Stray dogs as indicators of Toxoplasma gondii distributed in the environment: the first report across an urban-rural gradient in China

<p>Abstract</p> <p>Background</p> <p>Toxoplasmosis is an important parasitic zoonosis caused by the protozoan <it>Toxoplasma gondii </it>that is distributed world-wide and infects a variety of hosts. However, the prevalence of <it>T. gondii </it>in the environment (such as soil, water and food) is largely unknown. Due to the technical difficulty in oocyst counting directly, an alternative assay using the serologic status of <it>T. gondii </it>in free-living animals, such as stray or free-living dogs, as an indicator, can be used to evaluate environmental contamination indirectly, as they are exposed to the same risk of infection as humans and other animals.</p> <p>Results</p> <p>In the present study, 231 stray or free-living dogs across an urban-rural gradient were examined to assess the frequency of <it>T. gondii </it>in the environment. Specific antibodies to <it>T. gondii </it>were found in 93 dogs (40.3%) by enzyme-linked immunosorbent assay (ELISA), and no statistically significant differences were observed in seroprevalences of <it>T. gondii </it>between urban dogs (38.7%) and rural dogs (41%) (<it>p </it>> 0.05).</p> <p>Conclusions</p> <p>A high seroprevalence of <it>T. gondii </it>in stray or free-living dogs in the present study indicates that there would be a wide distribution and a constant infection pressure of <it>T. gondii </it>across an urban-rural gradient, and the oocysts of <it>T. gondii </it>in the environment would be an important source of infection for humans and other animals both in urban and rural areas in China.</p

The CDEX-1 1 kg Point-Contact Germanium Detector for Low Mass Dark Matter Searches

The CDEX Collaboration has been established for direct detection of light dark matter particles, using ultra-low energy threshold p-type point-contact germanium detectors, in China JinPing underground Laboratory (CJPL). The first 1 kg point-contact germanium detector with a sub-keV energy threshold has been tested in a passive shielding system located in CJPL. The outputs from both the point-contact p+ electrode and the outside n+ electrode make it possible to scan the lower energy range of less than 1 keV and at the same time to detect the higher energy range up to 3 MeV. The outputs from both p+ and n+ electrode may also provide a more powerful method for signal discrimination for dark matter experiment. Some key parameters, including energy resolution, dead time, decay times of internal X-rays, and system stability, have been tested and measured. The results show that the 1 kg point-contact germanium detector, together with its shielding system and electronics, can run smoothly with good performances. This detector system will be deployed for dark matter search experiments.Comment: 6 pages, 8 figure

Whole-Genome Resequencing of Worldwide Wild and Domestic Sheep Elucidates Genetic Diversity, Introgression, and Agronomically Important Loci

Domestic sheep and their wild relatives harbor substantial genetic variants that can form the backbone of molecular breeding, but their genome landscapes remain understudied. Here, we present a comprehensive genome resource for wild ovine species, landraces and improved breeds of domestic sheep, comprising high-coverage (similar to 16.10x) whole genomes of 810 samples from 7 wild species and 158 diverse domestic populations. We detected, in total, similar to 121.2 million single nucleotide polymorphisms, similar to 61 million of which are novel. Some display significant (P < 0.001) differences in frequency between wild and domestic species, or are private to continent-wide or individual sheep populations. Retained or introgressed wild gene variants in domestic populations have contributed to local adaptation, such as the variation in the HBB associated with plateau adaptation. We identified novel and previously reported targets of selection on morphological and agronomic traits such as stature, horn, tail configuration, and wool fineness. We explored the genetic basis of wool fineness and unveiled a novel mutation (chr25: T7,068,586C) in the 3 '-UTR of IRF2BP2 as plausible causal variant for fleece fiber diameter. We reconstructed prehistorical migrations from the Near Eastern domestication center to South-and-Southeast Asia and found two main waves of migrations across the Eurasian Steppe and the Iranian Plateau in the Early and Late Bronze Ages. Our findings refine our understanding of genome variation as shaped by continental migrations, introgression, adaptation, and selection of sheep

Whole-Genome Resequencing of Worldwide Wild and Domestic Sheep Elucidates Genetic Diversity, Introgression, and Agronomically Important Loci

Domestic sheep and their wild relatives harbor substantial genetic variants that can form the backbone of molecular breeding, but their genome landscapes remain understudied. Here, we present a comprehensive genome resource for wild ovine species, landraces and improved breeds of domestic sheep, comprising high-coverage (∼16.10×) whole genomes of 810 samples from 7 wild species and 158 diverse domestic populations. We detected, in total, ∼121.2 million single nucleotide polymorphisms, ∼61 million of which are novel. Some display significant (P < 0.001) differences in frequency between wild and domestic species, or are private to continent-wide or individual sheep populations. Retained or introgressed wild gene variants in domestic populations have contributed to local adaptation, such as the variation in the HBB associated with plateau adaptation. We identified novel and previously reported targets of selection on morphological and agronomic traits such as stature, horn, tail configuration, and wool fineness. We explored the genetic basis of wool fineness and unveiled a novel mutation (chr25: T7,068,586C) in the 3'-UTR of IRF2BP2 as plausible causal variant for fleece fiber diameter. We reconstructed prehistorical migrations from the Near Eastern domestication center to South-and-Southeast Asia and found two main waves of migrations across the Eurasian Steppe and the Iranian Plateau in the Early and Late Bronze Ages. Our findings refine our understanding of genome variation as shaped by continental migrations, introgression, adaptation, and selection of sheep

Article Design, Synthesis, and Antitumor Activities of Some Novel Substituted 1,2,3-Benzotriazines

molecule

Preparation of raspberry-like polypyrrole composites with applications in catalysis

Raspberry-like composites were prepared by coating the silver/polypyrrole core/shell composites onto the surface of silica spheres via oxidation polymerization of pyrrole monomer with [Ag(NH3)2]+ ions as oxidants. The whole process allowed the absence of stabilizers, which greatly improved the quality of the conducting polymer composites. The morphology of the resulting composites was investigated, which can be described as raspberry-like; also, the structure and composition of the composites were characterized in detail. A possible formation mechanism was proposed. The present synthetic strategy substantially extended the scope of metal/conducting polymer composite synthesis. The raspberry-like composites exhibited excellent catalytic properties in the reduction of methylene blue dye with the reducing agent of sodium borohydride.Peer reviewed: YesNRC publication: N

Development of an Iron-Based Fischer—Tropsch Catalyst with High Attrition Resistance and Stability for Industrial Application

In order to develop an iron-based catalyst with high attrition resistance and stability for Fischer–Tropsch synthesis (FTS), a series of experiments were carried out to investigate the effects of SiO2 and its hydroxyl content and a boron promoter on the attrition resistance and catalytic behavior of spray-dried precipitated Fe/Cu/K/SiO2 catalysts. The catalysts were characterized by means of N2 physisorption, nuclear magnetic resonance (NMR), X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS), H2-thermogravimetric analysis (H2-TGA), temperature-programmed reduction and hydrogenation (TPR and TPH), and scanning and transmission electron microscopy (SEM and TEM). The FTS performance of the catalysts was tested in a slurry-phase continuously stirred tank reactor (CSTR), while the attrition resistance study included a physical test with the standard method and a chemical attrition test under simulated reaction conditions. The results indicated that the increase in SiO2 content enhances catalysts’ attrition resistance and FTS stability, but decreases activity due to the suppression of further reduction of the catalysts. Moreover, the attrition resistance of the catalysts with the same silica content was greatly improved with an increase in hydroxyl number within silica sources, as well as the FTS activity and stability to some degree. Furthermore, the boron element was found to show remarkable promotion of FTS stability, and the promotion mechanism was discussed with regard to probable interactions between Fe and B, K and B, and SiO2 and B, etc. An optimized catalyst based on the results of this study was finalized, scaled up, and successfully applied in a megaton industrial slurry bubble FTS unit, exhibiting excellent FTS performance

Effects of Potassium Loading over Iron–Silica Interaction, Phase Evolution and Catalytic Behavior of Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis

Potassium (K) promoter and its loading contents were shown to have remarkable effects on the Fe–O–Si interaction of precipitated Fe/Cu/K/SiO2 catalysts for low-temperature Fischer-Tropsch synthesis (FTS). With the increase in K content from 2.3% (100 g Fe based) up to 7% in the calcined precursors, Fe–O–Si interaction was weakened, as reflected by ATR/FTIR, H2-TPR and XPS investigations. XRD results confirmed that the diffraction peak intensity from (510) facet of χ-Fe5C2 phase strengthened with increasing K loading, which indicates the crystallite size of χ-Fe5C2 increased with the increase in K contents either during the syngas reduction/carburization procedure or after FTS reaction. H2-TPH results indicated that more reactive surface carbon (alpha-carbon) was obtained over the higher K samples pre-carburized by syngas. Raman spectra illustrated that a greater proportion of graphitic carbon was accumulated over the surface of spent samples with higher K loading. At the same time, ATR-FTIR, XRD and Mössbauer spectra (MES) characterization results showed that a relatively higher level of bulk phase Fayalite (Fe2SiO4) species was observed discernibly in the lowest K loading sample (2.3 K%) in this work. The catalytic evaluation results showed that the CO conversion, CO2 selectivity and O/P (C2–C4) ratio increased progressively with the increasing K loading, whereas a monotonic decline in both CO conversion and O/P (C2–C4) ratio was observed on the highest K loading sample during c.a. 280 h of TOS