Revisiting Ruddick: Feminism, pacifism and non-violence

This article explores feminist contentions over pacifism and non-violence in the contextof the Greenham Common Peace Camp in the 1980s and later developments offeminist Just War Theory. We argue that Sara Ruddick’s work puts feminist pacifism, its radical feminist critics and feminist just war theory equally into question. Although Ruddick does not resolve the contestations within feminism over peace, violence and the questions of war, she offers a productive way of holding the tension between them. In our judgment, her work is helpful not only for developing a feminist political response to the threats and temptations of violent strategies but also for thinking through the question of the relation between violence and politics as such

Hygrothermal simulation-informed design of mesoporous desiccants for optimised energy efficiency of mixed mode air conditioning systems

This paper describes an optimization technique using hygrothermal numerical modelling to determine an ideal and unknown isotherm in order to inform the design of optimised mesoporous desiccants. Their suitability for passive humidity buffering as well as their impact on energy efficiency was assessed when assisting a mixed mode air-conditioning (AC) system. Three clear stages of water vapour adsorption were found that strongly correspond to the Dw gradient when assessing the kinetics of adsorption and exchange rates for periodic moisture loads. Consistent agreement was found between the latent heat of dehumidification used by the AC system and the desiccant decay time after successive sorption loop cycles. This confirmed the material's suitability for specific applications and was found to be highly sensitive to the portion of the isotherm between φi,L - φi,U (Dw gradient), compared with full adsorption capacity (total w) when assessing total energy consumption. The experimental results of sorption kinetics appeared to be slightly underestimated between the Dw gradient and the response time to reach equilibrium moisture content (EMC). The major underestimations were found to be consistent with the kinetics of adsorption/desorption when analysing their significance based on w differences. These were largely attributed to a combination of adsorption kinetics (time-response) and adsorption/desorption hysteresis. However, this was not evident when comparing long-term experimental data and numerical estimations for water vapour sorption isotherms, since numerical model accurately predicted them. This suggests that both adsorption kinetics and the scanning curve prediction, within a hysteresis loop, are not accurately represented by current hygrothermal models and are hence a priority for future research

HIV/AIDS, demography and development: individual choices versus public policies in SSA

Despite the increasing rate of diffusion of effective therapies, the battle against HIV/AIDS in Sub-Saharan Africa (SSA) is far from being over. Three main challenges are that the epidemics might paralyse or reverse the fertility transition, the expansion of the resources needed to finance the fight against HIV, and the emerging resistance to anti-retroviral treatments. This research proposes a UGT-like model showing the complexity of the interplay amongst the (macro)economy, the epidemics, their endogenous feedback on mortality and fertility and the central role of policy actions aimed to fight HIV. The disease-induced increase in adult mortality can hamper economic development by its upward pressure on the precautionary demand for children and downward pressure on education. This can dramatically reduce physical and human capital accumulation

The PMC2NT domain of the catalytic exosome subunit Rrp6p provides the interface for binding with its cofactor Rrp47p, a nucleic acid-binding protein

The exosome complex is a key component of the cellular RNA surveillance machinery and is required for normal 3′ end processing of many stable RNAs. Exosome activity requires additional factors such as the Ski or TRAMP complexes to activate the complex or facilitate substrate binding. Rrp47p promotes the catalytic activity of the exosome component Rrp6p, but its precise function is unknown. Here we show that recombinant Rrp47p is expressed as an apparently hexameric complex that specifically binds structured nucleic acids. Furthermore, pull-down assays demonstrated that Rrp47p interacts directly with the N-terminal region of Rrp6p that contains the functionally uncharacterized PMC2NT domain. Strains expressing a mutant form of Rrp6p lacking the N-terminal region failed to accumulate Rrp47p at normal levels, exhibited a slow growth phenotype characteristic of rrp47-Δ mutants and showed RNA processing defects consistent with loss of Rrp47p function. These findings suggest Rrp47p promotes Rrp6p activity by facilitating binding via the PMC2NT domain to structural elements within RNA. Notably, characterized Rrp6p substrates such as the 5.8S+30 species are predicted to contain helices at their 3′ termini, while others such as intergenic or antisense cryptic unstable transcripts could potentially form extensive double-stranded molecules with overlapping mRNAs

Evidence for core exosome independent function of the nuclear exoribonuclease Rrp6p

The RNA exosome processes and degrades RNAs in archaeal and eukaryotic cells. Exosomes from yeast and humans contain two active exoribonuclease components, Rrp6p and Dis3p/Rrp44p. Rrp6p is concentrated in the nucleus and the dependence of its function on the nine-subunit core exosome and Dis3p remains unclear. We found that cells lacking Rrp6p accumulate poly(A)+ rRNA degradation intermediates distinct from those found in cells depleted of Dis3p, or the core exosome component Rrp43p. Depletion of Dis3p in the absence of Rrp6p causes a synergistic increase in the levels of degradation substrates common to the core exosome and Rrp6p, but has no effect on Rrp6p-specific substrates. Rrp6p lacking a portion of its C-terminal domain no longer co-purifies with the core exosome, but continues to carry out RNA 3′-end processing of 5.8S rRNA and snoRNAs, as well as the degradation of certain truncated Rrp6-specific rRNA intermediates. However, disruption of Rrp6p–core exosome interaction results in the inability of the cell to efficiently degrade certain poly(A)+ rRNA processing products that require the combined activities of Dis3p and Rrp6p. These findings indicate that Rrp6p may carry out some of its critical functions without physical association with the core exosome

Transcriptome-wide analysis of alternative routes for RNA substrates into the exosome complex

<div><p>The RNA exosome complex functions in both the accurate processing and rapid degradation of many classes of RNA. Functional and structural analyses indicate that RNA can either be threaded through the central channel of the exosome or more directly access the active sites of the ribonucleases Rrp44 and Rrp6, but it was unclear how many substrates follow each pathway <i>in vivo</i>. We used CRAC (UV crosslinking and analysis of cDNA) in growing cells to identify transcriptome-wide interactions of RNAs with the major nuclear exosome-cofactor Mtr4 and with individual exosome subunits (Rrp6, Csl4, Rrp41 and Rrp44) along the threaded RNA path. We compared exosome complexes lacking Rrp44 exonuclease activity, carrying a mutation in the Rrp44 S1 RNA-binding domain predicted to disfavor direct access, or with multiple mutations in Rrp41 reported to impede RNA access to the central channel <i>in vitro</i>. Preferential use of channel-threading was seen for mRNAs, 5S rRNA, scR1 (SRP) and aborted tRNAs transcripts. Conversely, pre-tRNAs preferentially accessed Rrp44 directly. Both routes participated in degradation and maturation of RNAPI transcripts, with hand-over during processing. Rrp41 mutations blocked substrate passage through the channel to Rrp44 only for cytoplasmic mRNAs, supporting the predicted widening of the lumen in the Rrp6-associated, nuclear complex. Many exosome substrates exhibited clear preferences for a specific path to Rrp44. Other targets showed redundancy, possibly allowing the efficient handling of highly diverse RNA-protein complexes and RNA structures. Both threading and direct access routes involve the RNA helicase Mtr4. mRNAs that are predominately nuclear or cytoplasmic exosome substrates can be distinguished <i>in vivo</i>.</p></div