1,149 research outputs found
The Role of Multiple Electron Capture in the X-Ray Emission Process Following Charge Exchange Collisions with Neutral Targets
In this work we theoretically study photonic spectra that follow charge exchange processes between highly charged ions and neutral argon and CO targets. The range of collision energies studied is 5 eV/amu-10 keV/amu, covering typical EBIT-traps and Solar Wind energies. Our studies are based on multiple electrons schemes within the classical trajectory Monte Carlo method. Electrons are sorted with the sequential binding energies for the target under consideration. The role played by the multiple electron capture process for the different collision systems under consideration is explicitly analyzed and its contribution separated as arising from double radiative decay and autoionizing multiple capture. Present studies are stimulated by the upcoming launch of the Astro-H mission in 2015, which will provide high resolution spectra in the 0.3 keV-12keV band
X-Ray Emission Produced in Charge-Exchange Collisions between Highly Charged Ions and Argon: Role of the Multiple Electron Capture
In this work we use the classical trajectory Monte Carlo method within an eight-electron scheme to theoretically study photonic spectra that follow charge-exchange processes between highly charged ions of charge states 10+, 17+, 18+, and 36+ with neutral argon. The energy range considered is 18 eV/amu to 4 keV/amu, covering typical electron beam ion traps and solar wind energies. The role played by multiple electron capture processes for the different collision systems under consideration is explicitly analyzed and its contribution separated as arising from radiative decay and autoionizing multiple capture. For the present collision systems we find that multiple electron capture is responsible for 50%-60% of the resulting x-ray spectra. The present results are of direct relevance to the astrophysical program
Reply to Comment on \u27Classical Description of H(1s) and H* (n=2) for Cross-Section Calculations Relevant to Charge-Exchange Diagnostics\u27
In reply to the Comment of Jorge et al. [Phys. Rev. A 93, 066701 (2016)], we agree and reconfirm that the alternative classical trajectory Monte Carlo method (called hydrogenic-Z-CTMC) radial distributions for H*(n = 2) we recently published are not stable in time. However, we show that such lack of stability which is more noticeable for H(2s) than for H(2p) is due to the initialization procedure employed and not to the hydrogenic-Z-CTMC method itself. A new set of completely stable hydrogenic-Z-CTMC calculations for H*(n = 2) is introduced and found in very good agreement with standard microcanonical results reinforcing our previous findings. A second criticism of Jorge et al. concerning the number of components in hydrogenic-Z-CTMC with n \u3e 1 for H(1s) is shown not to have a significant impact on relative (n,l) populations in the final state
Effectiveness of the spot-on combination of moxidectin and imidacloprid (Advocate®) in the treatment of ocular thelaziosis by Thelazia callipaeda in naturally infected cats
Background: The present study evaluated the therapeutic effectiveness of moxidectin 1.0% (w/v) and imidacloprid 10% (w/v) (Advocate® spot-on solution for cats, Bayer Animal Health) against natural infections with the eyeworm Thelazia callipaeda in cats. This study was conducted as a GCP, negative-controlled, blinded and randomised field study in privately owned cats living in an area in southern Italy where T. callipaeda is enzootic. Methods: The study was carried out in 30 cats (19 females and 11 males, aged from 8 months to 5 years, weighing 1.2-5.2 kg) of different breeds, naturally infected by T. callipaeda. At study inclusion (Day 0), animals were physically examined and the infection level was assessed by examination of both eyes for clinical score and live adult T. callipaeda count. Each cat was weighed and randomly assigned to one of the treatment groups (G1: Advocate, G2: untreated control). Clinical assessments and T. callipaeda adult counts were performed on Day 14. At the study completion visit on Day 28, clinical assessments and counts of T. callipaeda adults and larvae were performed. All cats were daily observed by their owners and general health conditions were recorded during the entire period of the study. Results: The primary effectiveness variable was the percentage of animals in G1 group (Advocate) showing a complete elimination (parasitological cure) of adult eye worms at Day 14 and Day 28. The effectiveness of the treatment in the G1 group was 93.3 and 100% at Day 14 and Day 28, respectively, when compared to group G2. Total worm count reduction from both eyes for Advocate was 96.3% on Day 14 and 100% on Day 28. Clinical data were confirmed by the examination of conjunctival pouch flushing. An overall reduction in the number of cats with lacrimation and conjunctivitis was observed following treatment despite the fact that in a few cats treated with Advocate clinical signs persisted due to the chronic nature of the disease. Conclusions: Based on the results of the present trial, a single dose of Advocate was found to be safe and highly effective in the treatment of natural T. callipaeda infection in cats
Phospholipase activity of yeasts from wild birds and possible implications for human disease
Over the last decades, reports on yeast infections in humans have increased
especially with respect to immunocompromised individuals. Phospholipases
are enzymes which may be associated with pathogenic processes caused by
opportunistic yeasts. Phospholipase activity (ph.a.) was investigated in 163
isolates of 13 species of yeasts. A total of 133 isolates were obtained through
the screening of a total of 768 cloacae of wild birds (Group I: 182 birds of
prey; Group II: 165 passeriformes and Group III: 421 other wild migratory
birds), while 30 isolates were recovered from the droppings of birds housed in 32
distinct aviaries (Group IV). Phospholipase production was evaluated and
quantified at 2 and 5 day pre-incubation (Pr.t) and incubation times (I.t).
Isolates from cloacae (48.1%) and excreta (73.3%) produced ph.a. with the
highest values registered after 5 days of I.t. Candida albicans, C. tropicalis, C.
glabrata, C. lusitaniae, C. pelliculosa, Cryptococcus albidus, C. laurentii, Trichosporon
beigelii, and Saccharomyces cerevisiae displayed the highest ph.a. after
2 days of Pr.t while Candida famata, C. guilliermondii and Cryptococcus
neoformans after 5 days of Pr.t. Ph.a. was never found in Rhodotorula rubra
isolates recovered from the cloacae of wild birds. Isolates (73.3%) from bird
droppings showed a higher ph.a. than those from cloacae thus indicating that
wild birds not only act as carriers but may also spread phospholipase-producing
yeasts in the environment
Reptile vector-borne diseases of zoonotic concern
Reptile vector-borne diseases (RVBDs) of zoonotic concern are caused by bacteria, protozoa and viruses transmitted by arthropod vectors, which belong to the subclass Acarina (mites and ticks) and the order Diptera (mosquitoes, sand flies and tsetse flies). The phyletic age of reptiles since their origin in the late Carboniferous, has favored vectors and pathogens to co-evolve through millions of years, bridging to the present host-vector-pathogen interactions. The origin of vector-borne diseases is dated to the early cretaceous with Trypanosomatidae species in extinct sand flies, ancestral of modern protozoan hemoparasites of zoonotic concern (e.g., Leishmania and Trypanosoma) associated to reptiles. Bacterial RVBDs are represented by microorganisms also affecting mammals of the genera Aeromonas, Anaplasma, Borrelia, Coxiella, Ehrlichia and Rickettsia, most of them having reptilian clades. Finally, reptiles may play an important role as reservoirs of arborivuses, given the low host specificity of anthropophilic mosquitoes and sand flies. In this review, vector-borne pathogens of zoonotic concern from reptiles are discussed, as well as the interactions between reptiles, arthropod vectors and the zoonotic pathogens they may transmit
Hyperplastic cholangitis in a naturally Toxoplasma gondii-infected cat.
Toxoplasma gondii can cause in cats a multisystemic disease involving the liver, lungs, central nervous system and other organs. The liver generally shows multifocal necrotizing hepatitis with possible panlobular extension, with histological evidence of free tachyzoites and/or cysts containing bradyzoites within necrotic foci. Very rarely, toxoplasmosis is expressed by cholangitis, the latter being much more frequently caused in cats by bacteria of intestinal origin.
We report here a case of cholangitis/cholangiohepatitis in a young cat, where cytology of the liver showed multiple maturational stages of protozoa in the cytoplasm of cells of the bile ducts. On the basis of the cytological, histological, ultrastructural and molecular details, the microorganisms were identified as belonging to the species Toxoplasma gondii
Mixed trichuroid infestation in a dog from Italy
Background: Capillaria aerophila, Capillaria boehmi and Trichuris vulpis are trichuroid nematodes affecting wild and companion animals all over the World. The canine intestinal whipworm, T. vulpis, is the most common and wellknown in veterinary practice, whereas the respiratory C. aerophila and C. boehmi have been rarely reported in pets as a likely consequence of overlapping morphometric and morphological features of the eggs, which impair a correct etiological diagnosis. Findings: In December 2011, a mixed infestation by T. vulpis, C. aerophila and C. boehmi was diagnosed in an asymptomatic dog living in central Italy. Morphometric and morphological findings and pictures of the eggs found at the copromicroscopic analysis are herein reported. Conclusions: The present work demonstrates that when trichuroid eggs are found in a faecal sample from a dog, a careful morphological and morphometric analysis of individual parasite elements is mandatory. Key diagnostic features (i.e., size, wall surface pattern and aspects of plugs) should be carefully examined when eggs with overlapping shape and appearance are detected. In conclusion, given the importance in clinical practice of canine trichuroids and the zoonotic potential of C. aerophila, these nematodes should be included into the differential diagnosis of intestinal and respiratory parasitoses of dogs by a thorough microscopic analysis of all trichuroid ova present in microscopic fields
Role of the Recoil Ion in Single-Electron Capture and Single-Ionization Processes for Collisions of Protons with He and Ar Atoms
In this work the single-electron capture and single-ionization processes are studied for proton collisions with He and Ar atoms at impact energies in the range 25–100 keV. Classical trajectory Monte Carlo simulations are benchmarked against experimental data obtained at the reaction microscope in Bariloche, Argentina, which employs the cold target recoil-ion momentum spectroscopy technique. Special emphasis is placed on describing the momentum transfer to the recoil ion for these collision systems
Triply Differential Single Ionization of Argon: Charge Effects for Positron and Electron Impact
Triply differential single ionization of Ar by 200 eV positron and electron impact is measured and calculated. For an unequivocal test of kinematic differences, fully differential ejected electron angular distributions are measured using the same experimental apparatus and conditions for both positron and electron impact. The binary/recoil intensity ratios are shown to significantly differ for the two projectiles. These data are used to test theoretical calculations
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