385 research outputs found
Besnoitia besnoiti infection alters both endogenous cholesterol de novo synthesis and exogenous LDL uptake in host endothelial cells
Besnoitia besnoiti, an apicomplexan parasite of cattle being considered as emergent in Europe, replicates fast in host endothelial cells during acute infection and is in considerable need for energy, lipids and other building blocks for offspring formation. Apicomplexa are generally considered as defective in cholesterol synthesis and have to scavenge cholesterol from their host cells for successful replication. Therefore, we here analysed the influence of B. besnoiti on host cellular endogenous cholesterol synthesis and on sterol uptake from exogenous sources. GC-MS-based profiling of cholesterol-related sterols revealed enhanced cholesterol synthesis rates in B. besnoiti-infected cells. Accordingly, lovastatin and zaragozic acid treatments diminished tachyzoite production. Moreover, increased lipid droplet contents and enhanced cholesterol esterification was detected and inhibition of the latter significantly blocked parasite proliferation. Furthermore, artificial increase of host cellular lipid droplet disposability boosted parasite proliferation. Interestingly, lectin-like oxidized low density lipoprotein receptor 1 expression was upregulated in infected endothelial hostcells, whilst low density lipoproteins (LDL) receptor was not affected by parasite infection. However, exogenous supplementations with non-modified and acetylated LDL both boosted B. besnoiti proliferation. Overall, current data show that B. besnoiti simultaneously exploits both, endogenous cholesterol biosynthesis and cholesterol uptake from exogenous sources, during asexual replication
A newly described strain of Eimeria arloingi (strain A) belongs to the phylogenetic group of ruminant-infecting pathogenic species, which replicate in host endothelial cells in vivo
Coccidiosis caused by Eimeria species is an important disease worldwide, particularly in ruminants and poultry. Eimeria infection can result in significant economic losses due to costs associated with treatment and slower growth rates, or even with mortality of heavily infected individuals. In goat production, a growing industry due to increasing demand for caprine products worldwide, coccidiosis is caused by several Eimeria species with E. arloingi and E. ninakohlyakimovae the most pathogenic. The aims of this study were genetic characterization of a newly isolated European E. arloingi strain (A) and determination of phylogenetic relationships with Eimeria species from other ruminants. Therefore, a DNA sequence of E. arloingi strain (A) containing 2290 consensus nucleotides (the majority of 18S rDNA, complete ITS-1 and 5.8S sequences, and the partial ITS-2) was amplified and phylogenetic relationship determined with the most similar sequences available on GenBank. The phylogenetic tree presented a branch constituted by bovine Eimeria species plus E. arloingi, and another one exclusively populated by ovine Eimeria species. Moreover, E. arloingi, E. bovis and E. zuernii, which all replicate in host intestinal endothelial cells of the lacteals, were found within the same cluster. This study gives new insights into the evolutionary phylogenetic relationships of this newly described caprine Eimeria strain and confirmed its close relationship to other highly pathogenic ruminant Eimeria species characterized by macromeront formation in host endothelial cells of the central lymph capillaries of the small intestine
JSENet: Joint Semantic Segmentation and Edge Detection Network for 3D Point Clouds
Semantic segmentation and semantic edge detection can be seen as two dual
problems with close relationships in computer vision. Despite the fast
evolution of learning-based 3D semantic segmentation methods, little attention
has been drawn to the learning of 3D semantic edge detectors, even less to a
joint learning method for the two tasks. In this paper, we tackle the 3D
semantic edge detection task for the first time and present a new two-stream
fully-convolutional network that jointly performs the two tasks. In particular,
we design a joint refinement module that explicitly wires region information
and edge information to improve the performances of both tasks. Further, we
propose a novel loss function that encourages the network to produce semantic
segmentation results with better boundaries. Extensive evaluations on S3DIS and
ScanNet datasets show that our method achieves on par or better performance
than the state-of-the-art methods for semantic segmentation and outperforms the
baseline methods for semantic edge detection. Code release:
https://github.com/hzykent/JSENetComment: Accepted to ECCV 2020, supplementary materials include
Anthropozoonotic parasites circulating in synanthropic and pacific colonies of South American sea lions (Otaria flavescens): non-invasive techniques data and a review of the literature
Since late 1970s, the southern Chilean city Valdivia constitutes home for a unique bachelor group of South American sea lions (Otaria flavescens), initially descendant from colonies at the Pacific coast, but now directly living in a freshwater habitat in close proximity to human population and a vast amount of wild and domestic animal species. In the framework of a parasitological monitoring program, 115 individual fecal samples were collected from synanthropic South American sea lions between March and May 2018. For comparative reasons, 79 individual fecal samples from two free-living O. flavescens colonies at the Pacific coast were also sampled. Coproscopical analyses revealed the presence of nine different parasite taxa in individual fecal samples, including two protozoan (Cryptosporidium spp. and Giardia spp.) and seven metazoan parasites (Anisakidae gen. spp., Diphyllobothriidae gen. spp., Ogmogaster heptalineatus, Trematoda indet. type 1, Trematoda indet. type 2, Otostrongylus circumlitus, and Parafilaroides spp.), and morphological and molecular characterizations of adult helminths confirmed identification of following species: Anisakis simplex/A. pegreffi, Pseudoterranova cattani, Contracaecum ogmorhini, and Adenocephalus pacificus. For the first time, the results of the current study show the presence of zoonotic relevant Giardia- and Cryptosporidium-infections in two free-ranging colonies of South American sea lions apart from human settlement. Furthermore, a detailed literature search of previous publications on the endoparasite fauna of South American sea lions was conducted, revealing reports of at least 50 protozoan and metazoan parasite taxa including findings of the current study. Thereby, at least 25 of reported taxa (50%) have been recorded to bear zoonotic potential. The present study illustrates a successful application of non-invasive screening methods and their applicability in the field of marine mammal parasitology, bringing new insights into the endogenous parasite fauna of South American sea lions in Southern Chile, including anthropozoonotic protozoan and metazoan taxa
Toxoplasma gondii Me49 and NED strains arrest host cell cycle progression and alter chromosome segregation in a strain-independent manner
Toxoplasma gondii is an obligate intracellular parasite that modulates a broad range of host cell functions to guarantee its intracellular development and replication. T. gondii includes three classical clonal lineages exhibiting different degrees of virulence. Regarding the genetic diversity of T. gondii circulating in Europe, type II strains and, to a lesser extent, type III strains are the dominant populations, both in humans and animals. Infections with the type I strain led to widespread parasite dissemination and death in mice, while type III is considered avirulent. Previously, we demonstrated that primary endothelial cells infected with the T. gondii RH strain (haplotype I) were arrested in the G2/M-phase transition, triggering cytokinesis failure and chromosome missegregation. Since T. gondii haplotypes differ in their virulence, we here studied whether T. gondii-driven host cell cycle perturbation is strain-dependent. Primary endothelial cells were infected with T. gondii Me49 (type II strain) or NED (type III strain), and their growth kinetics were compared up to cell lysis (6–30 h p. i.). In this study, only slight differences in the onset of full proliferation were observed, and developmental data in principle matched those of the RH strain. FACS-based DNA quantification to estimate cell proportions experiencing different cell cycle phases (G0/1-, S-, and G2/M-phase) revealed that Me49 and NED strains both arrested the host cell cycle in the S-phase. Cyclins A2 and B1 as key molecules of S- and M-phase were not changed by Me49 infection, while NED infection induced cyclin B1 upregulation. To analyze parasite-driven alterations during mitosis, we demonstrated that both Me49 and NED infections led to impaired host cellular chromosome segregation and irregular centriole overduplication. Moreover, in line with the RH strain, both strains boosted the proportion of binucleated cells within infected endothelial cell layers, thereby indicating enhanced cytokinesis failure. Taken together, we demonstrate that all parasite-driven host cell cycle arrest, chromosome missegregation, and binucleated phenotypes are T. gondii-specific but strain independent
Seasonal and spatial variations of nutrient content, oxygen demand and redox potential in sediments under a floating cage fish farm
Most reviews on environmental impacts of fish farming have emphasised that the most widely known effect is benthic enrichment beneath the sea farms. Marine fish farming is increasing rapidly in the Mediterranean coastal zone. It is characterised by clear water with high transparency, microtidal, oligotrophic and nutrient-poor sediments. The present paper discusses the results obtained in the analysis of the sediments beneath and surrounding the sea farm.En zonas templadas, como el Mediterráneo occidental, los impactos ambientales resultantes de la sedimentaciĂłn de materia orgánica particulada en el fondo marino bajo las instalaciones de una explotaciĂłn acuĂcola parecen estar determinados por factores como la producciĂłn, la batimetrĂa, la Ă©poca del año y la distancia a las dependencias. En este trabajo se evalĂşan las concentraciones de materia orgánica y de nutrientes y el potencial redox en los sedimentos de los fondos situados bajo las jaulas flotantes de una producciĂłn acuĂcola; los resultados permiten observar que en el transcurso de los meses de verano se producen aumentos en la concentraciĂłn de nutrientes y en la demanda de oxĂgeno y un descenso del potencial redox.Instituto Español de OceanografĂ
Uso de TIC en la enseñanza de energĂas renovables: aplicaciĂłn del HOMER a una problemática de diseño energĂ©tico
El diseño, desarrollo y apropiaciĂłn de tecnologĂas digitales son una realidad del siglo XXI que incluye todas las áreas del conocimiento y la producciĂłn. A diario se buscan soluciones tecnolĂłgicas innovadoras para ser incorporadas en proyectos de aplicaciĂłn en diversos ámbitos: educativo, social, cientĂfico y laboral. El desarrollo de recursos digitales ha llegado tambiĂ©n al campo de las energĂas renovables y se multiplican los programas informáticos de modelizaciĂłn de parques eĂłlicos, estudio de variables climáticas, dimensionamiento de biodigestores, etc... Los futuros tĂ©cnicos egresados de la Tecnicatura Superior en EnergĂas Renovables “Desarrollará competencias especĂficas del campo de la energĂa que requieren del tĂ©cnico el dominio de un “saber hacer” (…) IntegraciĂłn de clases teĂłrico-prácticas, priorizando el aprendizaje de construcciĂłn del conocimiento por sobre la exclusiva transmisiĂłn”. Es por ello que en los Talleres de EnergĂa EĂłlica y Solar, y en la asignatura IntroducciĂłn a las Herramientas de ComputaciĂłn se enfatiza el aprendizaje y utilizaciĂłn de programas especĂficos: HOMER, GEOSOL, WINDPRO, SIG EOLICO, etc. Se presenta pues una actividad desarrollada por alumnos de 2° año como ejemplo de aplicaciĂłn de uno de los programas mencionados en ambos talleres, de energĂa solar y eĂłlica.The design, development and appropriation of digital technologies are a reality in the XXI Century which includes all areas of knowledge and production. Every day innovative technological solutions are sought to be incorporated into application projects in several fields: educational, social, scientific and professional. The development of digital resources has also reached the field of renewable energies and there are many software tools to model wind farms, study climatic variables, size biodigesters, etc... The future graduates of the “Tecnicatura Superior en EnergĂas Renovables” (Renewable Energy Engineering) will: ... "Develop specific skills in the field of energy that require their mastery of know-how" (...) Integrate theoretical and practical classes, prioritizing knowledge construction over mere transmission". That is why in the workshops of Solar and Wind Energy, and the subject “Introduction to Software Tools”, the learning and use of specific software tools like HOMER, GEOSOL, WindPro, SIG WIND, etc. are emphasized. This activity developed by students of 2nd year is an example of application of the aforementioned software in both solar and wind energy workshops.AsociaciĂłn Argentina de EnergĂas Renovables y Medio Ambiente (ASADES
Socio-economic status and the risk of developing hand, hip or knee osteoarthritis: a region-wide ecological study
SummaryObjectiveTo determine the association between socio-economic status (SES) and risk of hand, hip or knee osteoarthritis (OA) at a population level.DesignRetrospective ecological study using the System for the Development of Research in Primary Care (SIDIAP) database (primary care anonymized records for >5 million people in Catalonia (Spain)). Urban residents >15 years old (2009–2012) were eligible. Outcomes: Validated area-based SES deprivation index MEDEA (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) was estimated for each area based on census data as well as incident diagnoses (ICD-10 codes) of hand, hip or knee OA (2009–2012). Zero-inflated Poisson models were fitted to study the association between MEDEA quintiles and the outcomes.ResultsCompared to the least deprived, the most deprived areas were younger (43.29 (17.59) vs 46.83 (18.49), years (Mean SD), had fewer women (49.1% vs 54.8%), a higher percentage of obese (16.2% vs 8.4%), smokers (16.9% vs 11.9%) and high-risk alcohol consumption subjects (1.5% vs 1.3%). Compared to the least deprived, the most deprived areas had an excess risk of OA: age-sex-adjusted Incidence Rate Ratio (IRR) 1.26 (1.11–1.42) for hand, 1.23 (1.17–1.29) hip, and 1.51 (1.45–1.57) knee. Adjustment for obesity attenuated this association: 1.06 (0.93–1.20), 1.04 (0.99–1.09), and 1.23 (1.19–1.28) respectively.ConclusionsDeprived areas have higher rates OA (hand, hip, knee). Their increased prevalence of obesity accounts for a 50% of the excess risk of knee OA observed. Public health interventions to reduce the prevalence of obesity in this population could reduce health inequalities
Environmentally friendly synthesized and magnetically recoverable designed ferrite photo-catalysts for wastewater treatment applications
Fenton processes are promising wastewater treatment alternatives for bio-recalcitrant compounds. Three different methods (i.e., reverse microemulsion, sol-gel, and combustion) were designed to synthesize environmentally friendly ferrites as magnetically recoverable catalysts to be applied for the decomposition of two pharmaceuticals (ciprofloxacin and carbamazepine) that are frequently detected in water bodies. The catalysts were used in a heterogeneous solar photo-Fenton treatment to save the cost of applying high-energy UV radiation sources, and was performed under a slightly basic pH to avoid metal leaching and adding salts for pH adjustment. All the developed catalysts resulted in the effective treatment of ciprofloxacin and carbamazepine in both synthetic and real domestic wastewater. In particular, the sol-gel synthesized ferrite was more magnetic and more suitable for reuse. The degradation pathways of both compounds were elucidated for this treatment. The degradation of ciprofloxacin involved attacks to the quinolone and piperazine rings. The degradation pathway of carbamazepine involved the formation of hydroxyl carbamazepine and dihydroxy carbamazepine before yielding acridine by hydrogen abstraction, decarboxylation, and amine cleavage, which would be further oxidized
Simultaneous and Positively Correlated NET Formation and Autophagy in Besnoitia besnoiti Tachyzoite-Exposed Bovine Polymorphonuclear Neutrophils
Given that B. besnoiti tachyzoites infect host endothelial cells of vessels in vivo, they become potential targets for professional phagocytes [e.g., polymorphonuclear neutrophils (PMN)] when in search for adequate host cells or in case of host cell lysis. It was recently reported that B. besnoiti-tachyzoites can efficiently be trapped by neutrophil extracellular traps (NETs) released by bovine PMN. So far, the potential role of autophagy in parasite-triggered NET formation is unclear. Thus, we here analyzed autophagosome formation and activation of AMP-activated protein kinase α (AMPKα) in potentially NET-forming innate leukocytes being exposed to B. besnoiti tachyzoites. Blood was collected from healthy adult dairy cows, and bovine PMN were isolated via density gradient centrifugation. Scanning electron microscopy confirmed PMN to undergo NET formation upon contact with B. besnoiti tachyzoites. Nuclear area expansion (NAE) analysis and cell-free and anchored NETs quantification were performed in B. besnoiti-induced NET formation. Interestingly, tachyzoites of B. besnoiti additionally induced LC3B-related autophagosome formation in parallel to NET formation in bovine PMN. Notably, both rapamycin- and wortmannin-treatments failed to influence B. besnoiti-triggered NET formation and autophagosome formation. Also, isolated NETs fail to induce autophagy suggesting independence between both cellular processes. Finally, enhanced phosphorylation of AMP activated kinase α (AMPKα), a key regulator molecule of autophagy, was observed within the first minutes of interaction in tachyzoite-exposed PMN thereby emphasizing that B. besnoiti-triggered NET formation indeed occurs in parallel to autophagy
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