Redox linked flavin sites in extracellular decaheme proteins involved in microbe-mineral electron transfer

Extracellular microbe-mineral electron transfer is a major driving force for the oxidation of organic carbon in many subsurface environments. Extracellular multi-heme cytochromes of the Shewenella genus play a major role in this process but the mechanism of electron exchange at the interface between cytochrome and acceptor is widely debated. The 1.8 Å x-ray crystal structure of the decaheme MtrC revealed a highly conserved CX8C disulfide that, when substituted for AX8A, severely compromised the ability of S. oneidensis to grow under aerobic conditions. Reductive cleavage of the disulfide in the presence of flavin mononucleotide (FMN) resulted in the reversible formation of a stable flavocytochrome. Similar results were also observed with other decaheme cytochromes, OmcA, MtrF and UndA. The data suggest that these decaheme cytochromes can transition between highly reactive flavocytochromes or less reactive cytochromes, and that this transition is controlled by a redox active disulfide that responds to the presence of oxygen

Culture-independent molecular analysis of bacterial diversity in uranium-ore/-mine waste-contaminated and non-contaminated sites from uranium mines

Soil, water and sediment samples collected from in and around Jaduguda, Bagjata and Turamdih mines were analyzed for physicochemical parameters and cultured, and yet to be cultured microbial diversity. Culturable fraction of microbial community measured as Colony Forming Unit (CFU) on R2A medium revealed microbes between 104 and 109 CFU/g sample. Community DNA was extracted from all the samples; 16S rRNA gene amplified, cloned and subject to Amplified Ribosomal DNA Restriction Analysis. Clones representing each OTU were selected and sequenced. Sequence analyses revealed that non-contaminated samples were mostly represented by Acidobacteria, Bacteroidetes, Firmicutes and Proteobacteria (β-, γ-, and/or δ-subdivisions) along with less frequent phyla Nitrospira, Deferribacteres, Chloroflexi. In contrast, samples obtained from highly contaminated samples showed distinct abundance of β-,γ- and α-Proteobacteria along with Acidobacteria,Bacteroidetes and members of Firmicutes, Chloroflexi, Candidate division, Planctomycete, Cyanobacteria and Actinobacteria as minor groups. Our data represented the baseline information on bacterial community composition within non-contaminated samples which could potentially be useful for assessing the impact of metal and radionuclides contamination due to uranium mine activities

Phase Separation of Rigid-Rod Suspensions in Shear Flow

We analyze the behavior of a suspension of rigid rod-like particles in shear flow using a modified version of the Doi model, and construct diagrams for phase coexistence under conditions of constant imposed stress and constant imposed strain rate, among paranematic, flow-aligning nematic, and log-rolling nematic states. We calculate the effective constitutive relations that would be measured through the regime of phase separation into shear bands. We calculate phase coexistence by examining the stability of interfacial steady states and find a wide range of possible ``phase'' behaviors.Comment: 23 pages 19 figures, revised version to be published in Physical Review

Barriers to Exercise in Younger and Older Non-Exercising Adult Women: A Cross Sectional Study in London, United Kingdom

A survey of 100 women in the south of London, United Kingdom (UK) compared exercise barrier intensities between non-exercising younger (20–27 years) and older (28–35 years) adult women; and examined childcare duties as perceived barriers to exercise. Perceived barriers to exercise were examined using an Exercise Benefits/Barriers Scale (EBBS) comprising four subscales (exercise milieu; time expenditure; physical exertion; family discouragement). Participants’ number of children was also noted. Non-exercising older women reported significantly higher total exercise barriers, as well as across three barrier subscales: exercise milieu, time expenditure, and family discouragement. For both age groups, significant correlation existed between number of children and women’s total exercise barrier scores. Number of children explained ≈25% and ≈30% of the variance of younger and older women’s total barrier scores respectively. For both women groups, the strongest correlation between exercise barrier and number of children was for the time expenditure subscale. Broad grouping of 20–35 year old non-exercising women does not reflect a homogenous sample. Age categories employing narrower age brackets are recommended. Issues surrounding family responsibilities e.g. childcare duties may be shared between these groups and require further research and policy attention

Models for synthetic biology

Synthetic biological engineering is emerging from biology as a distinct discipline based on quantification. The technologies propelling synthetic biology are not new, nor is the concept of designing novel biological molecules. What is new is the emphasis on system behavior

Redefining the Converted Jewish Self: Race, Religion and Israel's Bene Menashe

The Bene Menashe stem from a number of Christian groups of the Indo-Burmese borderland, some of whom back in the 1950s declared their descent from the Lost Tribes of Israel. In this article, I will use the example of the Bene Menashe migration to Israel to cast analytical light on different ways in which race and religion co-constitute each other in processes of transnational migration. To do so, I will focus on one specific aspect of the Bene Menashe migration—the way the community has to construct and enact their religious affiliation to be able to become Israeli citizens and to be considered part of the Jewish people by their “hosts.” I argue that, in the case of the Bene Menashe, race and religion co-produce each other in ways that reinforce racialized understandings of Judaism and Jewishness, and I suggest that what accounts for this phenomenon is that the opportunities that the Bene Menashe immigrants had in defining their religiosity in Israel were limited by the conditions of their migration, which developed against the backdrop of multiple colonial contexts. [Judaism, Israel, racialization, migration, religion

In the Margins: The Impact of Sexualised Images on the Mental Health of Ageing Women

This paper describes key findings of a study exploring how a cohort of 16 rural Australian women aged over 60 years think, feel and respond to the prevalence of sexualised imagery in the media. The qualitative research framework was informed by Feminist Standpoint Theory. Participants in three focus groups responded to semi-structured questions and prompts, interspersed with viewing examples of sexualised images. Five strong thematic categories emerged: concern for the harmful impacts of sexualised images on the vulnerable, the media’s portrayal of sexual content with a focus on physical appearance and youth, descriptions of the impact of viewing sexualised images, moderators of the impact of sexualised images on well-being, and marginalisation of women in the media. Findings from this research indicate that sexualised images in the media do have an impact on older women’s self image and mental health in numerous ways and in a range of situations. Emotional impacts included sadness, anger, concern, envy, desensitisation, marginalisation, and discomfort that their appearance was being judged by others. A strong sense of self apart from appearance, feeling valued by family and community, ignoring or overlooking media content, and being aware that media images are not real and attainable helped buffer the link between sexualised images and well-being. Another important finding is that the impact is variable: women may experience different responses to similar sexualised content depending on a range of social, health and lifestyle factors affecting them at any given time

Coupling and Elastic Loading Affect the Active Response by the Inner Ear Hair Cell Bundles

Active hair bundle motility has been proposed to underlie the amplification mechanism in the auditory endorgans of non-mammals and in the vestibular systems of all vertebrates, and to constitute a crucial component of cochlear amplification in mammals. We used semi-intact in vitro preparations of the bullfrog sacculus to study the effects of elastic mechanical loading on both natively coupled and freely oscillating hair bundles. For the latter, we attached glass fibers of different stiffness to the stereocilia and observed the induced changes in the spontaneous bundle movement. When driven with sinusoidal deflections, hair bundles displayed phase-locked response indicative of an Arnold Tongue, with the frequency selectivity highest at low amplitudes and decreasing under stronger stimulation. A striking broadening of the mode-locked response was seen with increasing stiffness of the load, until approximate impedance matching, where the phase-locked response remained flat over the physiological range of frequencies. When the otolithic membrane was left intact atop the preparation, the natural loading of the bundles likewise decreased their frequency selectivity with respect to that observed in freely oscillating bundles. To probe for signatures of the active process under natural loading and coupling conditions, we applied transient mechanical stimuli to the otolithic membrane. Following the pulses, the underlying bundles displayed active movement in the opposite direction, analogous to the twitches observed in individual cells. Tracking features in the otolithic membrane indicated that it moved in phase with the bundles. Hence, synchronous active motility evoked in the system of coupled hair bundles by external input is sufficient to displace large overlying structures

Notions of Well-Being, the State of Child Well-Being Research and the MYWEB Project

There has been a growing interest among academics, policy makers and practitioners in the subjective well-being of children and young people (CYP). The recognition of CYP’s rights to having a good childhood and good future life chances, coupled with the injunction from the New Sociology of Childhood to consult with CYP as active agents have resulted in an increasing number of studies on children and young people’s well-being at national and international levels. However, the design, content, and modes of data collection used in these surveys are influenced by the question of the extent to which the researchers view children and young people as similar or different to adults and which participatory models they are undertaking for the young people in the study. However, the design, content, and modes of data collection used in these surveys are influenced by a number of factors including conceptual underpinning of well-being, its measurement and participatory model(s) used by the researchers for children in those surveys. This chapter reviews these aspects before describing the structure of this book with summaries of each subsequent chapter