167 research outputs found

    Symbionts on the Brain: How Wolbachia Is Strictly Corralled in Some Neotropical Drosophila spp.

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    Wolbachia is a heritable alphaproteobacterial symbiont of arthropods and nematodes, famous for its repertoire of host manipulations, including cytoplasmic incompatibility. To be vertically transmitted, Wolbachia must efficiently colonize the female germ line, although somatic tissues outside the gonads are also infected. In Drosophila spp., Wolbachia is usually distributed systemically in multiple regions of the adult fly, but in some neotropical hosts, Wolbachia's only somatic niches are cerebral bacteriocyte-like structures and the ovarian follicle cells. In their recent article, Strunov and colleagues (A. Strunov, K. Schmidt, M. Kapun, and W. J. Miller. mBio 13:e03863-21, 2022, https://doi.org/10.1128/mbio.03863-21) compared the development of Drosophila spp. with systemic or restricted infections and demonstrated that the restricted pattern is determined in early embryogenesis by an apparently novel autophagic process, involving intimate interactions of Wolbachia with the endoplasmic reticulum. This work has implications not only for the evolution of neotropical Drosophila spp. but also for our understanding of how Wolbachia infections are controlled in other native or artificial hosts

    Mediation service at the Student Sports Club

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    Educational work in student sports is aimed at developing students’ competencies of personal and collective responsibility for the quality of self-realization in life. Integration of standards of professional, educational and sports activities in terms of goal setting ensures the achievement of personal results of participants of student sports clubs. The protection of the rights of student-athletes in the mediation (reconciliation) service implements educational and regulatory functions and justifies its necessity. The attitude to mediation as a way of settling disputes on the implementation of the rights of student-athletes justifies the expediency of the mediation service. The survey of participants and staff of the student club of the Higher School of Physical Culture and Sports of the Immanuel Kant Baltic Federal University (N = 61) proved the relevance of the problem of protecting the rights of student-athletes to participate in competitions and be admitted to sports teams (83.7%); the presence of competence deficits in sports ethics (78.7%); willingness to resolve a conflict with the leaders of a sports club and a sports team in the mediation service on the issue of sports sanctions for misconduct (73.8%); acceptance of mediation as a way to develop and conclude a mutually beneficial solution (93.4%); the likelihood of contractual capacity in conflict resolution based on a common interest in honest, fair play (95.1%); balance as an essential personality trait of the sports mediator (93.4%). The survey data determine the recommendations for the organization of mediation services in the sports student club: the structure of the educational work of the club; humanitarian service of legal protection and psychological support of the club members and employees; standardization of documentation, regulatory and methodological support of the club’s activities; regulation of friendly dispute resolution on the implementation of the rights of student-athletes

    Wolbachia Interferes with Ferritin Expression and Iron Metabolism in Insects

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    Wolbachia is an intracellular bacterium generally described as being a facultative reproductive parasite. However, Wolbachia is necessary for oogenesis completion in the wasp Asobara tabida. This dependence has evolved recently as a result of interference with apoptosis during oogenesis. Through comparative transcriptomics between symbiotic and aposymbiotic individuals, we observed a differential expression of ferritin, which forms a complex involved in iron storage. Iron is an essential element that is in limited supply in the cell. However, it is also a highly toxic precursor of Reactive Oxygen Species (ROS). Ferritin has also been shown to play a key role in host–pathogen interactions. Measuring ferritin by quantitative RT-PCR, we confirmed that ferritin was upregulated in aposymbiotic compared to symbiotic individuals. Manipulating the iron content in the diet, we showed that iron overload markedly affected wasp development and induced apoptotic processes during oogenesis in A. tabida, suggesting that the regulation of iron homeostasis may also be related to the obligate dependence of the wasp. Finally, we demonstrated that iron metabolism is influenced by the presence of Wolbachia not only in the obligate mutualism with A. tabida, but also in facultative parasitism involving Drosophila simulans and in Aedes aegypti cells. In these latter cases, the expression of Wolbachia bacterioferritin was also increased in the presence of iron, showing that Wolbachia responds to the concentration of iron. Our results indicate that Wolbachia may generally interfere with iron metabolism. The high affinity of Wolbachia for iron might be due to physiological requirement of the bacterium, but it could also be what allows the symbiont to persist in the organism by reducing the labile iron concentration, thus protecting the cell from oxidative stress and apoptosis. These findings also reinforce the idea that pathogenic, parasitic and mutualistic intracellular bacteria all use the same molecular mechanisms to survive and replicate within host cells. By impacting the general physiology of the host, the presence of a symbiont may select for host compensatory mechanisms, which extends the possible consequences of persistent endosymbiont on the evolution of their hosts

    High-efficiency freezing-induced loading of inorganic nanoparticles and proteins into micron- and submicron-sized porous particles

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    We demonstrate a novel approach to the controlled loading of inorganic nanoparticles and proteins into submicron- and micron-sized porous particles. The approach is based on freezing/thawing cycles, which lead to high loading densities. The process was tested for the inclusion of Au, magnetite nanoparticles, and bovine serum albumin in biocompatible vaterite carriers of micron and submicron sizes. The amounts of loaded nanoparticles or substances were adjusted by the number of freezing/thawing cycles. Our method afforded at least a three times higher loading of magnetite nanoparticles and a four times higher loading of protein for micron vaterite particles, in comparison with conventional methods such as adsorption and coprecipitation. The capsules loaded with magnetite nanoparticles by the freezing-induced loading method moved faster in a magnetic field gradient than did the capsules loaded by adsorption or coprecipitation. Our approach allows the preparation of multicomponent nanocomposite materials with designed properties such as remote control (e.g. via the application of an electromagnetic or acoustic field) and cargo unloading. Such materials could be used as multimodal contrast agents, drug delivery systems, and sensors

    Phase-Change Microcapsules with a Stable Polyurethane Shell through the Direct Crosslinking of Cellulose Nanocrystals with Polyisocyanate at the Oil/Water Interface of Pickering Emulsion

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    Phase-change materials (PCMs) attract much attention with regard to their capability of mitigating fossil fuel-based heating in in-building applications, due to the responsive accumulation and release of thermal energy as a latent heat of reversible phase transitions. Organic PCMs possess high latent heat storage capacity and thermal reliability. However, bare PCMs suffer from leakages in the liquid form. Here, we demonstrate a reliable approach to improve the shape stability of organic PCM n-octadecane by encapsulation via interfacial polymerization at an oil/water interface of Pickering emulsion. Cellulose nanocrystals are employed as emulsion stabilizers and branched oligo-polyol with high functionality to crosslink the polyurethane shell in reaction with polyisocyanate dissolved in the oil core. This gives rise to a rigid polyurethane structure with a high density of urethane groups. The formation of a polyurethane shell and successful encapsulation of n-octadecane is confirmed by FTIR spectroscopy, XRD analysis, and fluorescent confocal microscopy. Electron microscopy reveals the formation of non-aggregated capsules with an average size of 18.6 µm and a smooth uniform shell with the thickness of 450 nm. The capsules demonstrate a latent heat storage capacity of 79 J/g, while the encapsulation of n-octadecane greatly improves its shape and thermal stability compared with bulk paraffin

    Застосування оздоровчих систем з елементами дихальної гімнастики для покращення якості життя осіб третього віку

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    The aim of this study is the analysis of literary sources on the use of health systems containing elements of respiratory gymnastics to justify future experiment on introduction of the author’s Wellness program combines breathing exercises Bodyflex and breathing exercises Frolovs. The contingent of the experiment will be presented to the third age students at Lvov state University of physical culture. The Desk review confirmed the importance and necessity of searching the ways to improve the quality of the people of the third age life. This indicates the relevance of the scientific search for the experimental confirmation of the hypothesis on the application of innovative technology, based on combination of improving system Bodyflex and respiratory gymnastics Frolovs.Целью данного исследования является анализ литературных источников по использованию оздоровительных систем, содержащих элементы дыхательной гимнастики, для обоснования эксперимента по внедрению авторской оздоровительной программы, сочетающего дыхательную гимнастику Бодифлекс и дыхательную гимнастику Фролова. Контингент исследуемых будет представлен слушателями Университета третьего возраста при Львовском государственном университете физической культуры. Результатами аналитического обзора подтверждена важность и необходимость поиска путей улучшения качества жизни людей третьего возраста. Это указывает на актуальность научного поиска по экспериментальному подтверждению гипотезы об эффективности применения инновационной технологии в основе которой лежит сочетание оздоровительной системы Бодифлекс и дыхательной гимнастики Фролова.Метою даного дослідження є аналіз літературних джерел із використання оздоровчих систем, що містять елементи дихальної гімнастики, для обґрунтування майбутнього експерименту з впровадження авторської оздоровчої програми, що поєднує дихальну гімнастику Бодіфлекс та дихальну гімнастику Фролова. Контингент експерименту буде представлений слухачами Університету третього віку при Львівському державному університеті фізичної культури. За результатами аналітичного огляду підтверджено важливість і необхідність пошуку шляхів покращення якості життя людей третього віку. Це вказує на актуальність наукового пошуку щодо експериментального підтвердження гіпотези про евективність застосування інноваційної технології в основі якої лежить поєднання оздоровчої системи Бодіфлекс та дихальної гімнастики Фролова

    Chiral photonic super-crystals based on helical van der Waals homostructures

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    Chirality is probably the most mysterious among all symmetry transformations. Very readily broken in biological systems, it is practically absent in naturally occurring inorganic materials and is very challenging to create artificially. Chiral optical wavefronts are often used for the identification, control and discrimination of left- and right-handed biological and other molecules. Thus, it is crucially important to create materials capable of chiral interaction with light, which would allow one to assign arbitrary chiral properties to a light field. In this paper, we utilized van der Waals technology to assemble helical homostructures with chiral properties (e. g. circular dichroism). Because of the large range of van der Waals materials available such helical homostructures can be assigned with very flexible optical properties. We demonstrate our approach by creating helical homostructures based on multilayer As2_2S3_3, which offers the most pronounced chiral properties even in thin structures due to its strong biaxial optically anisotropy. Our work showcases that the chirality of an electromagnetic system may emerge at an intermediate level between the molecular and the mesoscopic one due to the tailored arrangement of non-chiral layers of van der Waals crystals and without additional patterning

    Polyurethane/<i>n</i>-Octadecane Phase-Change Microcapsules via Emulsion Interfacial Polymerization: The Effect of Paraffin Loading on Capsule Shell Formation and Latent Heat Storage Properties.

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    Organic phase-change materials (PCMs) hold promise in developing advanced thermoregulation and responsive energy systems owing to their high latent heat capacity and thermal reliability. However, organic PCMs are prone to leakages in the liquid state and, thus, are hardly applicable in their pristine form. Herein, we encapsulated organic PCM n-Octadecane into polyurethane capsules via polymerization of commercially available polymethylene polyphenylene isocyanate and polyethylene glycol at the interface oil-in-water emulsion and studied how various n-Octadecane feeding affected the shell formation, capsule structure, and latent heat storage properties. The successful shell polymerization and encapsulation of n-Octadecane dissolved in the oil core was verified by confocal microscopy and Fourier-transform infrared spectroscopy. The mean capsule size varied from 9.4 to 16.7 µm while the shell was found to reduce in thickness from 460 to 220 nm as the n-Octadecane feeding increased. Conversely, the latent heat storage capacity increased from 50 to 132 J/g corresponding to the growth in actual n-Octadecane content from 25% to 67% as revealed by differential scanning calorimetry. The actual n-Octadecane content increased non-linearly along with the n-Octadecane feeding and reached a plateau at 66-67% corresponded to 3.44-3.69 core-to-monomer ratio. Finally, the capsules with the reasonable combination of structural and thermal properties were evaluated as a thermoregulating additive to a commercially available paint

    Anti-filarial Activity of Antibiotic Therapy Is Due to Extensive Apoptosis after Wolbachia Depletion from Filarial Nematodes

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    Filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility and viability and thus has great promise as a novel approach for treating filarial diseases. However, little is known concerning the basis for this mutualistic relationship. Here we demonstrate using whole mount confocal microscopy that an immediate response to Wolbachia depletion is extensive apoptosis in the adult germline, and in the somatic cells of the embryos, microfilariae and fourth-stage larvae (L4). Surprisingly, apoptosis occurs in the majority of embryonic cells that had not been infected prior to antibiotic treatment. In addition, no apoptosis occurs in the hypodermal chords, which are populated with large numbers of Wolbachia, although disruption of the hypodermal cytoskeleton occurs following their depletion. Thus, the induction of apoptosis upon Wolbachia depletion is non-cell autonomous and suggests the involvement of factors originating from Wolbachia in the hypodermal chords. The pattern of apoptosis correlates closely with the nematode tissues and processes initially perturbed following depletion of Wolbachia, embryogenesis and long-term sterilization, which are sustained for several months until the premature death of the adult worms. Our observations provide a cellular mechanism to account for the sustained reductions in microfilarial loads and interruption of transmission that occurs prior to macrofilaricidal activity following antibiotic therapy of filarial nematodes

    Combinations of the azaquinazoline anti-Wolbachia agent, AWZ1066S, with benzimidazole anthelmintics synergise to mediate sub-seven-day sterilising and curative efficacies in experimental models of filariasis

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    Lymphatic filariasis and onchocerciasis are two major neglected tropical diseases that are responsible for causing severe disability in 50 million people worldwide, whilst veterinary filariasis (heartworm) is a potentially lethal parasitic infection of companion animals. There is an urgent need for safe, short-course curative (macrofilaricidal) drugs to eliminate these debilitating parasite infections. We investigated combination treatments of the novel anti-Wolbachia azaquinazoline small molecule, AWZ1066S, with benzimidazole drugs (albendazole or oxfendazole) in up to four different rodent filariasis infection models: Brugia malayi—CB.17 SCID mice, B. malayi—Mongolian gerbils, B. pahangi—Mongolian gerbils, and Litomosoides sigmodontis—Mongolian gerbils. Combination treatments synergised to elicit threshold (>90%) Wolbachia depletion from female worms in 5 days of treatment, using 2-fold lower dose-exposures of AWZ1066S than monotherapy. Short-course lowered dose AWZ1066S-albendazole combination treatments also delivered partial adulticidal activities and/or long-lasting inhibition of embryogenesis, resulting in complete transmission blockade in B. pahangi and L. sigmodontis gerbil models. We determined that short-course AWZ1066S-albendazole co-treatment significantly augmented the depletion of Wolbachia populations within both germline and hypodermal tissues of B. malayi female worms and in hypodermal tissues in male worms, indicating that anti-Wolbachia synergy is not limited to targeting female embryonic tissues. Our data provides pre-clinical proof-of-concept that sub-seven-day combinations of rapid-acting novel anti-Wolbachia agents with benzimidazole anthelmintics are a promising curative and transmission-blocking drug treatment strategy for filarial diseases of medical and veterinary importance
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