68 research outputs found

    Histone H3K56 Acetylation, CAF1, and Rtt106 Coordinate Nucleosome Assembly and Stability of Advancing Replication Forks

    Get PDF
    Chromatin assembly mutants accumulate recombinogenic DNA damage and are sensitive to genotoxic agents. Here we have analyzed why impairment of the H3K56 acetylation-dependent CAF1 and Rtt106 chromatin assembly pathways, which have redundant roles in H3/H4 deposition during DNA replication, leads to genetic instability. We show that the absence of H3K56 acetylation or the simultaneous knock out of CAF1 and Rtt106 increases homologous recombination by affecting the integrity of advancing replication forks, while they have a minor effect on stalled replication fork stability in response to the replication inhibitor hydroxyurea. This defect in replication fork integrity is not due to defective checkpoints. In contrast, H3K56 acetylation protects against replicative DNA damaging agents by DNA repair/tolerance mechanisms that do not require CAF1/Rtt106 and are likely subsequent to the process of replication-coupled nucleosome deposition. We propose that the tight connection between DNA synthesis and histone deposition during DNA replication mediated by H3K56ac/CAF1/Rtt106 provides a mechanism for the stabilization of advancing replication forks and the maintenance of genome integrity, while H3K56 acetylation has an additional, CAF1/Rtt106-independent function in the response to replicative DNA damage

    Methodology of calculation of construction and hydrodynamic parameters of a foam layer apparatus for mass-transfer processes

    Get PDF
    Промислова реалізація методу стабілізації газорідинного шару дозволяє значно розширити галузь застосування пінних апаратів і відкриває нові можливості інтенсифікації технологічних процесів з одночасним створенням маловідходних технологій. У статті встановлені основні параметри, що впливають на гідродинаміку пінних апаратів, розглянуті основні конструкції та режими роботи пінних апаратів. Виявлено зв'язок гідродинамічних параметрів. Розглянуто гідродинамічні закономірності пінного шару. Вказані фактори, що впливають на процес масообміну, як в газовій, так і в рідкій фазах. Проведений аналіз ряду досліджень показав, що перспективним напрямком інтенсифікації процесу масообміну є розробка апаратів з трифазним псевдозрідженим шаром зрошуваної насадки складних форм із сітчастих матеріалів. Отже, необхідне проведення спеціальних досліджень гідродинамічних режимів роботи апарату з сітчастою насадкою і визначенням параметрів, що впливають на швидкість переходу насадки з одного режиму в інший.Industrial implementation of the stabilization method of the gas-liquid layer can significantly expand the field of use of foaming apparatus and opens up new opportunities for intensifying technological processes with the simultaneous creation of low-waste technologies. The article establishes the basic parameters influencing the hydrodynamics of foam apparatus, considers the basic constructions and operating modes of foam apparatus. The connection of hydrodynamic parameters is revealed. The hydrodynamic laws of the foam layer are considered. The indicated factors affecting the process of mass transfer, both in the gas and in the liquid phases. The conducted analysis of a number of studies showed that the perspective direction of intensification of the mass transfer process is the development of apparatuses with a three-phase fluidized bed of an irrigated nozzle of complex forms with mesh materials

    Nanocomposites: synthesis, structure, properties and new application opportunities

    Full text link

    Profession, market and class: Nurse migration and the remaking of division and disadvantage

    No full text
    Aims and objectives. This article aims to analyse the part played by successive waves of nurse migration in changing patterns of division and disadvantage within nursing. We argue that migration has in part acted to reinforce disadvantage based on class and gender, race and ethnicity and identify the influence of changes in nursing structure and commercialization of care in these processes. Background, design and methods. The historical analysis of division within nursing and the impact of migration are based on secondary sources (literature review) and primary research undertaken by ourselves and colleagues. The paper develops a concept of 'remaking' disadvantage drawing on analysis in social history of the interplay between agency and economic position in the 'making' of class. It uses the extended case method to focus on the residential care sector, showing how global and national influences operate at the frontline of service delivery. Results. We show how social class and gender, race and ethnicity have interacted and are reflected in the division of labour within nursing. We demonstrate how the employment conditions of nurse migrants have reinforced patterns of disadvantage. The case study of the residential care home sector deepens our analysis of intersecting sources of professional disadvantage including aspects of commercialization, in a sector where they have severe effects for vulnerable staff and patients. Conclusions. In the UK, migrant professional nurses have repeatedly acted both as a highly valued labour force on whom patients and clients rely and as involuntary contributors to remaking disadvantage. This situation is sustained by the current international labour market and rising commercialization which facilitate nurse migration and the segmentation of care work based on a 'pecking order' of specialties that reinforce existing divisions of social class, gender and race within nursing. Relevance to clinical practice. Migrant nurses play a key role in the delivery of 'frontline' care to patients. The role many currently play reinforces disadvantage within nursing in ways that are problematic for the profession, patients and clients. The recognition and valuing of their skills is critical to the promotion of their own morale which in turn has an impact on their relationship with colleagues and the delivery of patient and client care
    corecore