microscopy (SIM) creates substantial artefacts if the specimen has moved during the acquisition. This reduces the applicability of SIM for live cell imaging, because these artefacts cannot always be recognized as such in the final image. A movement is not necessarily visible in the raw data, due to the varying excitation patterns and the photon noise. We present a method to detect motion by extracting and comparing two independent 3D wide-field images out of the standard SIM raw data without needing additional images. Their difference reveals moving objects overlaid with noise, which are distinguished by a probability theory-based analysis. Our algorithm tags motion-artefacts in the final high-resolution image for the first time, preventing the end-user from misinterpreting the data. We show and explain different types of artefacts and demonstrate our algorithm on a living cell

Measurement-based Geometrical Characterization of the Vehicle-to-Vulnerable-Road-User Communication Channel

Vehicle-to-vulnerable road user (V2VRU) communications have the ability to provide 360 degrees of awareness to both vehicles and vulnerable road users (VRUs) to prevent accidents. An accurate V2VRU channel model in critical accident scenarios is essential to develop a reliable communications system. Therefore, extensive wideband single-input and single-output (SISO) channel measurement campaigns at 5.2 GHz were carried out in open-field and urban environments. Accident prone scenarios between a vehicle and a cyclist as well as between a vehicle and a pedestrian are considered. In this paper, locations of the scatterers in the propagation environment are estimated. We propose a method to extract specular MPCs from the estimated time variant channel impulse response (CIR) based on the density of neighboring MPCs. The specular MPCs are then tracked using a novel tracking algorithm based on the multipath component distance (MCD) approach. Each path is then related to a physical scatterer in the propagation environment by employing a joint delay-Doppler estimation. According to the results, single and double bounce reflections from buildings and parked vehicles are identified in line-of-sight (LoS) situation. In non-LoS (NLoS) situation, scattering from nearby trees as well as reflections from traffic signs and lampposts beneath the trees canopy are identified

Pilot study: peripheral biomarkers for diagnosing sporadic Parkinson's disease

The need for an early and differential diagnosis of Parkinson's disease (PD) is undoubtedly one of the main quests of the century. An early biomarker would enable therapy to begin sooner and would, hopefully, slow or better prevent progression of the disease. We performed transcript profiling via quantitative RT-PCR in RNA originating from peripheral blood samples. The groups were de novo (n=11) and medicated PD (n=94) subjects and healthy controls (n=34), while for negative control Alzheimer's disease (AD; n=14) subjects were recruited as an additional neurodegenerative disease. The results were retested on a second recruitment consisting 22 medicated PD subjects versus 33 controls and 12 AD. Twelve transcripts were chosen as candidate genes, according to previous postmortem brain profiling. Multiple analyses resulted in four significant genes: proteasome (prosome, macropain) subunit-alpha type-2 (PSMA2; p=0.0002, OR=1.15 95% CI 1.07-1.24), laminin, beta-2 (laminin S) (LAMB2; p=0.0078, OR=2.26 95% CI 1.24-4.14), aldehyde dehydrogenase 1 family-member A1 (ALDH1A1; p=0.016, OR=1.05 95% CI 1.01-1.1), and histone cluster-1 H3e (HIST1H3E; p=0.03, OR=0.975 95% CI 0.953-0.998) differentiating between medicated PD subjects versus controls. Using these four biomarkers for PD diagnosis, we achieved sensitivity and specificity of more than 80%. These biomarkers might be specific for PD diagnosis, since in AD subjects no significant results were observed. In the second validation, three genes (PSMA2, LAMB2 and ALDH1A1) demonstrated high reproducibility. This result supports previous studies of gene expression profiling and may facilitate the development of biomarkers for early diagnosis of P

Left ventricular function at 24 hours, 14 days and 6 months after acute myocardial infarction

To determine the natural history of left ventricular function at rest and during exercise and to assess the impact of this variable on subsequent mortality, 165 patients were studied with radionuclide angiography within 24 hours of acute myocardial infarction. The ejection fraction of the 19 patients who died during the 6 month follow-up was lower than that of the 146 survivals: 41±16% vs 50±13% (P<0.001). Before hospital discharge (14±4 days), 83 patients had a rest and submaximal exercise radionuclide study. The ejection fraction of the 42 patients with anterior infarction was 44±12% and remained unchanged during exercise, while the 41 patients with posterior infarction had a resting value of 54±9% which increased to 57±10% (P<0.001) during exercise. The ejection fraction during exercise increased slightly but significantly in 37/61 patients with single vessel disease, while it did not change in the 24/61 patients with multivessel disease. At a mean of 4±1 months following infarction, 58 patients underwent a symptom-limited exercise radionuclide study. Mean value of resting ejection fraction for the group or anterior-posterior infarction subgroups did not change from initial or predischarge values. The 27 patients with anterior infarction showed no change in ejection fraction during exercise, while the 31 patients with posterior infarction increased their ejection fraction from 53±11% to 57±12% (P<0.001). Thus, ejection fraction measured by radionuclide angiography 24 hours following acute myocardial infarction provides useful prognostic information. Moreover, data collected 14 days and 4 months after infarction indicate that no significant change in ejection fraction occurred at rest or during exercise compared with values at rest for the group as a whole. However, ejection fraction values of patients with posterior infarction or of patients with single vessel disease increased with exercise, indicating that after myocardial infarction the capacity for improvement in myocardial function does exist in those patients who manifest the least extensive ischaemic or necrotic damag

Saharan Mineral Dust Experiments SAMUM-1 and SAMUM-2: What have we learned?

Two comprehensive field campaigns were conducted in 2006 and 2008 in the framework of the Saharan Mineral Dust Experiment (SAMUM) project. The relationship between chemical composition, shape morphology, size distribution and optical effects of the dust particles was investigated. The impact of Saharan dust on radiative transfer and the feedback of radiative effects upon dust emission and aerosol transport were studied. Field observations (ground-based, airborne and remote sensing) and modelling results were compared within a variety of dust closure experiments with a strong focus on vertical profiling. For the first time, multiwavelength Raman/polarization lidars and an airborne high spectral resolution lidar were involved in major dust field campaigns and provided profiles of the volume extinction coefficient of the particles at ambient conditions (for the full dust size distribution), of particle-shape-sensitive optical properties at several wavelengths, and a clear separation of dust and smoke profiles allowing for an estimation of the single-scattering albedo of the biomass-burning aerosol. SAMUM–1 took place in southern Morocco close to the Saharan desert in the summer of 2006, whereas SAMUM–2 was conducted in Cape Verde in the outflow region of desert dust and biomass-burning smoke from western Africa in the winter of 2008. This paper gives an overview of the SAMUM concept, strategy and goals, provides snapshots (highlights) of SAMUM–2 observations and modelling efforts, summarizes main findings of SAMUM–1 and SAMUM–2 and finally presents a list of remaining problems and unsolved questions

Regularity for harmonic maps into certain Pseudo-Riemannian manifolds

In this article, we investigate the regularity for certain elliptic systems without a $L^2$-antisymmetric structure. As applications, we prove some $\epsilon$-regularity theorems for weakly harmonic maps from the unit ball $B= B(m) \subset \mathbb{R}^m$ $(m\geq2)$ into certain pseudo-Riemannian manifolds: standard stationary Lorentzian manifolds, pseudospheres $\mathbb{S}^n_\nu \subset \mathbb{R}^{n+1}_\nu$ $(1\leq\nu \leq n)$ and pseudohyperbolic spaces $\mathbb{H}^n_\nu \subset \mathbb{R}^{n+1}_{\nu+1}$ $(0\leq\nu \leq n-1)$. Consequently, such maps are shown to be H\"{o}lder continuous (and as smooth as the regularity of the targets permits) in dimension $m=2$. In particular, we prove that any weakly harmonic map from a disc into the De-Sitter space $\mathbb{S}^n_1$ or the Anti-de-Sitter space $\mathbb{H}^n_1$ is smooth. Also, we give an alternative proof of the H\"{o}lder continuity of any weakly harmonic map from a disc into the Hyperbolic space $\mathbb{H}^n$ without using the fact that the target is nonpositively curved. Moreover, we extend the notion of generalized (weakly) harmonic maps from a disc into the standard sphere $\mathbb{S}^n$ to the case that the target is $\mathbb{S}^n_\nu$ $(1\leq\nu \leq n)$ or $\mathbb{H}^n_\nu$ $(0\leq\nu \leq n-1)$, and obtain some $\epsilon$-regularity results for such generalized (weakly) harmonic maps.Comment: to appear in J. Math. Pures App

The LHCb trigger and data acquisition system

The LHCb experiment is the most recently approved of the 4 experiments under construction at CERNs LHC accelerator. It is a special purpose experiment designed to precisely measure the CP violation parameters in the B-B system. Triggering poses special problems since the interesting events containing B-mesons are immersed in a large background of inelastic p-p reactions. We therefore decided to implement a 4 level triggering scheme. The LHCb Data Acquisition (DAQ) system will have to cope with an average trigger rate of ~40 kHz, after two levels of hardware triggers, and an average event size of ~100 kB. Thus an event-building network which can sustain an average bandwidth of 4 GB/s is required. A powerful software trigger farm will have to be installed to reduce the rate from the 40 kHz to ~100 Hz of events written to permanent storage. In this paper we outline the general architecture of the Trigger and DAQ system and the readout protocols we plan to implement. First results of simulations of the behavior of the event- building network implementations under the expected traffic patterns are presented. (8 refs)

What is the role of Swiss domestic cats in environmental contamination with Echinococcus multilocularis eggs?

Background The role of the domestic cat as definitive host for Echinococcus multilocularis and thus in environmental contamination with eggs has not yet been entirely resolved. This study aimed to assess the prevalence of E. multilocularis and other gastrointestinal parasites in Swiss domestic cats and to compare the diagnostic sensitivity of different methods for the detection of intestinal taeniid infection. Methods Faecal samples from 146 cats were included in the study. Faecal samples only were available from 55 cats; for the other 91 cats, necropsy was performed in addition to faecal sample testing. All (n = 146) faecal samples were analysed by a combined sedimentation/flotation technique (44% ZnCl2) and by the sodium acetate-acetic acid-formalin (SAF) sedimentation technique; when sufficient material was available (n = 121 samples) the Baermann-Wetzel technique was also used. Additionally, all samples were analysed by two coproantigen (copro)-quantitative PCRs (qPCR): (i) a multiplex qPCR able to detect and differentiate between E. multilocularis, Echinococcus granulosus sensu lato and Taenia spp./other cestodes (CEST-qPCR) and (ii) an E. multilocularis-specific qPCR (EM-qPCR). Finally, the intestines were examined macroscopically and microscopically for parasite stages at necropsy (n = 91) and using an intestinal scraping technique (IST) (n = 64). Results Of the 146 cats examined, 24 (17.1%) were infected by intestinal parasites, namely Hydatigera (syn. Taenia) taeniaeformis (8.9%), Toxocara cati (6.1%), Capillaria sp. (3.4%), hookworms (3.4%), Mesocestoides litteratus (1.4%), Giardia sp. (1.4%), Cystoisospora rivolta (1.4%), Cystoisospora felis (0.7%), Toxoplasma gondii (0.7%), Hammondia hammondi (0.7%) and Strongyloides sp. (0.7%). Necropsy and the IST revealed adult H. taeniaeformis in 12 animals, of which eight faecal samples were positive by the CEST-qPCR (sensitivity = 67%) and six samples by the sedimentation/flotation technique (sensitivity = 50%). No E. multilocularis infection was detected in the sampled cats. Using Bayesian latent class analysis, the mean posterior prevalence probability was 0.0% (95% confidence interval 0–0.83%) for E. multilocularis. Conclusions There was no evidence of E. multilocularis infection among the 146 cats examined, suggesting that the prevalence of this parasite is low (< 1%) in the Swiss domestic cat population. Nonetheless, some of the sampled cats were infected by parasites that have rodents as intermediate hosts, demonstrating successful predation by these cats, and some were infected with zoonotic parasites. Cats therefore should not be disregarded as potential hosts for E. multilocularis and other zoonotic parasites