392 research outputs found
The bacteriohopanepolyol inventory of novel aerobic methane oxidising bacteria reveals new biomarker signatures of aerobic methanotrophy in marine systems
Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to trace AMO events, especially at times when the role of methane in the carbon cycle was more pronounced than today. AMO bacteria are known to synthesise bacteriohopanepolyol (BHP) lipids. Preliminary evidence pointed towards 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) being a characteristic biomarker for Type I methanotrophs. Here, the BHP compositions were examined for species of the recently described novel Type I methanotroph bacterial genera Methylomarinum and Methylomarinovum, as well as for a novel species of a Type I Methylomicrobium. Aminopentol was the most abundant BHP only in Methylomarinovum caldicuralii, while Methylomicrobium did not produce aminopentol at all. In addition to the expected regular aminotriol and aminotetrol BHPs, novel structures tentatively identified as methylcarbamate lipids related to C-35 amino-BHPs (MCBHPs) were found to be synthesised in significant amounts by some AMO cultures. Subsequently, sediments and authigenic carbonates from methane-influenced marine environments were analysed. Most samples also did not contain significant amounts of aminopentol, indicating that aminopentol is not a useful biomarker for marine aerobic methanotophic bacteria. However, the BHP composition of the marine samples do point toward the novel MC-BHPs components being potential new biomarkers for AMO
Magnetoelectric ordering of BiFeO3 from the perspective of crystal chemistry
In this paper we examine the role of crystal chemistry factors in creating
conditions for formation of magnetoelectric ordering in BiFeO3. It is generally
accepted that the main reason of the ferroelectric distortion in BiFeO3 is
concerned with a stereochemical activity of the Bi lone pair. However, the lone
pair is stereochemically active in the paraelectric orthorhombic beta-phase as
well. We demonstrate that a crucial role in emerging of phase transitions of
the metal-insulator, paraelectric-ferroelectric and magnetic disorder-order
types belongs to the change of the degree of the lone pair stereochemical
activity - its consecutive increase with the temperature decrease. Using the
structural data, we calculated the sign and strength of magnetic couplings in
BiFeO3 in the range from 945 C down to 25 C and found the couplings, which
undergo the antiferromagnetic-ferromagnetic transition with the temperature
decrease and give rise to the antiferromagnetic ordering and its delay in
regard to temperature, as compared to the ferroelectric ordering. We discuss
the reasons of emerging of the spatially modulated spin structure and its
suppression by doping with La3+.Comment: 18 pages, 5 figures, 3 table
Stepping across the line: Information sharing, truth-telling and the role of the personal carer in the Australian Nursing Home
The author draws on an Australian study using multiple qualitative methods to investigate truth telling in aged care. Thematic analysis of data from five nursing homes involving 23 personal care assistants revealed participants’ role understanding as influencing their perceptions about truth telling in practice. Five themes emerged: role as the happy comfort carer, division of labor, division of disclosure, role tension and frustration, and managing the division of disclosure. Role emphasis on comfort and happiness and a dominant perception that telling the truth can cause harm mean that disclosure will be withheld, edited, or partial. Participants’ role understanding divides labor and disclosure responsibility between the personal carer and registered nurse. Personal carers’ strategies for managing the division of disclosure include game playing, obfuscation, lying (denial), and the use of nonverbals. These perceptions about personal carer role, information sharing, and truth telling are paramount for understanding and improving nursing home eldercare
Neutrinos in a gravitational background: a test for the universality of the gravitational interaction
In this work we propose an extended formulation for the interaction between
neutrinos and gravitational fields. It is based on the parametrized
post-Newtonian aproach, and includes a violation of the universality of the
gravitational interaction which is non diagonal in the weak flavor space. We
find new effects that are not considered in the standard scenario for violation
of the equivalence principle. They are of the same order as the effects
produced by the Newtonian potential, but they are highly directional dependent
and could provide a very clean test of that violation. Phenomenological
consequences are briefly discussed.Comment: 18 pages, revtex, no figure
`The varieties of effects resulting from such morbific causes as are capable of rendering more vivid the feelings of the mind' by S. Hibbert (1825)
Реализация интегративного подхода при изучении дисциплины "Патологическая физиология" в медицинском университете
МЕДИЦИНСКИЕ ВУЗЫМЕДИЦИНСКИЕ ИНСТИТУТЫОБРАЗОВАНИЕ МЕДИЦИНСКОЕПЕДАГОГИЧЕСКИЕ ТЕХНОЛОГИИОБРАЗОВАТЕЛЬНЫЙ ПРОЦЕССУЧЕБНЫЕ ДИСЦИПЛИНЫМЕЖДИСЦИПЛИНАРНЫЕ СВЯЗИМЕЖДИСЦИПЛИНАРНАЯ ИНТЕГРАЦИЯИНТЕГРАТИВНЫЙ ПОДХОДПАТОФИЗИОЛОГИЯ (ДИСЦИПЛИНА)ПАТОЛОГИЧЕСКАЯ ФИЗИОЛОГИЯ (ДИСЦИПЛИНА)ОБУЧЕНИЕ /МЕТОДЫПРЕПОДАВАНИЕМОТИВАЦИ
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